The Next Big COVID Variant Could Be a Triple Whammy Nightmare

https://www.yahoo.com/news/next-big-covid-variant-could-100250868.html

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Even as daily new COVID cases set all-time records and hospitals fill up, epidemiologists have arrived at a perhaps surprising consensus. Yes, the latest Omicron variant of the novel coronavirus is bad. But it could have been a lot worse.

Even as cases have surged, deaths haven’t—at least not to the same degree. Omicron is highly transmissible but generally not as severe as some older variants—“lineages” is the scientific term.

We got lucky. But that luck might not hold. Many of the same epidemiologists who have breathed a sigh of relief over Omicron’s relatively low death rate are anticipating that the next lineage might be much worse.

The New Version of the Omicron Variant Is a Sneaky Little Bastard

Fretting over a possible future lineage that combines Omicron’s extreme transmissibility with the severity of, say, the previous Delta lineage, experts are beginning to embrace a new public health strategy that’s getting an early test run in Israel: a four-shot regimen of messenger-RNA vaccine.

“I think this will be the strategy going forward,” Edwin Michael, an epidemiologist at the Center for Global Health Infectious Disease Research at the University of South Florida, told The Daily Beast.

Omicron raised alarms in health agencies all over the world in late November after officials in South Africa reported the first cases. Compared to older lineages, Omicron features around 50 key mutations, some 30 of which are on the spike protein that helps the virus to grab onto our cells.

Some of the mutations are associated with a virus’s ability to dodge antibodies and thus partially evade vaccines. Others are associated with higher transmissibility. The lineage’s genetic makeup pointed to a huge spike in infections in the unvaccinated as well as an increase in milder “breakthrough” infections in the vaccinated.

That’s exactly what happened. Health officials registered more than 10 million new COVID cases the first week of January. That’s nearly double the previous worst week for new infections, back in May. Around 3 million of those infections were in the United States, where Omicron coincided with the Thanksgiving, Christmas, and New Year holidays and associated traveling and family gatherings.

But mercifully, deaths haven’t increased as much as cases have. Worldwide, there were 43,000 COVID deaths the first week of January—fewer than 10,000 of them in the U.S. While deaths tend to lag infections by a couple weeks, Omicron has been dominant long enough that it’s increasingly evident there’s been what statisticians call a “decoupling” of cases and fatalities.

“We can say we dodged a bullet in that Omicron does not appear to cause as serious of a disease,” Stephanie James, the head of a COVID testing lab at Regis University in Colorado, told The Daily Beast. She stressed that data is still being gathered, so we can’t be certain yet that the apparent decoupling is real.

Assuming the decoupling is happening, experts attribute it to two factors. First, Omicron tends to infect the throat without necessarily descending to the lungs, where the potential for lasting or fatal damage is much, much higher. Second, by now, countries have administered nearly 9.3 billion doses of vaccine—enough for a majority of the world’s population to have received at least one dose.

Omicron Shows the Unvaccinated Will Never Be Safe

In the United States, 73 percent of people have gotten at least one dose. Sixty-two percent have gotten two doses of the best mRNA vaccines. A third have received a booster dose.

Yes, Omicron has some ability to evade antibodies, meaning the vaccines are somewhat less effective against this lineage than they are against Delta and other older lineages. But even when a vaccine doesn’t prevent an infection, it usually greatly reduces its severity.

For many vaccinated people who’ve caught Omicron, the resulting COVID infection is mild. “A common cold or some sniffles in a fully vaxxed and boosted healthy individual,” is how Eric Bortz, a University of Alaska-Anchorage virologist and public health expert, described it to The Daily Beast.

All that is to say, Omicron could have been a lot worse. Viruses evolve to survive. That can mean greater transmissibility, antibody-evasion or more serious infection. Omicron mutated for the former two. There’s a chance some future Sigma or Upsilon lineage could do all three.

When it comes to viral mutations, “extreme events can occur at a non-negligible rate, or probability, and can lead to large consequences,” Michael said. Imagine a lineage that’s as transmissible as Omicron but also attacks the lungs like Delta tends to do. Now imagine that this hypothetical lineage is even more adept than Omicron at evading the vaccines.

2022’s Hottest New Illness: Flurona

That would be the nightmare lineage. And it’s entirely conceivable it’s in our future. There are enough vaccine holdouts, such as the roughly 50 million Americans who say they’ll never get jabbed, that the SARS-CoV-2 pathogen should have ample opportunities for mutation.

“As long as we have unvaccinated people in this country—and across the globe—there is the potential for new and possibly more concerning viral variants to arise,” Aimee Bernard, a University of Colorado immunologist, told The Daily Beast.

Worse, this ongoing viral evolution is happening against a backdrop of waning immunity. Antibodies, whether vaccine-induced or naturally occurring from past infection, fade over time. It’s not for no reason that health agencies in many countries urge booster doses just three months after initial vaccination. The U.S. Centers for Disease Control and Prevention is an outlier, and recommends people get boosted after five months.

A lineage much worse than Omicron could evolve at the same time that antibodies wane in billions of people all over the world. That’s why many experts believe the COVID vaccines will end up being annual or even semi-annual jabs. You’ll need a fourth jab, a fifth jab, a sixth jab, et cetera, forever.

Israel, a world leader in global health, is already turning that expectation into policy. Citing multiple studies that showed a big boost in antibodies with an additional dose of mRNA and no safety concerns, the country’s health ministry this week began offering a fourth dose to anyone over the age of 60, who tend to be more vulnerable to COVID than younger people.

That should be the standard everywhere, Ali Mokdad, a professor of health metrics sciences at the University of Washington Institute for Health, told The Daily Beast. “Scientifically, they’re right,” he said of the Israeli health officials.

If there’s a downside, it’s that there are still a few poorer countries—in Africa, mostly—where many people still struggle to get access to any vaccine, let alone boosters and fourth doses. If and when other richer countries follow Israel’s lead and begin offering additional jabs, there’s some risk of even greater inequity in global vaccine distribution.

“The downside is for the rest of the world,” Mokdad said. “I’m waiting to get my first dose and you guys are getting a fourth?”

The solution isn’t to deprive people of the doses they need to maintain their protection against future—and potentially more dangerous—lineages. The solution, for vaccine-producing countries, is to further boost production and double down on efforts to push vaccines out to the least privileged communities.

A sense of urgency is key. For all its rapid spread, Omicron has actually gone fairly easy on us. Sigma or Upsilon might not.

The 1918 flu is even more relevant in 2022 thanks to omicron

Over the past two years, historians and analysts have compared the coronavirus to the 1918 flu pandemic. Many of the mitigation practices used to combat the spread of the coronavirus, especially before the development of the vaccines, have been the same as those used in 1918 and 1919 — masks and hygiene, social distancing, ventilation, limits on gatherings (particularly indoors), quarantines, mandates, closure policies and more.

