Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021–2022
BACKGROUND: Given their high-risk resident population, nursing homes were critical institutions in the COVID-19 pandemic, calling for continued monitoring and vaccine administration to healthcare workers and residents. Here, we studied long-term severe acute respiratory syndrome coronavirus 2 (SARS...
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| Format: | Article |
| Language: | English |
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SMW supporting association (Trägerverein Swiss Medical Weekly SMW)
2023-12-01
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| Series: | Swiss Medical Weekly |
| Online Access: | https://smw.ch/index.php/smw/article/view/3502 |
| _version_ | 1797378100398391296 |
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| author | Lisa Perrig Irene A. Abela Nicolas Banholzer Annette Audigé Selina Epp Catrina Mugglin Kathrin Zürcher Matthias Egger Alexandra Trkola Lukas Fenner |
| author_facet | Lisa Perrig Irene A. Abela Nicolas Banholzer Annette Audigé Selina Epp Catrina Mugglin Kathrin Zürcher Matthias Egger Alexandra Trkola Lukas Fenner |
| author_sort | Lisa Perrig |
| collection | DOAJ |
| description |
BACKGROUND: Given their high-risk resident population, nursing homes were critical institutions in the COVID-19 pandemic, calling for continued monitoring and vaccine administration to healthcare workers and residents. Here, we studied long-term severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity in vaccinated and unvaccinated healthcare workers and residents of a nursing home in Switzerland between February 2021 and June 2022.
METHODS: Our study comprised 45 participants, of which 39 were healthcare workers and six were residents. All participants were offered a maximum of three mRNA vaccine doses (Pfizer/BioNTech, BNT162b2) in December 2020, January 2021, and November/December 2021. Thirty-five participants received three vaccinations, seven either one or two, and three remained unvaccinated. We collected four blood samples: one in March 2021 and three during follow-ups in November 2021, February 2022, and June 2022. We performed a multifactorial serological SARS-CoV-2 assay (ABCORA) for immunoglobulin G, A, and M responses to spike (receptor-binding domain, S1, and S2) and nucleocapsid (N) proteins. Furthermore, we assessed predicted neutralisation activity based on signal over cutoff in ABCORA. We collected epidemiological data from participants via a standardised questionnaire.
RESULTS: Thirty-two (71%) of the 45 participants showed hybrid immunity from combined vaccination and previous infection; 10 (22%) had only vaccine-induced immunity; and three (7%) had only post-infection immunity. Participants with hybrid immunity showed the highest predicted neutralisation activity at the end of the study period (median Sum S1 = 273), and unvaccinated participants showed the lowest (median Sum S1 = 41). Amongst participants who reported a SARS-CoV-2 infection, median Sum S1 levels increased with the number of vaccinations (p = 0.077). The healthcare worker group showed a significant time-dependent decrease in median Sum S1 after base immunisation (93% decrease, p = 0.0005) and the booster dose (26% decrease, p = 0.010). Predicted neutralisation activity was lower amongst residents (adjusted ratio of means [AM] = 0.7, 95% confidence interval [CI] = 0.3–1.0) and amongst smokers (AM = 0.5, 95% CI 0.3–0.8). Activity increased with the number of vaccinations (booster: AM = 3.6, 95% CI 1.5–8.8; no booster: AM = 2.3, 95% CI 0.9–2.5). Positive SARS-CoV-2 infection status tended to confer higher predicted neutralisation levels (AM = 1.5, 95% CI 0.9–2.5).
CONCLUSIONS: Our study of the long-term serological course of SARS-CoV-2 in a nursing home showed that the first SARS-CoV-2 booster vaccine was essential for maintaining antiviral antibody levels. Hybrid immunity sustained SARS-CoV-2 immunity at the highest level. In critical settings such as nursing homes, monitoring the SARS-CoV-2 immune status may guide booster vaccinations.
