For a study, researchers sought to understand that infection control is a significant public health issue during COVID-19 epidemics in nursing homes. The antibody responses in nursing home residents before and after receiving the third (booster) dose of SARS-CoV-2 immunization haven’t been sufficiently studied. About 54 nursing home residents (mean age 83.8 years; 39 SARS-CoV-2 naive and 15 already infected) and 63 healthcare professionals made up the 117 participants in this study (mean age, 45.8 years; 32 SARS-CoV-2-naive and 31 previously infected). Using pre- (shortly and 6 months after the second dose) and post-booster vaccination samples, the anti-spike (receptor-binding domain [RBD]) and anti-nucleocapsid antibody responses to BNT162b2 mRNA vaccination and their related variables were assessed. About 6 months following the second therapy, the median anti-spike (RBD) IgG level in SARS-CoV-2-naive residents decreased at a pace of almost 90%, the quickest of the 4 groups. The median rise before and after the third dosage in SARS-CoV-2-naive inhabitants was significantly larger than that in SARS-CoV-2-naive healthcare workers (64.1- vs. 37.0-fold, P=0.003), with the maximum level among the groups. The IgG ratio of SARS-CoV-2-uninfected residents to medical professionals increased from one-fifth (20%) to one-half (50%), respectively, after the 2 and 3 treatments. The chance of increasing after the third dose was 3 to 4 times higher in previously infected individuals, regardless of whether the patients were residents or medical professionals. Even though the second booster dose was given more than 6 months after the first, elderly nursing home residents who had a poor response to the first series of the SARS-CoV-2 vaccine were still able to produce acceptable antibody responses.