Yet, it may be that only now, in the winter of 2022, when Americans are exhausted with these mitigation methods, that a comparison to the 1918 pandemic is most apt.

The highly contagious omicron variant has rendered vaccines much less effective at preventing infections, thus producing skyrocketing caseloads. And that creates a direct parallel with the fall of 1918, which provides lessons for making January as painless as possible.

In February and March 1918, an infectious flu emerged. It spread from Kansas, through World War I troop and material transports, filling military post hospitals and traveling across the Atlantic and around the world within six months. Cramped quarters and wartime transport and industry generated optimal conditions for the flu to spread, and so, too, did the worldwide nature of commerce and connection. But there was a silver lining: Mortality rates were very low.

In part because of press censorship of anything that might undermine the war effort, many dismissed the flu as a “three-day fever,” perhaps merely a heavy cold, or simply another case of the grippe (an old-fashioned word for the flu).

Downplaying the flu led to high infection rates, which increased the odds of mutations. And in the summer of 1918, a more infectious variant emerged. In August and September, U.S. and British intelligence officers observed outbreaks in Switzerland and northern Europe, writing home with warnings that went largely unheeded.

Unsurprisingly then, this seemingly more infectious, much more deadly variant of H1N1 traveled west across the Atlantic, producing the worst period of the pandemic in October 1918. Nearly 200,000 Americans died that month. After a superspreading Liberty Loan parade at the end of September, Philadelphia became an epicenter of the outbreak. At its peak, nearly 700 Philadelphians died per day.

Once spread had begun, mitigation methods such as closures, distancing, mask-wearing and isolating those infected couldn’t stop it, but they did save many lives and limited suffering by slowing infections and spread. The places that fared best implemented proactive restrictions early; they kept them in place until infections and hospitalizations were way down, then opened up gradually, with preparations to reimpose measures if spread returned or rates elevated, often ignoring the pleas of special interests lobbying hard for a complete reopening.

In places in the United States where officials gave in to public fatigue and lobbying to remove mitigation methods, winter surges struck. Although down from October’s highs, these surges were still usually far worse than those in the cities and regions that held steady.

In Denver, in late November 1918, an “amusement” lobby — businesses and leaders invested in keeping theaters, movie houses, pool halls and other public venues open — successfully pressured the mayor and public health officials to rescind and then revise a closure order. This, in turn, generated what the Rocky Mountain News called “almost indescribable confusion,” followed by widespread public defiance of mask and other public health prescriptions.

In San Francisco, where resistance was generally less successful than in Denver, there was significant buy-in for a second round of masking and public health mandates in early 1919 during a new surge. But opposition created an issue. An Anti-Mask League formed, and public defiance became more pronounced. Eventually anti-maskers and an improving epidemic situation combined to end the “masked” city’s second round of mask and public health mandates.

The takeaway: Fatigue and removing mitigation methods made things worse. Public officials needed to safeguard the public good, even if that meant unpopular moves.

The flu burned through vulnerable populations, but by late winter and early spring 1919, deaths and infections dropped rapidly, shifting toward an endemic moment — the flu would remain present, but less deadly and dangerous.

Overall, nearly 675,000 Americans died during the 1918-19 flu pandemic, the majority during the second wave in the autumn of 1918. That was 1 in roughly 152 Americans (with a case fatality rate of about 2.5 percent). Worldwide estimates differ, but on the order of 50 million probably died in the flu pandemic.

In 2022, we have far greater biomedical and technological capacity enabling us to sequence mutations, understand the physics of aerosolization and develop vaccines at a rapid pace. We also have a far greater public health infrastructure than existed in 1918 and 1919. Even so, it remains incredibly hard to stop infectious diseases, particularly those transmitted by air. This is complicated further because many of those infected with the coronavirus are asymptomatic. And our world is even more interconnected than in 1918.

That is why, given the contagiousness of omicron, the lessons of the past are even more important today than they were a year ago. The new surge threatens to overwhelm our public health infrastructure, which is struggling after almost two years of fighting the pandemic. Hospitals are experiencing staff shortages (like in fall 1918). Testing remains problematic.

And ominously, as in the fall of 1918, Americans fatigued by restrictions and a seemingly endless pandemic are increasingly balking at following the guidance of public health professionals or questioning why their edicts have changed from earlier in the pandemic. They are taking actions that, at the very least, put more vulnerable people and the system as a whole at risk — often egged on by politicians and media figures downplaying the severity of the moment.

Public health officials also may be repeating the mistakes of the past. Conjuring echoes of Denver in late 1918, under pressure to prioritize keeping society open rather than focusing on limiting spread, the Centers for Disease Control and Prevention changed its isolation recommendations in late December. The new guidelines halved isolation time and do not require a negative test to reenter work or social gatherings.

Thankfully, we have an enormous advantage over 1918 that offers hope. Whereas efforts to develop a flu vaccine a century ago failed, the coronavirus vaccines developed in 2020 largely prevent severe illness or death from omicron, and the companies and researchers that produced them expect a booster shot tailored to omicron sometime in the winter or spring. So, too, we have antivirals and new treatments that are just becoming available, though in insufficient quantities for now.

Those lifesaving advantages, however, can only help as much as Americans embrace them. Only by getting vaccinated, including with booster shots, can Americans prevent the health-care system from being overwhelmed. But the vaccination rate in the country remains a relatively paltry 62 percent, and only a scant 1 in 5 have received a booster shot. And as in 1918, some of the choice rests with public officials. Though restrictions may not be popular, officials can reimpose them — offering public support where necessary to those for whom compliance would create hardship — and incentivize and mandate vaccines, taking advantage of our greater medical technology.

As the flu waned in 1919, one Portland, Ore., health official reflected that “the biggest thing we have had to fight in the influenza epidemic has been apathy, or perhaps the careless selfishness of the public.”

The same remains true today.

Vaccines, new treatments and century-old mitigation strategies such as masks, distancing and limits on gatherings give us a pathway to prevent the first six weeks of 2022 from being like the fall of 1918. And encouraging news about the severity of omicron provides real optimism that an endemic future — in which the coronavirus remains but poses far less of a threat — is near. The question is whether we get there with a maximum of pain or a minimum. The choice is ours.

Why are so many vaccinated people getting COVID-19 lately?

https://www.yahoo.com/news/why-many-vaccinated-people-getting-050338384.html

Why are so many vaccinated people getting COVID-19 lately?

A couple of factors are at play, starting with the emergence of the highly contagious omicron variant. Omicron is more likely to infect people, even if it doesn’t make them very sick, and its surge coincided with the holiday travel season in many places.

