What do People Consider “Trustworthy” Vaccine Information?

Vaccine misinformation is a worldwide concern, but little is known about its spread and adoption. How do people seek vaccine-related information and decide whether to trust it? This is very much an open question.

Using questions and answers retrieved from “Yahoo! Answers,” we explored how individuals seek vaccine-related information online and evaluate its trustworthiness.

Research Question

What factors are associated with the perceived trustworthiness of online content about vaccines?

  • Stance towards vaccines (”what is said”): Does it matter if the answer encourages or discourages vaccination?
  • Answerers’ identity (”who said it”): Does it matter if the answer is written by someone who identifies as a health professional, as someone who identifies as a parent, or as someone who does not identify as either?


We conducted an online experiment to find out what factors are associated with the perceived trustworthiness of answers in online Q&A plaforms.

Participants were shown authentic answers from a Q&A platform that:

(1) were either…

✅ pro-vaccination or

❌ anti-vaccination;

(2) and were written by…

🧑‍⚕️ people who identified as health professionals, or

👪 people who identified as parents, or

👤 by answerers who did not identify as either.

Participants were then asked to rate the trustworthiness of the answerers.

Next, they were asked answer a question that made sure they were paying attention, and indicate how much they agreed with four statements about vaccines (e.g., "Overall I think vaccines are safe").

Findings and Discussion

On average, the “who said it” factor was associated with the answers’ trustworthiness scores. However, the strength of the association had a lot to do with answer's stance towards vaccination: The “who said it” factor was more closely associated with the scores of pro-vaccine answers; by contrast, when it came to answers that discouraged vaccines, the “who said it” factor had a smaller effect.

It seems that when it comes to vaccines, on average, health professionals are considered more trustworthy than parents. Self-identifying as an expert has a small effect (compared to the answer's stance towards vaccines) but it still measurable, even among vaccine-hesitant raters.


By and large, internet users consider primarily "what is said" and (to a lesser extent) "who said it" when assessing online vaccine information.

Vaccine-hesitant internet users’ considerations seem to be more complex than those of other users, in this context. More research is needed to figure out how to better cater to this audience over the internet.


Figure 1. Epistemic trustworthiness ratings by answer's stance towards vaccination and answerer self-identification.

(a) Descriptive statistics of trustworthiness ratings for all raters, for vaccine-hesitant raters, and for vaccine-confident raters. Ratings are based on the mean of 14 questionnaire items on a 7-point Likert scale. Error bars denote the standard error of the mean.

(b) Moderation analyses predicting epistemic trustworthiness ratings. These analyses examine whether different variables predict trustworthiness ratings, and if so, to what extent, and whether the relationship between answerer self-identification and trustworthiness depends on the answer's stance towards vaccines. One moderation analysis was performed for all raters, and one analysis each for vaccine-hesitant raters and vaccine-confident raters. Each independent variable was attributed a standardized regression coefficient (beta coefficient), which describes the extent to which changes in that variable are related to changes in trustworthiness ratings, when holding all other variables constant, where changes in variables are measured in standard deviations.

One, two and three bullets (•, ••, •••) denote significance at the 0.05, 0.01 and 0.001 levels, respectively.

Note: The statistical analyses for this part of the project were conducted by a freelance statistical consultant, Dr. Amihai Rigbi. I designed the experiment, wrote up the findings and drew the figures.

Press Releases and Media Coverage

איך מעבירים מדע ברשת? - מכון דוידסון, 22.3.2020


Sharon, A. J., Yom-Tov, E., & Baram-Tsabari, A. (2020). Vaccine information seeking on social Q&A services. Vaccine, 38(12), 2691–2699. https://doi.org/10.1016/j.vaccine.2020.02.010