P-281 Covid-19 Vaccination Coverage by Company Size in Japan: A Cohort Study

Introduction Various individual and contextual factors influence vaccination coverage. We investigated the relationship between company size and coverage of COVID-19 vaccination in Japan where workplace vaccination programs were implemented mainly at large companies. Methods We conducted an internet-based prospective cohort study from December 2020 (baseline) to December 2021. We finally analyzed the data from 15,829 participants. At baseline, the participants were asked about the size of the company they worked for, and at follow-up, they were asked about the month in which they received their second COVID-19 vaccine dose and the availability of a company-arranged vaccination opportunity. Results In September (midpoint) and December (final point) in 2021, the odds of receiving a second COVID-19 vaccine dose were significantly lower for small-company and self-employed workers than for large-company employees. This difference decreased after adjusting for socioeconomic factors, and it disappeared for only small-company employees when additionally adjusting for the availability of a company-arranged vaccination opportunity. The odds ratios for self-employed workers (only 1 employee) compared to large-company employees remained significant at 0.84 and 0.65 in September and December, respectively. Discussion Differences in COVID-19 vaccine coverage were observed depending on the size of the company. The differences can be explained by various demographic factors and workplace vaccination. However, they could not explain the vaccination coverage of self-employed workers. Conclusion The low vaccination rates of the self-employed may be due to the employment status itself. It will be necessary to enhance support of vaccination for this population in the event of future infectious disease outbreaks.