Doctors and scientists have been relieved that the dreaded “twindemic”—the usual winter spike of seasonal influenza superimposed on the COVID pandemic—did not materialize.
In fact, flu cases are at one of the lowest levels ever recorded, with just 155 flu-related hospitalizations this season (compared to over 490K in 2019). A new piece in the Atlantic looks at the long-term ramifications of a year without the flu.
Public health measures like masking and handwashing have surely lowered flu transmission, but scientists remain uncertain why flu cases have flatlined as COVID-19, which spreads via the same mechanisms, surged.
Children are a much greater vector for influenza, and reduced mingling in schools and childcare likely slowed spread. Perhaps the shutdown in travel slowed the viruses’ ability to hop a ride from continent to continent, and the cancellation of gatherings further dampened transmission.
Nor are scientists sure what to expect next year. Optimists hope that record-low levels of flu could take a strain out of circulation. But others warn that flu could return with a vengeance, as the virus continues to mutate while population immunity declines.
Researchers developing next year’s vaccines, meanwhile, face a lack of data on what strains and mutations to target—although many hope the mRNA technologies that proved effective for COVID will enable more agile flu vaccine development in the future.
Regardless, renewed vigilance in flu prevention and vaccination next fall will be essential, as a COVID-fatigued population will be inclined to breathe a sigh of relief as the current pandemic comes under control.