The first concern is that immunity from influenza only lasts a year or two.  If far fewer people were exposed to the circulating influenza viruses in the past year, then the level of natural immunity in the population will be low.   Will this be like forest fires where if you suppress all the little fires when you finally get a forest fire it’s a monster?  We just don’t know.  It is unclear how people’s immune systems will respond when re-exposed to influenza.

 Secondly, the near absence of influenza is 2020-2021 impacted vaccine production for this season.  The Global Influenza Surveillance and Response System (GISRS) is a group of laboratories and public-health institutions in 123 countries that collect respiratory samples throughout the year.  They do gene sequencing of the influenza viruses to determine which ones are most prevalent.  In February, the WHO united experts to recommend which strains of flu should be targeted by the next influenza vaccine for the Northern hemisphere.  In February of 2021, these experts selected four viruses for this year’s vaccines.  Given that they had less information, it’s uncertain if they targeted the right viral strains.  

The third area of concern is the possibility of managing both a bad influenza outbreak and a COVID resurgence this winter.  This has produced a new term in medicine.   Instead of a pandemic we would have a “twin-demic.” The Academy of Medical Sciences in Britain report that being infected with influenza A makes people more susceptible to COVID-19.  There is increasing evidence that influenza and COVID-19 can coexist and that if you have both infections simultaneously COVID 19 is worse.   Also, anyone with even mild influenza will seek medical attention to get a COVID 19 test and this will tax the medical system.  

As a result of all these factors, this will be a unique winter of unknowns.  The best strategy of protection and prevention is simply to get vaccinated for both infections if approved by your healthcare provider.   Also, although social distancing rules are being loosened, you should continue to wash your hands, wear masks in public indoor spaces and socialize outdoors.

References:

1. Northern Exposure. The Economist. September 25, 2021.
2. Seasonal Influenza in adults: Transmission, clinical, manifestations, and complications. Raphael Dolin, MD. UpToDate. Nov.18,2020.