JMIR Publications

ABSTRACT

Background:

On April 13, 2021 the Centers for Disease Control and Prevention (CDC) and Food and Drug Administration recommended a pause in use of the Johnson & Johnson (J&J)-Janssen COVID-19 vaccine after reports of a rare blood clot in vaccinated individuals. Following this decision, the CDC posted a public statement on their website describing the rationale for the pause and recommendations for individuals who had received the vaccine.

Objective:

We evaluated understanding and impressions of the CDC’s crisis communication efforts about the pause in use.

Methods:

We administered an online survey to two cohorts of US adults recruited through Prolific between April 19-21, 2021 (cohort A, N = 271) and April 21-23, 2021 (cohort B, N = 286). Both cohorts were assembled using convenience sampling of unvaccinated adults; the first cohort was further restricted to individuals who expressed neutral or negative sentiments about COVID-19 vaccines. Participants read the CDC statement and answered 7 comprehension questions about the passage, as well as counterfactual questions about their trust in COVID-19 vaccines before and after the pause. Participants were also asked to guess the number of cases that led to the pause.

Results:

Across both cohorts, we found that understanding of the statement was negatively associated with self-reported vaccine hesitancy (odds ratio [OR], 0.61; 95% CI, 0.45-0.82; P = .001) and cohort B (OR, 0.48; 95% CI, 0.31-0.74; P = .001). In response to a counterfactual question, 127 (46.9%) participants in cohort A and 139 (48.6%) participants in cohort B indicated that the pause reduced their confidence in the safety of the J&J-Janssen vaccine. A majority of participants reported no change in their confidence in the safety of COVID-19 vaccines in general (182 [67.2%] for cohort A, 194 [67.8%] for cohort B). When asked to guess the specific number of affected individuals, 188 (69.4%) respondents in cohort A and 133 (46.5%) respondents in cohort B estimated 100 or more cases, at least an order of magnitude higher than the actual value.

Conclusions:

These results identify substantial gaps in understanding of the CDC’s public communications about the pause in use of the J&J-Janssen vaccine and suggest actionable strategies, including provision of quantitative and contextual information, for improved risk communication about COVID-19 vaccination.