Communications to Promote Interest and Confidence in COVID-19 Vaccines

Purpose Communicating about COVID-19 vaccine side effects and efficacy is crucial for promoting transparency and informed decision-making, but there is limited evidence on how to do so effectively. Design A within-subjects experiment. Setting Online survey from January 21 to February 6, 2021. Subjects 596 US Veterans and 447 non-Veterans. Intervention 5 messages about COVID-19 vaccine side effects and 4 messages about COVID-19 vaccine efficacy. Measures COVID-19 vaccine interest (1 = I definitely do NOT want the vaccine to 7 = I definitely WANT the vaccine with the midpoint 4 = Unsure). Confidence about COVID-19 vaccine efficacy (1= Not at all confident, 2 = Slightly confident, 3 = Somewhat confident, 4 = Moderately confident, 5 = Extremely confident). Results Compared to providing information about side effects alone (M = 5.62 [1.87]), messages with additional information on the benefits of vaccination (M = 5.77 [1.82], P < .001, d(z) = .25), reframing the likelihood of side effects (M = 5.74 [1.84], P < .001, d(z) = .23), and emphasizing that post-vaccine symptoms indicate the vaccine is working (M = 5.72 [1.84], P < .001, d(z) = .17) increased vaccine interest. Compared to a vaccine efficacy message containing verbal uncertainty and an efficacy range (M = 3.97 [1.25]), messages conveying verbal certainty with an efficacy range (M = 4.00 [1.24], P = .042, d(z)=.08), verbal uncertainty focused on the upper efficacy limit (M = 4.03 [1.26], P < .001, d(z) = .13), and communicating the point estimate with certainty (M = 4.02 [1.25], P < .001, d(z) = .11) increased confidence. Overall, Veteran respondents were more interested (M- Veterans = 5.87 [1.72] vs M- NonVeterans = 5.45 [2.00], P < .001, d = .22) and confident (M- Veterans = 4.13 [1.19] vs M- NonVeterans = 3.84 [1.32], P < .001, d = .23) about COVID-19 vaccines than non-Veterans. Conclusions These strategies can be implemented in large-scale communications (e.g., webpages, social media, and leaflets/posters) and can help guide healthcare professionals when discussing vaccinations in clinics to promote interest and confidence in COVID-19 vaccines.

Automated summary

This study investigates how to effectively communicate about the side effects and efficacy of COVID-19 vaccines. The findings suggest that providing information on the benefits of vaccination, reframing the likelihood of side effects, and emphasizing post-vaccine symptoms can increase vaccine interest. Using verbal certainty and an efficacy range in messages can also enhance confidence in vaccine efficacy. The study also reveals that Veterans show higher levels of interest and confidence in COVID-19 vaccines compared to non-Veterans.