Social network risk factors and COVID-19 vaccination: A cross-sectional survey study

Background: Social networks have an important impact on our health behaviours, including vaccination. People's vaccination beliefs tend to mirror those of their social network. As social networks are homogenous in many ways, we sought to determine in the context of COVID-19 which factors were most predictive of belonging to a mostly vaccinated or unvaccinated social group. Methods: We conducted a cross-sectional survey among Canadian residents in November and December 2021. Participants were asked about the vaccination status of their social networks their beliefs relating to COVID-19, and various sociodemographic factors. Respondents were split into three groups based on social network vaccination: low-, medium-, and high-risk. Chi-squared tests tested associations between factors and risk groups, and an ordinal logistic model was created to determine their direction and strength. Results: Most respondents (81.1 %) were classified as low risk (i.e., a mostly vaccinated social network) and few respondents (3.7 %) were classified as high-risk (i.e., an unvaccinated social group). Both the chi-square test (29.2 % difference between the low- and high- risk groups [1.8 % vs. 31.0 %], p < 0.001) and the ordinal logistic model (odds ratio between the low- and high-risk groups: 14.45, p < 0.01) found that respondents' perceptions of COVID-19 as a "not at all serious" risk to Canadians was the most powerful predictor of belonging to a predominantly unvaccinated social circle. The model also found that those in mostly unvaccinated social circles also more often reported severe COVID-19 symptoms (odds ratio between the low- and high-risk groups: 2.26, p < 0.05). Conclusion: Perception of COVID-19 as a threat to others may signal communities with lower vaccination coverage and higher risk of severe outcomes. This may have implications for strategies to improve public outreach, messaging, and planning for downstream consequences of low intervention uptake.