Highlighting Consensus Among Medical Scientists Increases Public Support for Vaccines

Evidence From a Randomized Experiment

Sander L. van der Linden; Chris E. Clarke; Edward W. Maibach


BMC Public Health. 2015;15(1207) 

In This Article


While public concern over (childhood) vaccines is growing,[5–7] recent attempts to communicate the health benefits of vaccines have failed to correct existing misperceptions and harness public support for the issue.[9–13] In contrast, our research shows that highlighting the degree of medical consensus increases perceived scientific agreement, which acts as a consequential "gateway" belief by promoting favorable public attitudes toward vaccination as well as by reducing perceived risk and belief in the (long discredited) autism-vaccine link. One plausible explanation for these promising results is that emphasizing consensus mitigates vaccine safety concerns in a way that does not require repeating a misinformation "myth" (e.g., mentioning a link between vaccines and autism). Research in cognitive psychology has shown that people are more likely to remember sticky "myths" than their "corrections" as revising pre-existing beliefs in light of new facts demands more cognitive effort.[23] Thus, while repeating a myth may simply reinforce existing beliefs, "setting the record straight" by emphasizing the high degree of medical consensus on vaccine safety avoids this dilemma.[24] The current study has a number of limitations. Particularly, our findings rely on a relatively small and non-representative sample of the American public. Although it is certainly possible that the typically younger and higher educated Amazon Turk participants are more reactive to the treatment than the general population, findings of this study are very much consistent with the results of communicating scientific consensus in other risk contexts[13–18] and extend prior pro-vaccine messaging interventions[13,14] in a novel direction. In short, highlighting the (normative) consensus among medical scientists that vaccines are "safe" and that parents should be "required" to vaccinate their children is a promising public health communication strategy that may be able to protect current immunization rates from declining and limit the spread of otherwise preventable (life-threatening) diseases. Future research could extend these findings in several important ways. For example, the efficacy of medical consensus messaging could be assessed using (a) national samples of US adults, (b) among vaccine hesitant parents specifically and/or (c) in clinical field setting(s). One practical recommendation may include highlighting the degree of medical consensus about (childhood) vaccine safety in patient waiting rooms or in other clinical and public health settings (when appropriate).