Assessment of Communication Strategies for Mitigating COVID-19 Vaccine-Specific Hesitancy in Canada
Authors: Eric Merkley, Peter John Loewen
Journal: JAMA Network Open (2021)

<h3>Importance</h3> Ensuring widespread uptake of available COVID-19 vaccinations, each with different safety and efficacy profiles, is essential to combating the unfolding pandemic. <h3>Objective</h3> To test communication interventions that may encourage the uptake of less-preferred vaccines. <h3>Design, Setting, and Participants</h3> This online survey was conducted from March 24 to 30, 2021, using a nonprobability convenience sample of Canadian citizens aged 18 years or older, with quota sampling to match 2016 Canadian Census benchmarks on age, gender, region, and language. Respondents completed a 2-by-2-by-2 factorial experiment with random assignment of brand (AstraZeneca or Johnson &amp; Johnson), information about the vaccine's effectiveness against symptomatic infection (yes or no), and information about the vaccine's effectiveness at preventing death from COVID-19 (yes or no) before being asked about their willingness to receive their assigned vaccine and their beliefs about its effectiveness. <h3>Exposures</h3> Respondents were randomly assigned a vaccine brand (AstraZeneca or Johnson &amp; Johnson) and information about the vaccine's effectiveness against symptomatic COVID-19 infection (yes or no) and at preventing death from COVID-19 (yes or no). <h3>Main Outcomes and Measures</h3> Respondents' self-reported likelihood of taking their assigned vaccine if offered (response categories: very likely, somewhat likely, not very likely, or not at all likely, scaled 0-1) and their beliefs about their assigned vaccine's effectiveness (response categories: very effective, somewhat effective, not very effective, or not at all effective, scaled 0-1) were measured. <h3>Results</h3> A total of 2556 Canadian adults responded to the survey (median [IQR] age, 50 [34-63] years; 1339 women [52%]). The self-reported likelihood of taking an assigned AstraZeneca or Johnson &amp; Johnson vaccine was higher for respondents given information about their assigned vaccine's effectiveness at preventing death from COVID-19 (<i>b</i>, 0.04; 95% CI, 0.01 to 0.06) and lower among those given information about its overall effectiveness at preventing symptomatic transmission (<i>b</i>, −0.03; 95% CI, −0.05 to 0.00), compared with those who were not given the information. Perceived effectiveness was also higher among those given information about their assigned vaccine's effectiveness at preventing death from COVID-19 (<i>b</i>, 0.03; 95% CI, 0.01 to 0.05) and lower among those given information about their assigned vaccine's overall efficacy at preventing symptomatic infection (<i>b</i>, −0.05; 95% CI, −0.08 to −0.03), compared with those who were not given this information. The interaction between these treatments was neither substantively nor statistically significant. <h3>Conclusions and Relevance</h3> These findings suggest that providing information on the effectiveness of less-preferred vaccines at preventing death from COVID-19 is associated with more confidence in their effectiveness and less vaccine-specific hesitancy. These results can inform public health communication strategies to reduce hesitancy toward specific COVID-19 vaccines.