People might mistakenly think the COVID-19 vaccines will completely block infection, but the shots are mainly designed to prevent severe illness, says Louis Mansky, a virus researcher at the University of Minnesota. 

And the vaccines are still doing their job on that front, particularly for people who’ve gotten boosters.

Two doses of the Pfizer-BioNTech or Moderna vaccines or one dose of the Johnson & Johnson vaccine still offer strong protection against serious illness from omicron. While those initial doses aren’t very good at blocking omicron infection, boosters — particularly with the Pfizer and Moderna vaccines — rev up levels of the antibodies to help fend off infection.

Omicron appears to replicate much more efficiently than previous variants. And if infected people have high virus loads, there’s a greater likelihood they’ll pass it on to others, especially the unvaccinated. Vaccinated people who get the virus are more likely to have mild symptoms, if any, since the shots trigger multiple defenses in your immune system, making it much more difficult for omicron to slip past them all.

Advice for staying safe hasn’t changed. Doctors say to wear masks indoors, avoid crowds and get vaccinated and boosted. Even though the shots won’t always keep you from catching the virus, they’ll make it much more likely you stay alive and out of the hospital.

Experts say COVID-19 cases don’t tell whole story

https://thehill.com/homenews/administration/587405-experts-say-covid-19-cases-dont-tell-whole-story?userid=12325

Coronavirus Pandemic (COVID-19) - Statistics and Research - Our World in  Data


For nearly two years, Americans have looked carefully at coronavirus case numbers in the country and in their local states and towns to judge the risk of the disease.

Surging case numbers signaled growing dangers, while falling case numbers were a relief and a signal to let one’s guard down in terms of gathering with friends and families and taking part in all kinds of events.

But with much of the nation’s population vaccinated and boosted and the country dealing with a new COVID-19 surge from omicron — a highly contagious variant that some studies suggest may not be as severe as previous variants — public health officials are debating whether the nation needs to shift its thinking.

Many people are going to get omicron — but those that are vaccinated and boosted are unlikely to suffer dire symptoms.

As a result, hospitalizations and deaths are the markers that government officials need to monitor carefully to ensure the safety of communities as the nation learns to live with COVID-19.

“This is the new normal,” said Leana Wen, a public health professor at George Washington University and former Baltimore health commissioner. “This is what we will have to accept as we transition from the emergency of COVID-19 to living with it as part of the new normal.”

David Dowdy, an epidemiologist at Johns Hopkins Bloomberg School of Public Health, said that Americans all need to shift to focus on hospitalizations over cases as we enter into another year of the pandemic.

“I think that we need to start training ourselves to look, first of all, at hospitalizations. I think hospitalizations are a real-time indicator of how serious things are,” he said.

Rising case numbers still say something about the disease, and the spikes from omicron are leading to real concerns.

Anthony Fauci, the government’s top infectious disease expert, noted on Sunday that even if omicron leads to less severe cases of COVID-19, if it infects tens of millions it will have the potential of straining resources in hospitals.

“If you have many, many, many more people with a less level of severity, that might kind of neutralize the positive effect of having less severity when you have so many more people,” he said during an appearance on ABC’s “This Week.”

At the same time, the nation must get used to dealing with the coronavirus as it would deal with an annual flu season. It’s a challenge for most parts of American life, from schools and businesses that have to consider worker and student safety, to professional sports leagues that must decide how long someone sits out after a positive test — even if the person is vaccinated and not symptomatic.

“Omicron in a way is the first test of what it means to live with COVID-19,” said Wen. “And by that I mean we are going to see many people getting infected but as long as our hospital systems are not overwhelmed and as long as vaccinated people are generally protected against severe outcomes, that is how we end the pandemic phase and switch into the endemic phase.”

The omicron strain is so infectious that once the current surge has faded in the United States, it’s likely a large majority of the population will either have been vaccinated against COVID-19 or have been infected, experts say. At that point, the focus should shift away from preventing infection to preventing serious illness, multiple experts said, a message already being echoed in some corners of the White House.

Many states have been seeing staggering numbers of positive tests and lines for COVID-19 testing that stretch for several blocks. Washington, D.C., and New York state have set records in recent days for the number of new cases reported as omicron barrels through the population.

But even with case totals surpassing last year’s numbers, President Biden and White House officials have been quick to point out that hospitalizations haven’t been as high as the numbers seen in the winter of 2020.

“Because we have so many vaccinated and boosted, we’re not seeing hospitalizations drive as sharply as we did in March of 2020 or even this past fall. America has made progress; things are better,” Biden said on Monday on a White House COVID-19 response team call with the National Governors Association to discuss the administration’s response to the omicron variant.

“But we do know that with rising cases, we still have tens of millions of unvaccinated people and we’re seeing hospitalizations rise,” he added, saying that some hospitals are going to get overrun both in terms of equipment and staff.

The White House pointed to Biden’s remarks last week when asked about whether the president wants Americans and health experts to take the emphasis off of case numbers and put it on hospitalizations.

“Because omicron spreads so easily, we’ll see some fully vaccinated people get COVID, potentially in large numbers. There will be positive cases in every office, even here in the White House, among the vaccinated … from omicron. But these cases are highly unlikely to lead to serious illness,” Biden said on Dec. 21.

Chief of staff Ron Klain on Monday retweeted a CNN report about how hospitalizations are about 70 percent less than what they were around the last peak in September, but that COVID-19 cases in unvaccinated Americans could end up overwhelming health systems.

Health experts have suggested the White House’s shift in messaging away from a focus on the number of cases is a sign of what’s to come as the pandemic eventually becomes endemic.

“For two years, infections always preceded hospitalizations which preceded deaths, so you could look at infections and know what was coming,” Ashish Jha, dean of the Brown University School of Public Health, said Sunday on ABC. “Omicron changes that. This is the shift we’ve been waiting for in many ways.”

Dowdy said positive tests are also up because people are getting tested before visiting relatives.

“If a lot of people are testing positive because they are asymptomatic and wanting to make sure that they can travel etc., having a lot of those kinds of cases is not a big problem,” he said.

“In fact, that’s a good thing. It means that we’re doing the right thing as a country to define those cases,” Dowdy added.

Lawrence Gostin, a professor of global health at Georgetown University, said the shift away from tracking case numbers as a way to measure the pandemic means devoting more resources toward treatment options like the Pfizer antiviral pill.

Gostin also said testing should increasingly be used to self-diagnose so individuals can get proper treatment, rather than testing for the purpose of stopping the spread of the virus.

“The White House has got a very difficult balancing act. Certainly for now it’s going to have to emphasize the idea of masking and distancing for the purpose of protecting the health system,” Gostin said.

