Getting a flu vaccine is like wearing underwear. Just because you did it last year, doesn’t mean you shouldn’t do it this year.
Also, similar to underwear, the protection offered by a flu vaccine does not last forever. While the duration of protection can vary significantly from person to person, in some cases, the protection may wear off in 6 months or so, which is still much longer than you should wear a pair of underwear. That’s one reason why you should get a flu vaccine every year, assuming that you are 6 months and older because you can read this and you don’t have a medical reason (e.g., life threatening allergy) to not get the vaccine.
Another reason is that strains of the flu virus are like reality television stars. Different ones come and go from year to year. Therefore, the strains in a flu vaccine and thus the strains that you end up being protected against vary from year to year.
And if you are worried that getting the flu vaccine every year will somehow reduce your immunity against the flu, look at the study just published in JAMA. In fact, don’t just look at it, read it. For the study, a research team recruited kids who had visited outpatient clinics at Baylor Scott & White Health (Temple, Texas), the Marshfield Clinic Research Institute (Marshfield, Wisconsin), the Vanderbilt University Medical Center (Nashville, Tennessee), and Wake Forest School of Medicine (Winston-Salem, North Carolina) during the 2013-2014, 2014-2015, and 2015-2016 flu seasons. In order to qualify for the study, a kid had to have a fever and an acute respiratory illness and be real kids (ages 2 to 17 years) instead of just really immature adults. The research team ended up enrolling 3369 children in the study. Each kid received a flu test. The researchers checked whether each kid had received the flu vaccine the prior year. This allowed the researchers to divide the kids into 4 groups, based on whether they had received the flu vaccine the enrollment year and the year prior:
- Received the vaccine both the enrollment year and the prior year.
- Received the vaccine just the enrollment year
- Received the vaccine only the prior year.
- Did not receive the vaccine either year
About 23% (or 772) of the kids ended up testing positive for influenza. Around half (or 1674) had received the flu vaccine. The kids could have received one of two different types of flu vaccine each year: the one with the live but weakened virus that is squirted up your nose and the one with the dead virus that is injected into your arm.
The researchers tried to estimate the effectiveness of the flu vaccine by comparing the percentage of people who ended up testing positive for influenza among those who got the vaccine versus those who did not get the vaccine during enrollment year. Of course, this is a somewhat indirect way to estimate the effectiveness of the flu vaccine. Plus, kids visiting a clinic for a fever and respiratory illness do not necessarily represent the general population.
Nonetheless, the study found no evidence that getting the vaccine the prior year reduced the effectiveness of the vaccine the subsequent year. In other words, based on the study results, getting the vaccine last year won’t make the vaccine less effective and you more likely to get the flu this year. In fact, the study results suggested that getting the vaccine the prior year may help further boost the vaccine’s protection against the certain types of influenza, the B types.
So, why not get the flu vaccine each and every year, as the Centers for Disease Control and Prevention (CDC) recommends? And change your underwear much, much more frequently. If you want to maximize your immunity against the flu, you have to get the vaccine each and every year. There is just no other scientifically proven way to substantially boost your immunity against this virus that could potentially kill you no matter how healthy you may be. Sure, keeping healthy by eating well and staying physically active can help to some degree. But a supplement, a particular food item, or magic potion will not offer you the same immunity against the flu that a vaccine can. Don’t listen to those selling supplements who are making claims of protection against the flu that have no real supporting scientific evidence. Like underwear that’s been on too long, a lot of the bogus flu protection claims out there can get pretty stinky.