COVID-19 cases and mortality in long-term care facilities have decreased significantly in the months since residents and staff members were prioritized for vaccination. Nationwide, however, vaccination rates among nursing home staff members overall fall below the general population, and where those vaccinations lag, COVID-19 outbreaks may follow, according to experts who spoke with  ABC News.

The media outlet cited an outbreak among 28 residents in two of Rochester Regional Health’s skilled nursing facilities last month. Fewer than 45% of the networks’ staff was fully vaccinated. The organization operates seven skilled nursing facilities in upstate New York, according to its website

In the case of an outbreak in a Kentucky nursing home in March, residents and staff who had received the shots were much less likely to become ill or to be hospitalized than the unvaccinated people who lived and worked on site, according to a Centers for Disease Control and Prevention report.

“The outbreaks showed not just the power of the vaccine, but also the risk of forgoing it,” authors Laura Romero and Meridith Deliso wrote.

According to the CDC, COVID-19-related nursing home deaths nationwide at the end of May, were down dramatically from numbers reported in January, before vaccinations in long-term care facilities began.

“It’s an important message that we need to keep sharing, that the vaccine is working, and it’s working among the most vulnerable patients,” Robert Mayo, M.D., chief medical officer of Rochester Regional Health, told ABC News.The list of long-term care providers requiring employees to be fully vaccinated against COVID-19 is growing. With updated guidance from the Equal Employment Opportunity Commission, it remains to be seen whether more nursing homes will follow suit. Employers can require workers to receive the COVID-19 vaccination, the EEOC determined, but some providers are struggling to determine what the law allows and what it requires.