Editor’s Note: This article – separating fact from fiction about the flu vaccine – separating fact from fiction – has been reblogged with permission from Tara Haelle’s Red Wine and Applesauce blog. Many thanks to Tara and a host of other people for creating this list.
Note from Tara Haell: This post is co-published with NPR’s health blog Shots. Check out the story for updated information about this year’s flu shot from a CDC medical officer.
Once again, flu season is upon us — and so are all the misconceptions, excuses and worries that have kept so many people away from getting their flu vaccines. Plenty of people are fully informed about the flu vaccine’s safety and effectiveness and simply choose not to get the vaccine, as is their right (as long as they don’t work in healthcare settings where it’s required). But many others may have skipped the shot because they’ve bought into one of the many myths about the vaccine that always circulating with the influenza virus itself. Or perhaps they’ve read something unsettling about the vaccine that has a kernel of truth in it, but which has been blown out of proportion or misrepresented.
Of all the vaccines out there, the flu vaccine is unique in several ways: it’s the only one the CDC recommends for the entire (eligible) population every year, it has the most variability (and nearly always the lowest percentages) in effectiveness, and it has more tall tales told about it than Paul Bunyan. Much of the debunking and explaining you’ll find here is essentially the same as in past years’ posts, but a couple misconceptions have been rearranged, and I spent a bit more time discussing the evidence about potentially lower effectiveness of the flu vaccine in people who had gotten it the previous year.
Finally, I called these items “concerns” instead of “myths” because several of the issues discussed here are not outright “myths.” That is, some of these concerns originated from factual situations, but the details got gnarled and twisted along the way, or else the fact itself doesn’t have the implications people may expect it does. “Concerns” therefore better captures that each of these items is a legitimate concern for many people but is something that simply requires explanation, whether that’s an outright debunking or simply context and clarification.
One thing that needs a bit of clarification is last year’s vaccine’s effectiveness, as I discuss in the NPR Shots blog post that accompanies this one. The overall flu vaccine effectiveness last year was an uninspiring 23%, low enough to legitimately make you wonder why you bothered if you got the vaccine. But as I explain at NPR based on an interview with CDC influenza medical officer Lisa Grohskopf, the overall effectiveness doesn’t capture the effectiveness of each strain within the vaccine.
A poor match with the H3N2 strain — which caused the most illness and the most serious cases — was responsible for the lion’s share of that low number. Meanwhile, the match between the vaccine strains and the virus strains for B viruses, which circulated the most toward the end of the season, was good enough that the vaccine was closer to 60% effectiveness for those strains. This year, changes to the H3N2 strain for the vaccine should boost the effectiveness and offer a better showing than last year’s lousy run, according to Grohskopf.
With that info out of the way, let’s get to the flu vaccine concerns, with two important notes. First, for those who prefer to do their own research, I’ve provided all my sources in the hyperlinks. More than half of these go directly to peer-reviewed research articles, and a fair number go to the Centers for Disease Control and Prevention or the World Health Organization.
Second, but very important: I am a science journalist but not a medical doctor or other health care professional. I’ve compiled research here to debunk common misconceptions and clarify common concerns about the flu vaccine. This post does not constitute a recommendation from me personally to each reader to get a flu vaccine. You should always consult a reliable, trusted medical professional with questions that pertain specifically to you. For the CDC recommendations on the 2015-2016 flu vaccines (including information on which vaccines pregnant women, the elderly and children under 2 should *not* get), please consult the CDC flu vaccine recommendations directly. There are indeed people who should *not* get the flu vaccine.
To make it easier to navigate, I’ve listed all 31 concerns at the top followed by the factual information below it. They hyperlinked facts will jump to that explanation. I use “flu shot” and “flu vaccine” interchangeably to refer to any type of flu vaccine, including the nasal vaccine.
Continue reading Separating fact from fiction about the flu vaccine – 2015