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.