Abstract
Mass vaccination is effective in reducing SARS-CoV-2 infections among vaccinated individuals. However, it remains unclear how effectively COVID-19 vaccines prevent people from spreading the virus to their close contacts. Using nationwide administrative datasets on SARS-CoV-2 infections, vaccination records, demographics, and unique household IDs, we conducted an observational cohort study to estimate the direct and indirect effectiveness of mRNA-based COVID-19 vaccines in reducing infections among vaccinated healthcare workers and their unvaccinated household members. Our estimates for adults imply indirect effectiveness of 39.1% (95% CI: -7.1% to 65.3%) two weeks and 39.0% (95% CI: 18.9% to 54.0%) eight weeks after the second dose. We find that the indirect effect of mRNA-based COVID-19 vaccines within households is smaller for unvaccinated children than for adults and statistically insignificant. Here, we show that mRNA-based COVID-19 vaccines are associated with a reduction in SARS-CoV-2 infections not only among vaccinated individuals but also among unvaccinated adult household members in a real-world setting.
【초록키워드】 COVID-19 vaccine, vaccination, SARS-COV-2 infection, children, Infection, virus, healthcare worker, Effectiveness, dataset, estimate, SARS-CoV-2 infections, demographics, Observational cohort study, second dose, mass, vaccinated individuals, vaccinated individual, Prevent, effective, mRNA-based COVID-19 vaccine, conducted, eight, unique, reducing, reduction in, statistically, 【제목키워드】 healthcare worker, COVID-19 vaccination, mRNA-based,