Comparison of Covid-19 antibody status after vaccination between residents in long-term geriatric care and residents assisted-living facilities.

Objective: To compare 2 CoV-SARS-2 ('anti-s') antibody levels after vaccination between residents in long-term geriatric care (LTGC) and residents in assisted-living facilities who had received two doses of the BNT162b2 vaccine. SARS-CoV-2 serology was tested with Quant II IgG CoV-SARS-2. Blood samples were collected 3-4 months after administration of the second vaccine dose.
Results: Anti-s ≥ 50 AU/ml was found in 85.4% of 90 residents in LTGC (median 498 AU/ml) and 94.9% of 214 residents in assisted living (median 728 AU/ml). p = .006. Factors associated with anti-s < 300 AU/ml were multi-morbidity, diabetes mellitus and cancer.