Study finds that correcting myths about the flu vaccine may not be effective in promoting immunisation

The study, which was co-authored by Brendan Nyhan, an assistant professor of government at Dartmouth College, USA and Jason Reifler, a senior lecturer of politics at the University of Exeter, found that debunking the myth that the seasonal influenza vaccine can give you the flu actually reduced intent to vaccinate among people who are most concerned about vaccine side effects.

The study was conducted with a nationally representative sample of adults in the U.S. collected as part of the 2012 Cooperative Congressional Election Survey. Respondents were randomly assigned to one of three conditions: a control condition in which no additional information about the flu or flu vaccines; a danger condition that presented information about the health risks posed by the flu; and a correction condition that informed respondents that they cannot contract the flu from the flu shot or live virus nasal spray. Both interventions were adapted nearly verbatim from Centers for Disease Control and Prevention materials. The researchers then compared the beliefs and intended behaviours of respondents after exposure to these messages.

The following is an overview of the study’s results:

• More than four in ten Americans (43%) endorsed the myth that the flu vaccine can give you the flu, saying it is either “somewhat” or “very accurate.”
• Respondents who received corrective information that the flu vaccine cannot give you the flu were less likely to report believing in this misperception or to say that the flu vaccine is unsafe.
• However, providing this corrective information also reduced the self-reported likelihood of getting a flu vaccine among respondents with high levels of concern about vaccine side effects. This information had no significant effect on intention to vaccinate among respondents with low concern about side effects.
• Providing information about the dangers of the flu had no effect on respondent beliefs about vaccine safety or their self-reported intention to vaccinate.

“Telling people they cannot contract the flu from the influenza vaccine decreases agreement with that myth,” Dr Reifler said. “But among those who are already skeptical of vaccines, this message seems to prompt counter-arguing and fears about other side effects, decreasing their intention to vaccinate. We believe this finding raises important questions for the N.H.S. and other agencies trying to promote immunization.” 

The study’s results are consistent with other findings by Nyhan and Reifler, which indicate that corrections of misperceptions about controversial issues may have unexpected or counterproductive results, including a previous study of the effects of correcting misperceptions about the measles, mumps, and rubella (MMR) vaccine.