In another falsehood pushed by antivaccine advocates, there has been an erroneous claim on the internet that the flu vaccine has somehow “caused” the current severe influenza season. The claim implies that a mutation that occurred during the standard vaccine production in eggs directly caused the flu.

As has happened before, the target H3N2 strain in the vaccine antigenically drifted during production, giving the seasonal shot an efficacy of only 25%. Of course, the vaccine does not transmit flu; it is made of killed or attenuated virus designed to stimulate immune response.

The claim that the seasonal vaccine somehow causes the flu has been a persistent myth over the years, even among some healthcare workers. Part of this may stem from people who were already exposed to flu prior to being vaccinated, and then go on to develop symptoms in the week or so it takes to build up the immune response.

A recently published survey1 of healthcare workers found those who did not get the flu shot reported fear of the vaccine’s adverse effects (31%), doubts about its efficacy (29%), concerns about its safety (22%), and lack of adequate knowledge about vaccination (16%). In contrast, those vaccinated said immunization would give them partial protection against the flu (75%), reduce workforce loss (49%), and reduce deaths and severe conditions like pneumonia (43%).

It’s not just flu. The anti-vaccine movement has resulted in the reintroduction of virtually eradicated childhood diseases like the measles. Though there are many false concerns, a common fear is that the measles-mumps-rubella vaccine causes autism. Another recurrent claim is that the pediatric schedule of shots harms children due to the number of immunizations in the early years of development. Both of these myths have been thoroughly debunked, but it is difficult to persuade those suspicious of science with additional science.

In a fascinating study of the roots of psychological attitudes, researchers report that people who are against vaccinations are more likely to believe in conspiracy theories.

“Many intervention programs work from a deficit model of science communication, presuming that vaccination skeptics lack the ability to access or understand evidence,” the researchers report.2 “However, interventions focusing on evidence and the debunking of vaccine-related myths have proven to be either nonproductive or counterproductive.”

They examined the psychological factors behind this impasse, administering a questionnaire to more than 5,000 people in 24 countries. Across this dispersed global population, antivaccination attitudes were consistently highest among those who favored conspiratorial thinking. Those against vaccines also scored high in measures of a strong reaction to perceived infringements on individual freedom.

Instead of assailing these people with more science, the authors suggest a “jiu jitsu” approach of trying to align science communication with their “underlying fears, ideologies, and identities, thus reducing people’s motivation to reject the science.”

Ironically, they seem to conclude that it may be helpful to hint that the negative views of vaccines may be the result of a conspiracy.

“It is counterproductive to try to reduce people’s conspiratorial thinking — and there is no evidence that this is feasible,” the authors conclude. “Rather, one should work with people’s underlying worldviews to acknowledge the possibility of conspiracies, but to show how vested interests can conspire to obscure the benefits of vaccination and to exaggerate the dangers.”


1. Çiftci F, Sen F, Demir E, et al. Beliefs, Attitudes, and Activities of Healthcare Personnel About Influenza and Pneumococcal Vaccines. Hum Vaccin Immunother 2018;14(1):111-117.

2. Hornsey, M J, Harris, E A, Fielding, K S. The Psychological Roots of AntiVaccination Attitudes: A 24-Nation Investigation. Health Psychology. 1 Feb 2018. Advance online publication.