With flu season upon us, there is also the perennial discussion around if the flu vaccine itself can make you sick. It’s a highly charged debate, so we’d like to go straight to what we believe is the most authoritative source out there, the US’s Center for Disease Control.
And according to the CDC, the vaccine cannot make you sick, primarily because all of the viruses in the shot itself are “dead.” Furthermore, the vaccine manufacturers test batches to make sure the viruses are killed.
Studies have tested this theory and found that in a blind-test, where some people receive a flu shot and others get a placebo shot of salt water, there are no discernible differences in terms of getting the flu.
That said, some people do experience flu-like symptoms after receiving the shot. Yet this does mean they got the flu from the vaccine. The CDC offers up three possible scenarios for this occurrence.
One, the individual may have simply been exposed to the virus before the shot. Second, their post-vaccine illness may not, in fact, be the influenza virus, but rather another flu-like symptom. And third, not all influenza viruses are included in the vaccine; in other words, the shot isn’t foolproof, and people – albeit a small percentage – may get flu-like symptoms anyway.