“We can’t live our lives in a bubble to prevent us from getting a pathogen that’s so contagious that you can’t avoid it if you’re going to be circulating and living a life in this world,” he continued. “What it means to transition to a normal life or more normal life is you have to focus not so much on preventing cases, but on preventing hospitalizations and deaths.”

Health officials say omicron variant likely to cause record-high coronavirus cases, hospitalizations in U.S.

Top government health officials on Sunday warned that the United States will probably see record numbers of coronavirus cases and hospitalizations as the omicron variant spreads rapidly and forces Americans to again grapple with the dangers of a pandemic that has upended life around the globe.

“Unfortunately, I think that that is going to happen. We are going to see a significant stress in some regions of the country on the hospital system, particularly in those areas where you have a low level of vaccination,” Anthony S. Fauci, the nation’s leading infectious-disease specialist, said on CNN’s “State of the Union” when asked whether the United States could see record numbers of cases, hospitalizations and deaths.

Fauci described the variant as “extraordinary” in its transmissibility, with a doubling time of two to three days. It accounts for 50 percent of coronavirus cases in parts of the country, which meant it would almost certainly take over as the dominant variant in the United States, he added.

“It is going to be a tough few weeks, months, as we get deeper into the winter,” Fauci said.

On CBS News’s “Face the Nation,” Francis Collins, director of the National Institutes of Health, said that cases will rise steeply over the next couple of weeks and that the country could soon see 1 million new cases a day tied to the omicron variant, dramatically exceeding the record of about 250,000 new cases per day set in January.

“The big question is, are those million cases going to be sick enough to need health care and especially hospitalization?” Collins said. “We’re just holding our breath to see how severe this will be.”

Fauci and Collins painted a stark but realistic picture of the winter ahead, on the heels of a week of coronavirus-related setbacks. Coronavirus cases, hospitalizations and deaths rose across much of the country last week, with officials warning of a surge just as millions of Americans — already weary after nearly two years of the pandemic — are expected to travel for Christmas and New Year’s. On Friday, Pfizer and BioNTech announced that coronavirus vaccines for children younger than 5 would be pushed back further into 2022, as the companies modified their trials to include a third dose. On Sunday, New York, one of the country’s early epicenters in the pandemic, reported 22,478 cases.

Health officials have continued to urge the unvaccinated to get their shots and those who have received only two doses of either the Pfizer or Moderna mRNA vaccines to get booster doses. Vaccines cannot be the only layer of protection against the omicron variant, Fauci said, but defeating the pandemic would not be possible without them.

There are still safe ways for vaccinated people to get together for the holidays, including wearing a mask while traveling, testing beforehand and knowing the vaccination status of everyone present at indoor celebrations, Fauci said on “Face the Nation.”

“If you do these things, I do believe that you can feel quite comfortable with a family setting,” he said. “Nothing is 100 percent risk-free, but I think if you do the things that I just mentioned, you’d actually mitigate that risk enough to feel comfortable about being able to enjoy the holiday.”

Collins stopped short of urging people to cancel holiday plans but said travel will be risky even for vaccinated people.

“This virus is going to be all around us,” he said. “I’m not going to say you shouldn’t travel, but you should do so very carefully. … People are going, ‘I’m so sick of hearing this,’ and I am, too. But the virus is not sick of us, and it is still out there looking for us, and we’ve got to double down on these things if we’re going to get through the next few months.”

Doctors, nurses and others are warning that the nation’s health system continues to be strained by an unending stream of coronavirus cases. Confirmed U.S. coronavirus infections have surpassed more than 128,000 per day and confirmed virus deaths are near 1,300 per day, according to The Washington Post’s rolling seven-day average.

“For people trained to save lives, this moment is frustrating, exhausting and heartbreaking,” the American Hospital Association, the American Medical Association and the American Nurses Association said in a joint statement on Friday, urging more Americans to get booster shots.

Public health experts are bracing for a winter surge of cases driven by the omicron variant, which can evade some protection conferred by vaccinations and prior infections, as well as cases linked to the delta variant. Officials caution that they are still relying on preliminary data about the omicron variant’s severity compared with earlier forms of the virus.

President Biden plans to address the nation Tuesday on the status of the country’s fight against the virus, the White House said Saturday.

“We are prepared for the rising case levels,” White House press secretary Jen Psaki wrote on Twitter, adding that Biden “will detail how we will respond to this challenge. He will remind Americans that they can protect themselves from severe illness from COVID-19 by getting vaccinated and getting their booster shot when they are eligible.”

The speech, coming just before Christmas and New Year’s Day, underlines Biden’s struggle to contain the pandemic nearly a year into office. On top of the emergence of new variants and attendant challenges, the administration has at times faced criticism for what some have described as mixed signals.

Biden won high marks from the public during the first half of the year as cases declined, the country opened up from shutdowns and vaccines became widely available. But the past few months have been more difficult. After he gave a speech on July 4 saying the country was “closer than ever to declaring our independence from a deadly virus,” the situation started changing. Case rates increased as the delta variant gained a foothold and many Americans refused to get vaccinated.

And despite Biden’s promise that at-home rapid tests would become a widely available tool to fight the coronavirus, the tests remain hard to find in many parts of the country and are more expensive than in some other places across the globe.

Fauci conceded Sunday that the administration needed to do better on increasing the availability of at-home coronavirus rapid tests, though he emphasized that the country was in a much better place than it was a year ago, with 200 million to 500 million tests available per month, many of them free.

“We’re going in the right direction,” he said on CNN. “We really need to flood the system with testing. We need to have tests available for anyone who wants them, particularly when we’re in a situation right now where people are going to be gathering.”

The omicron variant also has challenged the nation’s coronavirus medicine cabinet, with evidence that mutations will wipe out or weaken the effectiveness of treatments that can reduce the virus’s severity and keep people out of hospitals. As a result, the Biden administration around Thanksgiving paused distribution of sotrovimab, the one monoclonal antibody that remains effective against the omicron variant, with senior officials such as David Kessler calculating that the drug should be maximally deployed when the variant becomes more prevalent.

By Thursday, administration officials decided to resume shipments of the drug, amid indicators that the omicron variant was spreading faster in states such as New York and Washington than data published by the Centers for Disease Control and Preventionearlier in the week indicated, said two officials with knowledge of the deliberations.

“Shipment of product will begin soon, and jurisdictions will see product arrive as early as Tuesday, December 21, 2021,” the federal health agency said in a statement on Friday, announcing that about 55,000 doses of sotrovimab would soon go out.

Doctors said they were desperate for treatments like sotrovimab as emergency rooms begin to crowd and case numbers soar.

