Coronavirus infections among both vaccinated and unvaccinated nursing home residents decreased significantly following vaccination clinics at their facilities, according to results of a newly published study in the New England Journal of Medicine.

Results suggest that having enough COVID-19 vaccine coverage in congregate settings, like nursing homes, appears to protect unvaccinated individuals, further promoting the benefits of vaccines, scientists said.

“Our observation of a reduced incidence of infection among unvaccinated residents suggests that robust vaccine coverage among residents and staff, together with the continued use of face masks and other infection-control measures, is likely to afford protection for small numbers of unvaccinated residents in congregate settings,” Brown University researchers wrote. 

“Still, the continued observation of incident cases after vaccination highlights the critical need for ongoing vaccination programs and surveillance testing in nursing homes to mitigate future outbreaks,” they concluded. 

The study used COVID-19 case data among vaccinated and unvaccinated residents at 280 nursing homes across 21 states. A total of 18,242 residents received at least one vaccine dose and of those, 13,048 also received a second vaccine dose. These were considered in juxtaposition to data from 3,990 unvaccinated residents.  

Testing information revealed that incidence of infections decreased over time among both groups. Only 822 cases, or 4.5%, were detected among residents with just one vaccine dose within 14 days of the first vaccine doses, and 250 cases (1.4%) were reported 15 to 28 days after the initial doses.  

Some 130 cases (1%) were reported among the fully vaccinated residents within 14 days after their second dose, while a fraction of that (38 cases) were found after the two-week period.

Among unvaccinated residents, cases decreased from 173 within 14 days of the first vaccination clinic at their facility to just 12 about 40 days after the clinic. 

The findings emphasized the “real-world effectiveness” of the COVID-19 vaccines in reducing the infections in the vulnerable nursing home population, researchers said.

The research team was led by Brown University’s investigator Elizabeth White, Ph.D., and also included long-term care researcher Vincent Mor, Ph.D.