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Kassanjee R, Davies MA, Heekes A, Mahomed H, Hawkridge AJ, Morden E, Jacobs T, Cohen C, Moultrie H, Lessells RJ, Van Der Walt N, Arendse JO, Wolter N, Walaza S, Jassat W, von Gottberg A, Hannan PL, Feikin DR, Cloete K, Boulle A. COVID-19 Vaccine Uptake and Effectiveness by Time since Vaccination in the Western Cape Province, South Africa: An Observational Cohort Study during 2020-2022. Vaccines (Basel) 2024; 12:628. [PMID: 38932357 PMCID: PMC11209070 DOI: 10.3390/vaccines12060628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 05/10/2024] [Accepted: 06/02/2024] [Indexed: 06/28/2024] Open
Abstract
There are few data on the real-world effectiveness of COVID-19 vaccines and boosting in Africa, which experienced widespread SARS-CoV-2 infection before vaccine availability. We assessed the association between vaccination and severe COVID-19 in the Western Cape, South Africa, in an observational cohort study of >2 million adults during 2020-2022. We described SARS-CoV-2 testing, COVID-19 outcomes, and vaccine uptake over time. We used multivariable cox models to estimate the association of BNT162b2 and Ad26.COV2.S vaccination with COVID-19-related hospitalization and death, adjusting for demographic characteristics, underlying health conditions, socioeconomic status proxies, and healthcare utilization. We found that by the end of 2022, 41% of surviving adults had completed vaccination and 8% had received a booster dose. Recent vaccination was associated with notable reductions in severe COVID-19 during periods dominated by Delta, and Omicron BA.1/2 and BA.4/5 (sub)lineages. During the latest Omicron BA.4/5 wave, within 3 months of vaccination or boosting, BNT162b2 and Ad26.COV2.S were each 84% effective against death (95% CIs: 57-94 and 49-95, respectively). However, distinct reductions of effectiveness occurred at longer times post completing or boosting vaccination. Results highlight the importance of continued emphasis on COVID-19 vaccination and boosting for those at high risk of severe COVID-19, even in settings with widespread infection-induced immunity.
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Affiliation(s)
- Reshma Kassanjee
- Centre for Infectious Disease Epidemiology and Research, School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (M.-A.D.); (A.H.); (A.B.)
| | - Mary-Ann Davies
- Centre for Infectious Disease Epidemiology and Research, School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (M.-A.D.); (A.H.); (A.B.)
- Division of Public Health Medicine, School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Centre for Infectious Diseases Research in Africa, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Health Intelligence, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa; (E.M.); (T.J.)
| | - Alexa Heekes
- Centre for Infectious Disease Epidemiology and Research, School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (M.-A.D.); (A.H.); (A.B.)
- Health Intelligence, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa; (E.M.); (T.J.)
| | - Hassan Mahomed
- Division of Health Systems and Public Health, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa; (H.M.); (J.O.A.)
- Metro Health Services, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa
| | - Anthony J. Hawkridge
- Rural Health Services, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa;
| | - Erna Morden
- Health Intelligence, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa; (E.M.); (T.J.)
- School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Theuns Jacobs
- Health Intelligence, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa; (E.M.); (T.J.)
| | - Cheryl Cohen
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa; (C.C.); (N.W.); (S.W.); (A.v.G.)
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Harry Moultrie
- Centre for Tuberculosis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa;
| | - Richard J. Lessells
- KwaZulu-Natal Research Innovation & Sequencing Platform, University of KwaZulu-Natal, Durban 4001, South Africa;
| | - Nicolette Van Der Walt
- Emergency & Clinical Services Support, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa;
| | - Juanita O. Arendse
- Division of Health Systems and Public Health, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa; (H.M.); (J.O.A.)
- Emergency & Clinical Services Support, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa;
| | - Nicole Wolter
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa; (C.C.); (N.W.); (S.W.); (A.v.G.)
- School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Sibongile Walaza
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa; (C.C.); (N.W.); (S.W.); (A.v.G.)
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Waasila Jassat
- Health Practice, Genesis Analytics, Johannesburg 2196, South Africa;
- Division of Public Health Surveillance and Response, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa; (C.C.); (N.W.); (S.W.); (A.v.G.)
- School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Patrick L. Hannan
- Division of Epidemiology and Biostatistics, School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa;
| | - Daniel R. Feikin
- Department of Immunizations, Vaccines, and Biologicals, World Health Organization, CH-1211 Geneva, Switzerland;
| | - Keith Cloete
- Western Cape Department of Health and Wellness, Cape Town 8000, South Africa;
| | - Andrew Boulle
- Centre for Infectious Disease Epidemiology and Research, School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (M.-A.D.); (A.H.); (A.B.)
- Division of Public Health Medicine, School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Centre for Infectious Diseases Research in Africa, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- Health Intelligence, Western Cape Department of Health and Wellness, Cape Town 8000, South Africa; (E.M.); (T.J.)