“Too slow! We are already seeing widespread omicron,” texted one infectious-disease doctor at a large New York City hospital, who estimated that at least 50 percent of patients had contracted the variant and requested confidentiality to discuss patient care. “It’s a lot of hospitalizations that could have potentially [been] averted because of slow response.”

Fauci said Sunday that he expected it to be months before antiviral drugs can be mass-produced and available to anyone who needs them. While he did not foresee the kind of shutdowns that were put in place in the early days of the pandemic, Fauci also noted that it would be difficult to keep the virus under control when there remained “about 50 million people in the country who are eligible to be vaccinated who are not vaccinated.”

Similarly, several governors on Sunday shied away from the possibility of implementing more shutdowns to fight the spread of the new variant. Maryland Gov. Larry Hogan (R) said on “Fox News Sunday” that his state, which has seen a 150 percent increase in hospitalizations over the past two weeks, was not considering shutdowns and instead was putting more resources into testing and encouraging vaccinations and boosters. New Jersey Gov. Phil Murphy (D) said on the same show that shutdowns remained “on the table” but that he didn’t think such a move was likely because a high percentage of the state’s population was vaccinated.

Colorado Gov. Jared Polis (D) emphasized that people in his state should keep themselves safe with “individual freedom and local control.” He also said Colorado officials were looking to change the definition of “fully vaccinated” to include three shots, as health officials in the country and around the world have signaled in recent days they are also considering.

“That’s certainly where it’s headed,” Polis said on NBC News’s “Meet the Press.” “I wish they’d stop talking about [the third shot] as a booster. It really is a three-dose vaccine.”

CDC: Omicron accounted for 73% of recent COVID-19 cases

COVID testing in NYC

The Omicron variant accounted for more than 73% of recent COVID-19 cases in the U.S., according to Centers for Disease Control and Prevention’s updated data released on Monday.

The big picture: The data showed nearly a six-fold increase in Omicron’s share of COVID-19 infections in just one week.

What they’re saying: “These numbers are stark, but they’re not surprising,” said Rochelle Walensky, the CDC’s director, adding that the growing infections reflect what has been seen in other countries.

  • While the Delta variant still drives up a lot of new infections, Walensky told AP she anticipates “that over time that Delta will be crowded out by Omicron.”

What’s next: President Biden on Tuesday will deliver a speech outlining new steps the administration will take to address the rapid spread of the new variant.

America Is Not Ready for Omicron

America was not prepared for COVID-19 when it arrived. It was not prepared for last winter’s surge. It was not prepared for Delta’s arrival in the summer or its current winter assault. More than 1,000 Americans are still dying of COVID every day, and more have died this year than last. Hospitalizations are rising in 42 states. The University of Nebraska Medical Center in Omaha, which entered the pandemic as arguably the best-prepared hospital in the country, recently went from 70 COVID patients to 110 in four days, leaving its staff “grasping for resolve,” the virologist John Lowe told me. And now comes Omicron.

Will the new and rapidly spreading variant overwhelm the U.S. health-care system? The question is moot because the system is already overwhelmed, in a way that is affecting all patients, COVID or otherwise. “The level of care that we’ve come to expect in our hospitals no longer exists,” Lowe said.

The real unknown is what an Omicron cross will do when it follows a Delta hook. Given what scientists have learned in the three weeks since Omicron’s discovery, “some of the absolute worst-case scenarios that were possible when we saw its genome are off the table, but so are some of the most hopeful scenarios,” Dylan Morris, an evolutionary biologist at UCLA, told me. In any case, America is not prepared for Omicron. The variant’s threat is far greater at the societal level than at the personal one, and policy makers have already cut themselves off from the tools needed to protect the populations they serve. Like the variants that preceded it, Omicron requires individuals to think and act for the collective good—which is to say, it poses a heightened version of the same challenge that the U.S. has failed for two straight years, in bipartisan fashion.

The coronavirus is a microscopic ball studded with specially shaped spikes that it uses to recognize and infect our cells. Antibodies can thwart such infections by glomming onto the spikes, like gum messing up a key. But Omicron has a crucial advantage: 30-plus mutations that change the shape of its spike and disable many antibodies that would have stuck to other variants. One early study suggests that antibodies in vaccinated people are about 40 times worse at neutralizing Omicron than the original virus, and the experts I talked with expect that, as more data arrive, that number will stay in the same range. The implications of that decline are still uncertain, but three simple principles should likely hold.

First, the bad news: In terms of catching the virus, everyone should assume that they are less protected than they were two months ago. As a crude shorthand, assume that Omicron negates one previous immunizing event—either an infection or a vaccine dose. Someone who considered themselves fully vaccinated in September would be just partially vaccinated now (and the official definition may change imminently). But someone who’s been boosted has the same ballpark level of protection against Omicron infection as a vaccinated-but-unboosted person did against Delta. The extra dose not only raises a recipient’s level of antibodies but also broadens their range, giving them better odds of recognizing the shape of even Omicron’s altered spike. In a small British study, a booster effectively doubled the level of protection that two Pfizer doses provided against Omicron infection.

Second, some worse news: Boosting isn’t a foolproof shield against Omicron. In South Africa, the variant managed to infect a cluster of seven people who were all boosted. And according to a CDC report, boosted Americans made up a third of the first known Omicron cases in the U.S. “People who thought that they wouldn’t have to worry about infection this winter if they had their booster do still have to worry about infection with Omicron,” Trevor Bedford, a virologist at Fred Hutchinson Cancer Research Center, told me. “I’ve been going to restaurants and movies, and now with Omicron, that will change.”

Third, some better news: Even if Omicron has an easier time infecting vaccinated individuals, it should still have more trouble causing severe disease. The vaccines were always intended to disconnect infection from dangerous illness, turning a life-threatening event into something closer to a cold. Whether they’ll fulfill that promise for Omicron is a major uncertainty, but we can reasonably expect that they will. The variant might sneak past the initial antibody blockade, but slower-acting branches of the immune system (such as T cells) should eventually mobilize to clear it before it wreaks too much havoc.

To see how these principles play out in practice, Dylan Morris suggests watching highly boosted places, such as Israel, and countries where severe epidemics and successful vaccination campaigns have given people layers of immunity, such as Brazil and Chile. In the meantime, it’s reasonable to treat Omicron as a setback but not a catastrophe for most vaccinated people. It will evade some of our hard-won immune defenses, without obliterating them entirely. “It was better than I expected, given the mutational profile,” Alex Sigal of the Africa Health Research Institute, who led the South African antibody study, told me. “It’s not going to be a common cold, but neither do I think it will be a tremendous monster.”

That’s for individuals, though. At a societal level, the outlook is bleaker.

