Winter is almost here, which means flu season is just around the corner. It also means that anti-flu vaccine misinformation will go viral again (pun intended). There are many common myths regarding the flu shot. Please see the Top 10 Myths about the flu vaccine, sickness, treatment and recovery fully addressed by Harvard Health.
Besides these common myths, there are posts that get shared over and over again through social media. A study published in the Proceedings of the National Academy of Sciences investigated how misinformation grows online. The so-called “echo chambers” allow people to expand and amplify their own biases without obstruction. So before this fake information gets reinforced further by repetitive transmission – particularly on Facebook – let’s review those that get shared the most.
FALSE. According to Steven Salzburg, a Johns Hopkins Professor, this report on flu vaccine is neither shocking nor correct. It talks about an article by Peter Doshi published in May 2013 in the British Medical Journal (BMJ). The importance of this feature was wildly exaggerated by natural news sites and anti-vaccine groups that quoted the publication in their own articles. The BMJ piece was neither a peer-reviewed study nor a research article but an opinion piece (and everyone is entitled to an opinion). This opinion piece was authored by an anthropologist who is neither a “Johns Hopkins scientist” nor a professional in the medical or biological fields. Thanks to Snopes.com and Skepticalraptor.com for the fact check. Here is the official response from Johns Hopkins University.
FALSE. The CDC did not issue an apology and state that the 2014-2015 flu vaccine did not work. On Dec. 3, 2014, the Centers for Disease Control (CDC) issued a health advisory to clinicians about the 2014-2015 flu season. The CDC press release stated that the H3N2 virus (only one of the three or four strains the vaccine was designed for) had mutated slightly, and protection for that one strain was reduced. Furthermore, the CDC explained to clinicians that the flu vaccine still provided some protection against drifted flu strains and that not all strains of flu had drifted. Even during flu seasons when the vaccine isn’t a perfect match, cross-protection against circulating flu strains results in fewer instances of severe reactions or deaths from the flu. Naturally, Natural News, the gold standard for fake science news and fear mongering, cherry-picked the CDC announcement and wrote on Facebook: “Really? CDC issues flu vaccine apology: this year’s vaccine doesn’t work!” Thanks to IFLScience.com and ScienceBasedMedicine.org for the fact check.
FALSE. There was one study (published in 2012) that suggested that the flu vaccine might make people more prone to infection of other respiratory infections. After the study was published, several experts looked into this issue further and performed additional studies to see whether the findings could be replicated. However, no other studies have found this effect. For example, this article published in 2013 in Clinical Infectious Diseases concluded that influenza vaccination is not associated with detection of non-influenza respiratory viruses. It is not clear why this finding was detected in one study, but the preponderance of evidence suggests that this is not a common or regular occurrence and that influenza vaccination does not, in fact, make people more susceptible to other respiratory infections.
FALSE. The authors in this small-scale study recently published in the journal Vaccine stress the important limitations of their work. Among them, in the authors’ own words:
“This interaction effect was not an a priori hypothesis; the results were generated in a post hoc analysis with small numbers of women in the various subgroups.”
The level of evidence of this study is considered low. The study included a small number of women in a subgroup, the “confidence intervals were wide” and this was a case-control study. It estimated an odds ratio of vaccination among women who had a miscarriage compared to those who did not. The study did not estimate risk of miscarriage after influenza vaccination, and the “cases were significantly older than controls.” Miscarriage becomes more common in women over 35 years old, which researchers even refer to as “advanced maternal age.” This recent study did not confirm a link but showed an association between flu vaccine and miscarriage in this small group of women. It is important to note that millions of flu vaccines have been given for decades, including to pregnant women, with a good safety record. Indeed, pregnant women are at high risk of serious flu complications ― they are recommended for influenza vaccination during any trimester of their pregnancy. The CDC, the American College of Obstetricians and Gynecologists, and the study authors all continue to recommend that pregnant women get a flu vaccine during any stage of pregnancy.
These are some of the most viral misinformation about flu vaccines that keep people from getting the flu shot, which unfortunately put them and others at high risk of contracting the influenza virus.