Again pointing to plummeting COVID-19 case numbers among skilled nursing facility residents and staff—who were among the hardest hit in the early days of the pandemic and then were the first to get vaccinated—Los Angeles County health officials said the facilities are a case study on the effectiveness of the inoculations.

“Where we see high rates of vaccination, we are seeing transmission of COVID-19 plummet,” county Public Health Director Barbara Ferrer said in a statement this week. “Each person that is vaccinated has the best protection against COVID-19.

According to the Department of Public Health, 83% of skilled nursing facility residents and staff have received at least one dose of vaccine, and the vast majority of them have received both doses. During the week of April17, nearly 45,000 COVID tests were performed among all staff and residents at such facilities, with only about two dozen positive results.

That compares to more than 2,500 positive tests among nursing facility residents and staff the last week of December.

In Long Beach, between Dec. 1 and Dec. 30, the city reported 786 new cases of COVID-19 among people living in long-term care settings. After these facilities received access to the vaccine, that number ebbed dramatically. From Feb. 1 to March 1, just 123 new cases of the virus were reported.