Omicron’s main threat is its shocking speed, as my colleague Sarah Zhang has reported. In South Africa, every infected person has been passing the virus on to 3–3.5 other people—at least twice the pace at which Delta spread in the summer. Similarly, British data suggest that Omicron is twice as good at spreading within households as Delta. That might be because the new variant is inherently more transmissible than its predecessors, or because it is specifically better at moving through vaccinated populations. Either way, it has already overtaken Delta as the dominant variant in South Africa. Soon, it will likely do the same in Scotland and Denmark. Even the U.S., which has much poorer genomic surveillance than those other countries, has detected Omicron in 35 states. “I think that a large Omicron wave is baked in,” Bedford told me. “That’s going to happen.”

More positively, Omicron cases have thus far been relatively mild. This pattern has fueled the widespread claim that the variant might be less severe, or even that its rapid spread could be a welcome development. “People are saying ‘Let it rip’ and ‘It’ll help us build more immunity,’ that this is the exit wave and everything’s going to be fine and rosy after,” Richard Lessells, an infectious-disease physician at the University of KwaZulu-Natal, in South Africa, told me. “I have no confidence in that.”

To begin with, as he and others told me, that argument overlooks a key dynamic: Omicron might not actually be intrinsically milder. In South Africa and the United Kingdom, it has mostly infected younger people, whose bouts of COVID-19 tend to be less severe. And in places with lots of prior immunity, it might have caused few hospitalizations or deaths simply because it has mostly infected hosts with some protection, as Natalie Dean, a biostatistician at Emory University, explained in a Twitter thread. That pattern could change once it reaches more vulnerable communities. (The widespread notion that viruses naturally evolve to become less virulent is mistaken, as the virologist Andrew Pekosz of Johns Hopkins University clarified in The New York Times.) Also, deaths and hospitalizations are not the only fates that matter. Supposedly “mild” bouts of COVID-19 have led to cases of long COVID, in which people struggle with debilitating symptoms for months (or even years), while struggling to get care or disability benefits.

And even if Omicron is milder, greater transmissibility will likely trump that reduced virulence. Omicron is spreading so quickly that a small proportion of severe cases could still flood hospitals. To avert that scenario, the variant would need to be substantially milder than Delta—especially because hospitals are already at a breaking point. Two years of trauma have pushed droves of health-care workers, including many of the most experienced and committed, to quit their job. The remaining staff is ever more exhausted and demoralized, and “exceptionally high numbers” can’t work because they got breakthrough Delta infections and had to be separated from vulnerable patients, John Lowe told me. This pattern will only worsen as Omicron spreads, if the large clusters among South African health-care workers are any indication. “In the West, we’ve painted ourselves into a corner because most countries have huge Delta waves and most of them are stretched to the limit of their health-care systems,” Emma Hodcroft, an epidemiologist at the University of Bern, in Switzerland, told me. “What happens if those waves get even bigger with Omicron?”

The Omicron wave won’t completely topple America’s wall of immunity but will seep into its many cracks and weaknesses. It will find the 39 percent of Americans who are still not fully vaccinated (including 28 percent of adults and 13 percent of over-65s). It will find other biologically vulnerable people, including elderly and immunocompromised individuals whose immune systems weren’t sufficiently girded by the vaccines. It will find the socially vulnerable people who face repeated exposures, either because their “essential” jobs leave them with no choice or because they live in epidemic-prone settings, such as prisons and nursing homes. Omicron is poised to speedily recap all the inequities that the U.S. has experienced in the pandemic thus far.

Here, then, is the problem: People who are unlikely to be hospitalized by Omicron might still feel reasonably protected, but they can spread the virus to those who are more vulnerable, quickly enough to seriously batter an already collapsing health-care system that will then struggle to care for anyone—vaccinated, boosted, or otherwise. The collective threat is substantially greater than the individual one. And the U.S. is ill-poised to meet it.

America’s policy choices have left it with few tangible options for averting an Omicron wave. Boosters can still offer decent protection against infection, but just 17 percent of Americans have had those shots. Many are now struggling to make appointments, and people from rural, low-income, and minority communities will likely experience the greatest delays, “mirroring the inequities we saw with the first two shots,” Arrianna Marie Planey, a medical geographer at the University of North Carolina at Chapel Hill, told me. With a little time, the mRNA vaccines from Pfizer and Moderna could be updated, but “my suspicion is that once we have an Omicron-specific booster, the wave will be past,” Trevor Bedford, the virologist, said.

Two antiviral drugs now exist that could effectively keep people out of the hospital, but neither has been authorized and both are expensive. Both must also be administered within five days of the first symptoms, which means that people need to realize they’re sick and swiftly confirm as much with a test. But instead of distributing rapid tests en masse, the Biden administration opted to merely make them reimbursable through health insurance. “That doesn’t address the need where it is greatest,” Planey told me. Low-wage workers, who face high risk of infection, “are the least able to afford tests up front and the least likely to have insurance,” she said. And testing, rapid or otherwise, is about to get harder, as Omicron’s global spread strains both the supply of reagents and the capacity of laboratories.

Omicron may also be especially difficult to catch before it spreads to others, because its incubation period—the window between infection and symptoms—seems to be very short. At an Oslo Christmas party, almost three-quarters of attendees were infected even though all reported a negative test result one to three days before. That will make Omicron “harder to contain,” Lowe told me. “It’s really going to put a lot of pressure on the prevention measures that are still in place—or rather, the complete lack of prevention that’s still in place.”

The various measures that controlled the spread of other variants—masks, better ventilation, contact tracing, quarantine, and restrictions on gatherings—should all theoretically work for Omicron too. But the U.S. has either failed to invest in these tools or has actively made it harder to use them. Republican legislators in at least 26 states have passed laws that curtail the very possibility of quarantines and mask mandates. In September, Alexandra Phelan of Georgetown University told me that when the next variant comes, such measures could create “the worst of all worlds” by “removing emergency actions, without the preventive care that would allow people to protect their own health.” Omicron will test her prediction in the coming weeks.

The longer-term future is uncertain. After Delta’s emergence, it became clear that the coronavirus was too transmissible to fully eradicate. Omicron could potentially shunt us more quickly toward a different endgameendemicitythe point when humanity has gained enough immunity to hold the virus in a tenuous stalemate—albeit at significant cost. But more complicated futures are also plausible. For example, if Omicron and Delta are so different that each can escape the immunity that the other induces, the two variants could co-circulate. (That’s what happened with the viruses behind polio and influenza B.)

