Short-term impact of nursing home SARS-CoV-2 vaccinations on new infections, hospitalizations, and deaths

Objective: To compare rates of incident SARS-CoV-2 infection and 30-day hospitalization or death among residents with confirmed infection in nursing homes with earlier versus later SARS-CoV-2 vaccine clinics.

Design: Matched pairs analysis of nursing homes that had their initial vaccine clinics between December 18, 2020, and January 2, 2021, versus between January 3, 2021, and January 18, 2021. Matched facilities had their initial vaccine clinics between 12 and 16 days apart.

Setting and participants: Two hundred and eighty nursing homes in 21 states owned and operated by the largest long-term care provider in the United States.

Measurements: Incident SARS-CoV-2 infections per 100 at-risk residents per week; hospital transfers and/or deaths per 100 residents with confirmed SARS-CoV-2 infection per day, averaged over a week.

Results: The early vaccinated group included 136 facilities with 12,157 residents; the late vaccinated group included 144 facilities with 13,221 residents. After 1 week, early vaccinated facilities had a predicted 2.5 fewer incident SARS-CoV-2 infections per 100 at-risk residents per week (95% CI: 1.2-4.0) compared with what would have been expected based on the experience of the late vaccinated facilities. The rates remained significantly lower for several weeks. Cumulatively over 5 weeks, the predicted reduction in new infections was 5.2 cases per 100 at-risk residents (95% CI: 3.2-7.3). By 5 to 8 weeks post-vaccine clinic, early vaccinated facilities had a predicted 1.1 to 3.8 fewer hospitalizations and/or deaths per 100 infected residents per day, averaged by week than expected based on late vaccinated facilities' experience for a cumulative on average difference of 5 events per 100 infected residents per day.

Conclusions: The SARS-CoV-2 vaccines seem to have accelerated the rate of decline of incident infections, morbidity, and mortality in this large multi-state nursing home population.