Dr. Roach: For flu season, it’s still best to get vaccinated by October

Keith Roach
To Your Health

Dear Dr. Roach: Both my husband and I just had the flu. We initially suspected that it was COVID, but the tests were negative. My symptoms, especially cough and runny nose, hung on for over two weeks. I visited an urgent care clinic where I was told I most likely had the (seasonal) flu, and I was prescribed an inhaler as well as a cough suppressant. The physician indicated that they have seen a lot of flu cases this summer. I am thinking the rise is because of people wearing masks and staying home these past couple of years, which could thereby weaken our immune systems.

When I filled my prescriptions at the pharmacy, the pharmacist told me that they started flu vaccines in August. We typically get our seasonal flu vaccines in October to ensure its effectiveness through February and March. Considering these unusual times, would it make sense to get the vaccine earlier this year? My husband and I are over 65.

Dr. Keith Roach

— S.A.

Dear S.A.: I’m not sure you had the flu, although there are sporadic cases in the summer.

The World Health Organization recently announced the vaccine composition for the 2022-2023 flu season, with two influenza A viruses (H1N1 Victoria and H3N2 Darwin) and two influenza B viruses (B/Victoria and B/Yamagata). All the flu vaccines this year are quadrivalent, meaning they cover all four of the recommended strains. However, the timing is even more of a guess this year than ever.

Last year, at the office I practiced in New York, there were two peaks of influenza activity: one that began in November and peaked in mid-December, and then a second, larger peak in April and May (but with some activity lasting until June). This was similar in other parts of the country. This contrasts sharply to the previous year, when there was almost no flu activity (back when we were wearing masks and socially distancing very carefully). For most years, getting the vaccine in September or October is ideal, because the vaccine takes two weeks or so to become effective. The vaccine lasts roughly six months before the protective effect is lessened.

Because the flu season went on so long this year, people who got vaccinated early, such as in August, were potentially at higher risk toward the end of the second peak. For that reason, I don’t recommend getting the flu shot so early this year: September or October is still probably best. However, flu activity could start early, so finding out what’s happening in your local area from your local health department will help your doctor recommend the ideal time for you. I would really recommend getting it by the end of November, but it would still be beneficial later on, especially if the flu season lasts as long again.

As always, there are many flu vaccines to choose from, and it does not matter much which one you choose. People who are over 65, or who have weakened immune systems, should consider one of the high-dose or adjuvanted flu vaccines (Fluzone High-Dose, Flublok or Fluad), but I would still recommend getting a regular-dose vaccine if you can’t find one of these higher-potency vaccines at the time you want to get vaccinated.

Readers may email questions to ToYourGoodHealth@med.cornell.edu.