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| first_indexed | 2024-03-08T20:02:56Z |
| format | Article |
| id | doaj.art-43c4abed8bfa45fdaaad1391800d5574 |
| institution | Directory Open Access Journal |
| issn | 1424-3997 |
| language | English |
| last_indexed | 2024-03-08T20:02:56Z |
| publishDate | 2023-12-01 |
| publisher | SMW supporting association (Trägerverein Swiss Medical Weekly SMW) |
| record_format | Article |
| series | Swiss Medical Weekly |
| spelling | doaj.art-43c4abed8bfa45fdaaad1391800d55742023-12-23T12:52:46ZengSMW supporting association (Trägerverein Swiss Medical Weekly SMW)Swiss Medical Weekly1424-39972023-12-011531210.57187/s.3502Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021–2022Lisa PerrigIrene A. AbelaNicolas BanholzerAnnette AudigéSelina EppCatrina MugglinKathrin ZürcherMatthias EggerAlexandra TrkolaLukas Fenner BACKGROUND: Given their high-risk resident population, nursing homes were critical institutions in the COVID-19 pandemic, calling for continued monitoring and vaccine administration to healthcare workers and residents. Here, we studied long-term severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity in vaccinated and unvaccinated healthcare workers and residents of a nursing home in Switzerland between February 2021 and June 2022. METHODS: Our study comprised 45 participants, of which 39 were healthcare workers and six were residents. All participants were offered a maximum of three mRNA vaccine doses (Pfizer/BioNTech, BNT162b2) in December 2020, January 2021, and November/December 2021. Thirty-five participants received three vaccinations, seven either one or two, and three remained unvaccinated. We collected four blood samples: one in March 2021 and three during follow-ups in November 2021, February 2022, and June 2022. We performed a multifactorial serological SARS-CoV-2 assay (ABCORA) for immunoglobulin G, A, and M responses to spike (receptor-binding domain, S1, and S2) and nucleocapsid (N) proteins. Furthermore, we assessed predicted neutralisation activity based on signal over cutoff in ABCORA. We collected epidemiological data from participants via a standardised questionnaire. RESULTS: Thirty-two (71%) of the 45 participants showed hybrid immunity from combined vaccination and previous infection; 10 (22%) had only vaccine-induced immunity; and three (7%) had only post-infection immunity. Participants with hybrid immunity showed the highest predicted neutralisation activity at the end of the study period (median Sum S1 = 273), and unvaccinated participants showed the lowest (median Sum S1 = 41). Amongst participants who reported a SARS-CoV-2 infection, median Sum S1 levels increased with the number of vaccinations (p = 0.077). The healthcare worker group showed a significant time-dependent decrease in median Sum S1 after base immunisation (93% decrease, p = 0.0005) and the booster dose (26% decrease, p = 0.010). Predicted neutralisation activity was lower amongst residents (adjusted ratio of means [AM] = 0.7, 95% confidence interval [CI] = 0.3–1.0) and amongst smokers (AM = 0.5, 95% CI 0.3–0.8). Activity increased with the number of vaccinations (booster: AM = 3.6, 95% CI 1.5–8.8; no booster: AM = 2.3, 95% CI 0.9–2.5). Positive SARS-CoV-2 infection status tended to confer higher predicted neutralisation levels (AM = 1.5, 95% CI 0.9–2.5). CONCLUSIONS: Our study of the long-term serological course of SARS-CoV-2 in a nursing home showed that the first SARS-CoV-2 booster vaccine was essential for maintaining antiviral antibody levels. Hybrid immunity sustained SARS-CoV-2 immunity at the highest level. In critical settings such as nursing homes, monitoring the SARS-CoV-2 immune status may guide booster vaccinations. https://smw.ch/index.php/smw/article/view/3502 |
| spellingShingle | Lisa Perrig Irene A. Abela Nicolas Banholzer Annette Audigé Selina Epp Catrina Mugglin Kathrin Zürcher Matthias Egger Alexandra Trkola Lukas Fenner Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021–2022 Swiss Medical Weekly |
| title | Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021–2022 |
| title_full | Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021–2022 |
| title_fullStr | Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021–2022 |
| title_full_unstemmed | Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021–2022 |
| title_short | Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021–2022 |
| title_sort | long term course of neutralising antibodies against sars cov 2 in vaccinated and unvaccinated staff and residents in a swiss nursing home a cohort study 2021 2022 |
| url | https://smw.ch/index.php/smw/article/view/3502 |
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