The World Health Organization (WHO) has named vaccine hesitancy — the reluctance or refusal to vaccinate despite the availability of vaccines — as one of the top 10 threats to global health. Online misinformation may compound the problem. Yet despite this risk, little research attention has been paid to understanding how individuals seek vaccine information online and evaluate its trustworthiness.

Associate Professor Ayelet Baram-Tsabari and Dr. Aviv J. Sharon of the Technion Faculty of Education in Science and Technology, together with Dr. Elad Yom-Tov, a visiting scientist at the Technion Faculty of Industrial Engineering and Management, found that internet users tend to consider information that encourages vaccination as more trustworthy than information that discourages vaccination. This is less true for people who are hesitant about vaccines.

On average, the trustworthiness ratings of vaccine-hesitant people are more affected by the length of the text provided, suggesting a preference for detailed explanations. Furthermore, across the board, answers provided by health professionals were viewed as more trustworthy than those supplied by parents, which, in turn, were more likely to be perceived as trustworthy than answers that did not mention the writer’s expertise or parenthood status.

Headshot of Professor Ayelet Baram-Tsabari holding a publication.

The findings are based on 694 participants from the U.S. who rated 600 answers to vaccine-related questions retrieved from “Yahoo Answers.” They then rated the trustworthiness of the person who wrote the answer, as they perceived it, and completed a questionnaire concerning their own vaccine hesitancy. The researchers conducted a statistical analysis of the results to find which characteristics of the answers and the raters best predicted the trustworthiness ratings.

The study’s findings indicate that, despite the proliferation of anti-vaccine messages online, there is still a great deal of public trust in the knowledge provided by mainstream science and medicine. The findings of the study also suggest that expert outreach in online environments may be an effective intervention to address vaccine hesitancy.