•Long-term care residents are particularly vulnerable to COVID-19.•The prompt application of restrictive procedures might prevent the spread and progression of SARS-CoV-2 infection in assisted living facilities in the short term.•SARS-CoV-2 vaccination of residents and staff members would contribute to control/limit the prevalence and the spread of the virus. Here, we aimed to describe the clinical outcomes of the residents of a long-term care facility during its closure to visitors and suppliers in response to the first COVID-19 pandemic from February 23 to June 22, 2020, and the results of the facility-wide SARS-CoV-2 testing of residents and staff in June 2020 before its partially reopening. Seventy-four residents and 53 members of staff were included in the present study. The staff underwent nasopharyngeal swab tests for SARS-CoV-2, and both the staff and residents underwent serological tests to detect IgG antibodies against SARS-CoV-2. The results of all of the tests were negative. Conversely, 94% of residents and 38% members of the staff were tested positive to the nasopharyngeal swab tests during the second COVID-19 pandemic wave (data collected from November 1 to November 30, 2020). Our experience suggests that, in the presence of a life-threatening pandemic such as SARS-CoV-2 infection, the prompt use of restrictive procedures can prevent the spread and progression of disease in assisted living facilities in the short term but may fail in the long term, especially when the prevalence of the COVID-19 greatly increased outside the facility enhancing the risk of import the disease from outside. SARS-CoV-2 vaccination of residents and staff members would contribute to control/limit the prevalence and the spread of the virus.