Omicron also reminds us that more variants can still arise—and stranger ones than we might expect. Most scientists I talked with figured the next one to emerge would be a descendant of Delta, featuring a few more mutational bells and whistles. Omicron, however, is “dramatically different,” Shane Crotty, from the La Jolla Institute for Immunology, told me. “It showed a lot more evolutionary potential than I or others had hoped for.” It evolved not from Delta but from older lineages of SARS-CoV-2, and seems to have acquired its smorgasbord of mutations in some hidden setting: perhaps a part of the world that does very little sequencing, or an animal species that was infected by humans and then transmitted the virus back to us, or the body of an immunocompromised patient who was chronically infected with the virus. All of these options are possible, but the people I spoke with felt that the third—the chronically ill patient—was most likely. And if that’s the case, with millions of immunocompromised people in the U.S. alone, many of whom feel overlooked in the vaccine era, will more weird variants keep arising? Omicron “doesn’t look like the end of it,” Crotty told me. One cause for concern: For all the mutations in Omicron’s spike, it actually has fewer mutations in the rest of its proteins than Delta did. The virus might still have many new forms to take.

Vaccinating the world can curtail those possibilities, and is now an even greater matter of moral urgency, given Omicron’s speed. And yet, people in rich countries are getting their booster six times faster than those in low-income countries are getting their first shot. Unless the former seriously commits to vaccinating the world—not just donating doses, but allowing other countries to manufacture and disseminate their own supplies—“it’s going to be a very expensive wild-goose chase until the next variant,” Planey said.

Vaccines can’t be the only strategy, either. The rest of the pandemic playbook remains unchanged and necessary: paid sick leave and other policies that protect essential workers, better masks, improved ventilation, rapid tests, places where sick people can easily isolate, social distancing, a stronger public-health system, and ways of retaining the frayed health-care workforce. The U.S. has consistently dropped the ball on many of these, betting that vaccines alone could get us out of the pandemic. Rather than trying to beat the coronavirus one booster at a time, the country needs to do what it has always needed to do—build systems and enact policies that protect the health of entire communities, especially the most vulnerable ones

Individualism couldn’t beat Delta, it won’t beat Omicron, and it won’t beat the rest of the Greek alphabet to come.

Self-interest is self-defeating, and as long as its hosts ignore that lesson, the virus will keep teaching it.

Parents Still Have a Thanksgiving Problem

a turkey with vaccine syringes as tail feathers

A first COVID shot will give kids some protection, but none of them will be fully vaccinated until the beginning of December.

For many, many months now, 7-year-old Alain Bell has been keeping a very ambitious list of the things he wants to do after he gets his COVID-19 shots: travel (to Disneyworld or Australia, ideally); play more competitive basketball; go to “any restaurants that have french fries, which are my favorite food,” he told me over the phone.

These are very good kid goals, and they are, at last, in sight. On Tuesday evening, about as early as anyone in the general public could, Alain nabbed his first dose of Pfizer’s newly cleared pediatric COVID-19 vaccine. The needle delivered “a little poke,” he said, but also a huge injection of excitement and relief. Since his father, a critical-care physician, was vaccinated last December (the first time I interviewed Alain), “I’ve been impatient,” Alain said. “I really wanted to get mine.” Now he is finally on his way to joining the adults. When he heard on Tuesday that his shot was imminent, he let out a scream of joy, at “a pitch I have never heard him use before,” his mother, Kristen, told me.

There’s an air of cheer among the grown-ups as well. “It’s cause for celebration,” says Angie Kell, who lives in Utah with her spouse and their soon-to-be-vaccinated 6-year-old son, Beck. Their family, like many others, has been reining in their behavior for months to accommodate their still-vulnerable kid, unable to enjoy the full docket of post-inoculation liberties that so many have. Once Beck is vaccinated, though, they can leave mixed-immunity limbo: “We might have an opportunity to live our lives,” Kell told me.

The past year has been trying for young children, a massive test of patience—not always a kid’s strongest skill. And there’s yet another immediate hurdle to clear: the plodding accumulation of immunological defense. Alain has another 15 days to go until his second dose; after that, it’ll be two more weeks before he reaches a truly excellent level of protection. Only then, on December 7, will he count as fully vaccinated by CDC standards and be able to start adopting the behavioral changes the agency has green-lit. In the intervening weeks, he and the many other 5-to-11-year-olds in his position will remain in a holding pattern. Their wait isn’t over yet.

The timing of this semi-immune stretch might feel particularly frustrating, especially with the winter holidays approaching: At this point, essentially no young kids are slated to be fully vaccinated by Thanksgiving or Hanukkah, except the ones who were enrolled in clinical trials. One shot can offer a level of protection, but experts advise waiting to change behavior for a reason—the extra safeguards that set in about two weeks after the second shot really are that much better, and absolutely worth sitting tight for.

“It takes time for immune cells to get into a position where they’re ready to pounce,” Gigi Gronvall, a senior scholar at the Johns Hopkins Center for Health Security, told me. COVID-19 vaccines teach immune cells to thwart the coronavirus, a process that, like most good boot camps, takes many days to unfold. The second shot is essential to clinch the lesson in the body’s memory, encouraging cells to take the threat more seriously for longer. Immune cells also improve upon themselves over time—the more, the better in these early stages. Gronvall’s own 11-year-old son is also about to get his first shot, and she doesn’t want to risk stumbling so close to the finish line. “I can’t know exactly what his immune system is going to do” after the first dose alone, she said.

Evidence from Pfizer’s original clinical trial, conducted only in adults, hinted that a first, decent defensive bump takes hold after the first shot. Kit Longley, Pfizer’s senior manager of science media relations, pointed to those data when I asked how kids at various points along the vaccination timeline should be approaching behavioral change. “Protection in the vaccinated cohort begins to separate from the placebo arm as early as 12 to 14 days after the first dose,” he told me.

The adult clinical-trial data were collected last year, though, long before the rise of the Delta variant. A more recent study, conducted in the United Kingdom, showed that one dose of Pfizer reduced the risk of symptomatic COVID-19 by only 35.6 percent when the cause was Delta, and by only 47.5 percent with Alpha. (And remember that those numbers apply best on a population scale—not for a single, individual child.) After adding a second dose, though, effectiveness rocketed up to about 90 or 95 percent against either variant. “You really need two doses for adequate, good protection,” Samuel Dominguez, a pediatric-infectious-disease specialist at Children’s Hospital Colorado, told me.

Immunity is so far looking strong in young kids: In a recent trial of thousands of children ages 5 to 11, Pfizer’s vaccine was more than 90 percent effective at blocking symptomatic cases of COVID-19, including ones caused by Delta. Longley said Pfizer expects that the timing of protection will be similar between children and adults—a first dose should lower everyone’s risk to some degree. But the company’s pediatric trial picked up only a few COVID-19 casesnone of them occurred until about three weeks after the first dose was given, or later. So it’s hard to say anything definitive about when “enough” immunity really kicks in for kids.

