Infectiology In Medical Personnel Of The Emerging Covid-19. Current Outbreak In US

 

Since the deployment of the messenger RNA (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in nursing homes nationwide starting in mid-December 2020, aggregate public data have shown decreases in the incidence of cases of SARS-CoV-2 infection and related deaths. However, there have been minimal individual-level data available for understanding vaccine effectiveness in nursing home residents, who were absent from the clinical trials and who often have reduced immune responses. Using electronic health record data from Genesis HealthCare, a large long-term care provider in the United States, we report the incidence of SARS-CoV-2 infection among vaccinated residents and unvaccinated residents of 280 nursing homes across 21 states.

 

From immunization records, we identified residents who had received at least one dose of mRNA vaccine as of February 15, 2021; those who had received both doses by February 15, 2021; and those who were present at their facility on the day of the first vaccination clinic but who were not vaccinated as of March 31, 2021. We identified incident SARS-CoV-2 infections through March 31, 2021, on the basis of polymerase-chain-reaction assay and antigen-test records. Residents were tested every 3 to 7 days when there were confirmed cases in their facility and were tested if they had any new symptoms or potential exposure.

 

The sample included 18,242 residents who received at least one dose of mRNA vaccine; 14,669 residents (80.4%) received the Pfizer–BioNTech vaccine, and 3573 (19.6%) received the Moderna vaccine. Of these 18,242 residents, 13,048 also received the second dose of vaccine. A total of 3990 residents were unvaccinated.