Background: Nursing home (NH) residents suffered the greatest impact of the COVID-19 pandemic. Limited data are available on vaccine-induced immunity and on the protection ensured by a prior infection in this population. Aims: The present study aims to monitor antibody levels and their persistence over a 6-month period in NH residents according to the history of prior SARS-CoV-2 infection. Methods: We measured anti-trimeric Spike IgG antibody levels in a sample of 395 residents from 25 NHs in 6 Italian Regions at study enrolment (prior to the first dose of vaccine, T0) and then after 2 (T1) and 6 months (T2) following the first vaccine dose. All participants received mRNA vaccines (BNT162b2 or mRNA-1273). Analyses were performed using log-transformed values of antibody concentrations and geometric means (GM) were calculated. Results: Superior humoral immunity was induced in NH residents with previous SARS-CoV-2 infection. (T0: GM 186.6 vs. 6.1 BAU/ml, p < 0.001; T1: GM 5264.1 vs. 944.4 BAU/ml, p < 0.001; T2: GM 1473.6 vs. 128.7 BAU/ml, p < 0.001). Residents with prior SARS-CoV-2 infection receiving two vaccine doses presented significantly higher antibody concentration at T1 and T2. A longer interval between previous infection and vaccination was associated with a better antibody response over time. Discussion: In a frail sample of NH residents, prior SARS-CoV-2 infection was associated with a higher humoral response to vaccination. Number of vaccine doses and the interval between infection and vaccination are relevant parameters in determining humoral immunity. Conclusions: These findings provide important information to plan future immunization policies and disease prevention strategies in a highly vulnerable population.

Humoral immunity induced by mRNA COVID-19 vaccines in Nursing Home Residents previously infected with SARS-CoV-2

Trevisan, Caterina;
2022

Abstract

Background: Nursing home (NH) residents suffered the greatest impact of the COVID-19 pandemic. Limited data are available on vaccine-induced immunity and on the protection ensured by a prior infection in this population. Aims: The present study aims to monitor antibody levels and their persistence over a 6-month period in NH residents according to the history of prior SARS-CoV-2 infection. Methods: We measured anti-trimeric Spike IgG antibody levels in a sample of 395 residents from 25 NHs in 6 Italian Regions at study enrolment (prior to the first dose of vaccine, T0) and then after 2 (T1) and 6 months (T2) following the first vaccine dose. All participants received mRNA vaccines (BNT162b2 or mRNA-1273). Analyses were performed using log-transformed values of antibody concentrations and geometric means (GM) were calculated. Results: Superior humoral immunity was induced in NH residents with previous SARS-CoV-2 infection. (T0: GM 186.6 vs. 6.1 BAU/ml, p < 0.001; T1: GM 5264.1 vs. 944.4 BAU/ml, p < 0.001; T2: GM 1473.6 vs. 128.7 BAU/ml, p < 0.001). Residents with prior SARS-CoV-2 infection receiving two vaccine doses presented significantly higher antibody concentration at T1 and T2. A longer interval between previous infection and vaccination was associated with a better antibody response over time. Discussion: In a frail sample of NH residents, prior SARS-CoV-2 infection was associated with a higher humoral response to vaccination. Number of vaccine doses and the interval between infection and vaccination are relevant parameters in determining humoral immunity. Conclusions: These findings provide important information to plan future immunization policies and disease prevention strategies in a highly vulnerable population.
2022
Fedele, Giorgio; Palmieri, Annapina; Damiano, Cecilia; Di Lonardo, Anna; Leone, Pasqualina; Schiavoni, Ilaria; Trevisan, Caterina; Abbatecola, Angela Marie; Cafariello, Carmine; Malara, Alba; Minchella, Pasquale; Panduri, Giuseppina; Antonelli Incalzi, Raffaele; Palamara, Anna Teresa; Stefanelli, Paola; Onder, Graziano
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/2502937
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