Some parents are counting on a level of early protection from one shot, including my cousin Joanne Sy, whose 8-year-old son, Jonah, received his first injection on Friday. “He will have good immunity after one dose,” she told me, hopefully enough to guard him on a trip they’re taking to New York for Thanksgiving two weeks from now. “We’re still going to be cautious,” Sy told me: They’ll be watching the Macy’s Thanksgiving Day Parade from a hotel room rather than the streets, and wearing masks, at least on the plane. “But we just need to move forward.”

The calculus is playing out differently for Christy Robinson of Arlington, Virginia, who will again be “hunkering down” with her husband and two daughters, June and Iris, 7 and 5, respectively, this Thanksgiving. The kids got their first Pfizer shot on Saturday, setting their household up for full, full vaccination by mid-December, just in time to hold an indoor gathering with their aunts, uncles, and cousins for Christmas. (Some quick arithmetic: To be fully vaccinated by December 25, a kid would need their first dose by November 20.) June’s also eager to “see my friends inside, because it’s cold outside,” she told me—plus go to movie theaters, and Build-A-Bear, and a trampoline park, and IHOP, and the nail salon.

By the end of this conversation, Robinson looked amused and maybe a little regretful that my question had prompted such an extravagant list. As their mother, she’s especially excited for the possibility of no longer having to quarantine her daughters after viral exposures at school. Heftier decisions are ahead too. She and her husband are still weighing whether to bring their daughters into closer, more frequent indoor contact with their grandparents, who are vaccinated but could still get seriously sick if someone ferries the virus into their midst.

And that risk—of transmitting the virus—is worth keeping in mind, with so much SARS-CoV-2 “still circulating around,” cautions Tina Tan, a pediatrician and infectious-disease specialist at Northwestern University. Immunized people are at much lower risk of picking up the virus and passing it on. There still aren’t enough of them, though, to reliably tamp down spread; uptake of shots among young kids, too, is expected to be sluggish in the months to come. Even fully vaccinated families won’t be totally in the clear while our collective defenses remain weak.

That doesn’t mean Thanksgiving has to be a bust—or even a repeat of 2020, before the vaccines rolled out. The Bells will be cautiously gathering with a few loved ones; all the adults in attendance will be immunized and everyone will get tested beforehand. “Then they can come inside the house, mask off,” Taison Bell, Alain’s father, told me. None of those measures is completely reliable on its own; together, though, they’ll hopefully keep the virus out.

The road ahead might feel a little bumpy for Alain, who’s celebrating his 8th birthday at the end of November, a few days after his second shot. (He’s getting the gift of immunity this year, his father joked.) The Bells will do something special “around when he hits full vaccination,” Kristen said, “with something Alain hasn’t gotten to do in the last two years.” But Alain, who has asthma, which can make COVID-19 worse, knows that his own injections won’t wipe the slate clean for him, or those around him. Some people in his neighborhood have caught the virus even after getting vaccinated, and he understands that he could too.

Alain will keep masking, and treading carefully at school, and even a bit at home. His 3-year-old sister, Ruby, hasn’t yet been able to get a shot. (I asked her how she felt about Alain’s vaccine; she responded, almost imperceptibly, “Jealous.”) Until another regulatory green light comes, she will still be waiting, which means that her family will be too.

What to Know About the New Delta Sublineage

https://www.medpagetoday.com/special-reports/exclusives/95166?fbclid=IwAR2R-mSr-LHmqBo4mnO8HL542LlFsF1vi38PiW8mrohiYNjPu-O55qQk33c

As the now ubiquitous Delta variant continues to mutate, it’s spawned a new descendant that’s spread in the U.K. and made its way to the U.S.

The Delta sublineage, known as AY.4.2, is characterized by two “S-gene mutations” on A222V and Y145H, both located on the gene that encodes the spike glycoprotein of SARS-CoV-2.

CDC Director Rochelle Walensky, MD, acknowledged during the White House’s latest COVID-19 Response Team press briefing that the AY.4.2 sublineage has been identified “on occasion” in the U.S. without increased frequency or clustering to date.

Since August, AY.4.2 with these mutations has appeared in a total of three cases in the U.S.: in California, North Carolina, and Washington, D.C., according to Outbreak.info, which collects COVID-19 sequencing data from GISAID, a global genomic data-sharing initiative.

“At this time, there is no evidence that the sub-lineage AY.4.2 impacts the effectiveness of our current vaccines or therapeutics, and we will continue to follow up,” Walensky said.

Experts think the new Delta sublineage is slightly more transmissible, but say it’s likely less worrisome than its predecessor Alpha or Delta variants, which made bigger jumps in transmissibility. There’s a level of uncertainty over its exact advantage in spreading, however.

“There was a bit of a hope that Delta had, ideally, reached a kind of bound in transmissivity, so that will be a bit of a disappointment,” said Francois Balloux, PhD, computational biologist at University College London and director of the UCL Genetics Institute, in an interview.

Balloux predicted that at some point, almost everyone will be exposed to the “already so bloody transmissible” Delta variant, which makes up around 80% of sequenced cases in the U.K. He said AY.4.2 could be up to 15% more transmissible.

A lower estimate comes from Christina Pagel, PhD, the director of University College of London’s Clinical Operational Research Unit. On Twitter, she said that AY.4.2 could be up to 10% more transmissible: “We don’t know if it’s (a bit) more transmissible than other Delta strains *or* if it just got caught up in some superspreader events that seeded it.” That is, a large gathering of people could have amplified the effect of a strain that wasn’t intrinsically better at spreading.

“No reason to think it’s more immune evasive & might well be nothing. Something to keep an eye on but not panic over,” Pagel added.

The CDC lists AY.1 and AY.2 in its COVID Data tracker, and AY lineages generally under its “Variants of Concern” classification, but does not list AY.4 or AY.4.2 specifically. Balloux said that in the U.K., unlike the U.S., the genetic sequencing effort is nationally centralized. This makes it easier to track variants more quickly and accurately.

AY.4.2 was first spotted this spring in the U.K., where it represents 14,247 cases for a cumulative prevalence of 1% there at the time of publication, according to Outbreak.info.

The U.K. Health Security Agency reported on October 15 that AY.4.2 “is currently increasing in frequency” and that it made up 6% of the sequences analyzed. Balloux estimated that a more up-to-date number would be 7% to 8% because of a week-long lag in sequencing.

Notably, AY.4.2 spreads despite being characterized by S-gene mutations that are not known to make the virus intrinsically more transmissible. “Fundamentally, these are two very boring mutations,” Balloux said.

He clarified that this strain of SARS-CoV-2 is not “Delta plus” because it lacks a different mutation that defined that sublineage.

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