Influenza’s Unprecedented Low Profile During COVID-19 Pandemic Leaves Experts Wondering What This Flu Season Has in Store
Rita Rubin
Abstract
feared "twindemic"-an influenza epidemic wrapped in a COVID-19 pandemic-never materialized, much to the relief of critical care specialists and their hospitals' administrators.Instead, flu cases and deaths in the US and worldwide dropped to unprecedented lows, and influenza remained scarce this summer for the second consecutive flu season in the Southern Hemisphere.Between October 3, 2020, and July 24, 2021, of the 1.3 million specimens tested by clinical laboratories and reported to the US Centers for Disease Control and Prevention (CDC), 2136 were positive for influenza virus, and 748 deaths were coded as influenza, according to CDC data provided to JAMA.In a typical season, 75 to 150 children die of influenza in the US, pediatric infectious disease specialist Paul Offit, MD, director of the Vaccine Education Center at the Children's Hospital of Philadelphia, noted in an interview.Last flu season, he said, 1 child died.As in previous years, "it is likely that there were many more" flu deaths in the US, a CDC spokesman noted in an email.Not all flu deaths are reported to the CDC, and not all deaths due to flu-related complications are listed as such on death certificates.However, that doesn't explain the eyepopping differences between the 2020-2021 flu season and its predecessor.In the 2019-2020 season, more than 38 million people in the US became sick with influenza and nearly 22 000 of them died, the CDC estimates.Except for a few places, such as western Africa, "the flu was essentially nowhere" this past fall and winter, virologist Richard Webby, PhD, of St Jude Children's Research Hospital, 1 of 6 World Health Organization (WHO) Collaborating Centers for influenza, told JAMA in an interview.How more than a year with virtually no influenza bodes for the coming flu season is unknown, and potential scenarios range from a repeat of last season's numbers to an explosion in cases.Several what ifs will determine the upcoming season's magnitude: the COVID-19 pandemic'sseveritythisfallandwinter,theex-tenttowhichSARS-CoV-2mitigationmeasures continuetobeused,andhowwellvaccinesare matched to circulating influenza viruses.