With COVID garnering all of the recent press and everyone’s attention, it seems that we have lost track of an old enemy that I am concerned may be lurking in the background setting us up for a problematic autumn.

For the past 2 years, influenza has been all but absent.  There are many speculations as to why with some of the theories being:

1.       Increased social distancing and masking efforts along with hand hygiene behaviors that came with a higher alert for COVID.  Experts believe that these mitigation efforts may have helped curb influenza over the past 2 years.

2.       Stay-at-home orders and remote working/studying especially in classroom settings.  Some of the seasonality thought to be associated with influenza in the wintertime has been attributed to children going back to school in the fall.

3.       The concept of viral interference.  This idea is far from proven but some virologists believe that COVID may compete with influenza from taking hold in the upper respiratory tract where both infections want to get their start.

4.       Heightened mucosal immunity secondary to recent COVID infection may have helped our individual immune systems bolster a better attack against influenza when previously encountered.

Regardless of the cause for fewer influenza infections, the statistics are pretty evident that we have had a nonexistent/mild flu season for the past 2 years. Because of this, I have a significantly heightened concern for a very problematic influenza season during the 2022-2023 season. A severe influenza season could easily result in over 50,000 deaths over a 6-month timeframe. As a reference, this may exceed current COVID mortality rates. My concern is secondary to the following considerations:

1.       Australia (in the southern hemisphere) has their seasonal flu season prior to our seasonal flu season.  The data coming in from Australia shows a significantly higher rate of influenza A along with an earlier onset of their flu season.  This data would suggest that we may experience a higher flu prevalence in earlier months such as October and November rather than the typical December through March.

2.       COVID infection is fairly rampant right now.  This means that many people will likely have quite a bit of immunity built up against COVID going into the fall resulting in less COVID infections at that time.  If viral interference played a role previously inhibiting concomitant influenza infection while COVID was rampantly circulating amongst the community, we could then therefore expect influenza virus to take advantage of the newly uninhibited opportunity in our respective upper respiratory mucosa’s allowing it to compete freely without coronavirus interference.

3.       With our individual increasing immune status against COVID via vaccination and natural immunity from infection, guidance regarding masks and social distancing have (appropriately) been relaxed.  This will present an opportunity for our normal socialization to resume but along with that comes increased risk for community spread of viruses.

4.       Historically speaking, in the years following mild influenza seasons, we tend to have a more severe season.  This may be secondary to decreased immunity from natural infection in the prior years leading to more severe disease if infected with influenza.

After 2 very long years, I continue to have decreasing concern about ongoing COVID infection secondary to a progressively weakened virus, increased immunity through natural infection and vaccination, and effective antiviral therapies like Paxlovid. My concern going forward is less about COVID and more about influenza.

Flu vaccines are starting to roll out within the community, and if able, my suggestion would be to get vaccinated against influenza this year.  If you are someone that typically does not get a flu shot, this might be a good year to consider getting one.  It is thought that immunity obtained from influenza immunization weans at a rate of 10% per month and takes approximately 2 weeks from initial vaccination to bolster enough immunity to help if the virus is encountered.  Based on this information and the data from Australia suggesting an earlier onset flu season, I think that the ideal time to get vaccinated against influenza may be in late September through early October.

Hope it was helpful!

Dr. Opperman