Three years ago, STAT laid out some of the questions surrounding flu vaccination in an article you can find here. Lots of flu vaccine studies have been published in the interval — clearing up some of the questions we raised, adding to the confusion with others.
Is it too soon to get your flu shot?
It’s now pretty clear that “intra-season waning” — the erosion of protection within a season — does occur. A study from the Centers for Disease Control and Prevention published in 2017 estimated the decline at about 7% a month from the time of vaccination.
Can repeated vaccination actually backfire?
There’s been a growing belief that getting a flu shot year after year can impede the immune system’s ability to generate a strong response to the vaccine.
It’s not thought that this phenomenon happens every year. But in some years when the viruses in the vaccine haven’t been updated but the viruses that are circulating are different from the vaccine version, people who have been repeatedly vaccinated may end up being less well protected. Influenza researchers call this “negative interference.”
Read full, original post: An updated guide to the changing science of flu shots