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Kassanjee R, Davies MA, Heekes A, Mahomed H, Hawkridge AJ, Wolmarans M, Morden E, Jacobs T, Cohen C, Moultrie H, Lessells RJ, Van Der Walt N, Arendse JO, Goeiman H, Mudaly V, Wolter N, Walaza S, Jassat W, von Gottberg A, Hannan PL, Rousseau P, Feikin D, Cloete K, Boulle A. COVID-19 vaccine uptake and effectiveness by time since vaccination in the Western Cape province, South Africa: An observational cohort study during 2020-2022. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.24.24301721. [PMID: 38343866 PMCID: PMC10854330 DOI: 10.1101/2024.01.24.24301721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/18/2024]
Abstract
Background There are few data on the real-world effectiveness of COVID-19 vaccines and boosting in Africa, which experienced high levels of SARS-CoV-2 infection in a mostly vaccine-naïve population, and has limited vaccine coverage and competing health service priorities. We assessed the association between vaccination and severe COVID-19 in the Western Cape, South Africa. Methods We performed an observational cohort study of >2 million adults during 2020-2022. We described SARS-CoV-2 testing, COVID-19 outcomes, and vaccine uptake over time. We used multivariable cox models to estimate the association of BNT162b2 and Ad26.COV2.S vaccination with COVID-19-related hospitalisation and death, adjusting for demographic characteristics, underlying health conditions, socioeconomic status proxies and healthcare utilisation. Results By end 2022, only 41% of surviving adults had completed vaccination and 8% a booster dose, despite several waves of severe COVID-19. Recent vaccination was associated with notable reductions in severe COVID-19 during distinct analysis periods dominated by Delta, Omicron BA.1/2 and BA.4/5 (sub)lineages: within 6 months of completing vaccination or boosting, vaccine effectiveness was 46-92% for death (range across periods), 45-92% for admission with severe disease or death, and 25-90% for any admission or death. During the Omicron BA.4/5 wave, within 3 months of vaccination or boosting, BNT162b2 and Ad26.COV2.S were each 84% effective against death (95% CIs: 57-94 and 49-95, respectively). However, there were distinct reductions of VE at larger times post completing or boosting vaccination. Conclusions Continued emphasis on regular COVID-19 vaccination including boosting is important for those at high risk of severe COVID-19 even in settings with widespread infection-induced immunity.
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Affiliation(s)
- Reshma Kassanjee
- Centre for Infectious Disease Epidemiology and Research, School of Public Health, University of Cape Town, South Africa
| | - Mary-Ann Davies
- Centre for Infectious Disease Epidemiology and Research, School of Public Health, University of Cape Town, South Africa
- Division of Public Health Medicine, School of Public Health, University of Cape Town, South Africa
- Centre for Infectious Diseases Research in Africa, University of Cape Town, South Africa
- Health Intelligence, Western Cape Government Department of Health and Wellness, South Africa
| | - Alexa Heekes
- Centre for Infectious Disease Epidemiology and Research, School of Public Health, University of Cape Town, South Africa
- Health Intelligence, Western Cape Government Department of Health and Wellness, South Africa
| | - Hassan Mahomed
- Division of Health Systems and Public Health, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
- Metro Health Services, Western Cape Government Department of Health and Wellness, South Africa
| | - Anthony J Hawkridge
- Rural Health Services, Western Cape Government Department of Health and Wellness, South Africa
| | | | - Erna Morden
- Health Intelligence, Western Cape Government Department of Health and Wellness, South Africa
- School of Public Health, University of Cape Town, South Africa
| | - Theuns Jacobs
- Health Intelligence, Western Cape Government Department of Health and Wellness, South Africa
| | - Cheryl Cohen
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, South Africa
- School of Public Health, University of the Witwatersrand, South Africa
| | - Harry Moultrie
- Centre for Tuberculosis, National Institute for Communicable Diseases of the National Health Laboratory Service, South Africa
| | - Richard J Lessells
- KwaZulu-Natal Research Innovation & Sequencing Platform, University of KwaZulu-Natal, South Africa
| | - Nicolette Van Der Walt
- Emergency & Clinical Services Support, Western Cape Government Department of Health and Wellness, South Africa
| | - Juanita O Arendse
- Division of Health Systems and Public Health, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
- Emergency & Clinical Services Support, Western Cape Government Department of Health and Wellness, South Africa
| | - Hilary Goeiman
- Western Cape Government Department of Health and Wellness, South Africa
| | - Vanessa Mudaly
- Division of Public Health Medicine, School of Public Health, University of Cape Town, South Africa
- Western Cape Government Department of Health and Wellness, South Africa
| | - Nicole Wolter
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, South Africa
- School of Pathology, University of the Witwatersrand, South Africa
| | - Sibongile Walaza
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, South Africa
- School of Public Health, University of the Witwatersrand, South Africa
| | - Waasila Jassat
- Health Practice, Genesis Analytics, South Africa
- Division of Public Health Surveillance and Response, National Institute for Communicable Diseases of the National Health Laboratory Service, South Africa
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, South Africa
- School of Pathology, University of the Witwatersrand, South Africa
| | - Patrick L Hannan
- Division of Epidemiology and Biostatistics, School of Public Health, University of Cape Town, South Africa
| | - Petro Rousseau
- South African National Department of Health, South Africa
| | - Daniel Feikin
- Department of Immunizations, Vaccines, and Biologicals, World Health Organization, Switzerland
| | - Keith Cloete
- Western Cape Government Department of Health and Wellness, South Africa
| | - Andrew Boulle
- Centre for Infectious Disease Epidemiology and Research, School of Public Health, University of Cape Town, South Africa
- Division of Public Health Medicine, School of Public Health, University of Cape Town, South Africa
- Centre for Infectious Diseases Research in Africa, University of Cape Town, South Africa
- Health Intelligence, Western Cape Government Department of Health and Wellness, South Africa
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