Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort study
BackgroundIn February 2021 Kazakhstan began offering COVID-19 vaccines to adults. Breakthrough SARS-CoV-2 infections raised concerns about real-world vaccine effectiveness. We aimed to evaluate effectiveness of four vaccines against SARS-CoV-2 infection.MethodsWe conducted a retrospective cohort ana...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-06-01
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| Series: | Frontiers in Public Health |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fpubh.2023.1205159/full |
| _version_ | 1797809819477868544 |
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| author | Dilyara Nabirova Dilyara Nabirova Roberta Horth Roberta Horth Manar Smagul Gaukhar Nukenova Aizhan Yesmagambetova Daniel Singer Alden Henderson Alexey Tsoy |
| author_facet | Dilyara Nabirova Dilyara Nabirova Roberta Horth Roberta Horth Manar Smagul Gaukhar Nukenova Aizhan Yesmagambetova Daniel Singer Alden Henderson Alexey Tsoy |
| author_sort | Dilyara Nabirova |
| collection | DOAJ |
| description | BackgroundIn February 2021 Kazakhstan began offering COVID-19 vaccines to adults. Breakthrough SARS-CoV-2 infections raised concerns about real-world vaccine effectiveness. We aimed to evaluate effectiveness of four vaccines against SARS-CoV-2 infection.MethodsWe conducted a retrospective cohort analysis among adults in Almaty using aggregated vaccination data and individual-level breakthrough COVID-19 cases (≥14 days from 2nd dose) using national surveillance data. We ran time-adjusted Cox-proportional-hazards model with sensitivity analysis accounting for varying entry into vaccinated cohort to assess vaccine effectiveness for each vaccine (measured as 1-adjusted hazard ratios) using the unvaccinated population as reference (N = 565,390). We separately calculated daily cumulative hazards for COVID-19 breakthrough among vaccinated persons by age and vaccination month.ResultsFrom February 22 to September 1, 2021, in Almaty, 747,558 (57%) adults were fully vaccinated (received 2 doses), and 108,324 COVID-19 cases (11,472 breakthrough) were registered. Vaccine effectiveness against infection was 79% [sensitivity estimates (SE): 74%–82%] for QazVac, 77% (SE: 71%–81%) for Sputnik V, 71% (SE: 69%–72%) for Hayat-Vax, and 70% (SE: 65%–72%) for CoronaVac. Among vaccinated persons, the 90-day follow-up cumulative hazard for breakthrough infection was 2.2%. Cumulative hazard was 2.9% among people aged ≥60 years versus 1.9% among persons aged 18–39 years (p < 0.001), and 1.2% for people vaccinated in February–May versus 3.3% in June–August (p < 0.001).ConclusionOur analysis demonstrates high effectiveness of COVID-19 vaccines against infection in Almaty similar to other observational studies. Higher cumulative hazard of breakthrough among people ≥60 years of age and during variant surges warrants targeted booster vaccination campaigns. |
| first_indexed | 2024-03-13T06:58:33Z |
| format | Article |
| id | doaj.art-fcf7fa363d9c4c648aa0b30d3af5c711 |
| institution | Directory Open Access Journal |
| issn | 2296-2565 |
| language | English |
| last_indexed | 2024-03-13T06:58:33Z |
| publishDate | 2023-06-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Public Health |
| spelling | doaj.art-fcf7fa363d9c4c648aa0b30d3af5c7112023-06-07T05:12:38ZengFrontiers Media S.A.Frontiers in Public Health2296-25652023-06-011110.3389/fpubh.2023.12051591205159Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort studyDilyara Nabirova0Dilyara Nabirova1Roberta Horth2Roberta Horth3Manar Smagul4Gaukhar Nukenova5Aizhan Yesmagambetova6Daniel Singer7Alden Henderson8Alexey Tsoy9Division of Global Health Protection in Central Asia, United States Centers for Disease Control and Prevention, Almaty, KazakhstanCentral Asia Field Epidemiology Training Program, Asfendiyarov Kazakh National Medical University, Almaty, KazakhstanDivision of Global Health Protection in Central Asia, United States Centers for Disease Control and Prevention, Almaty, KazakhstanCentral Asia Field Epidemiology Training Program, Asfendiyarov Kazakh National Medical University, Almaty, KazakhstanScientific and Practical Center of Sanitary-Epidemiological Examination and Monitoring, Branch of the National Center for Public Health, Almaty, KazakhstanScientific and Practical Center of Sanitary-Epidemiological Examination and Monitoring, Branch of the National Center for Public Health, Almaty, KazakhstanCommittee of Sanitary and Epidemiological Control, Ministry of Healthcare, Astana, KazakhstanDivision of Global Health Protection in Central Asia, United States Centers for Disease Control and Prevention, Almaty, KazakhstanDivision of Global Health Protection, United States Centers for Disease Control and Prevention, Atlanta, GA, United StatesOffice of the Minister, Ministry of Healthcare, Astana, KazakhstanBackgroundIn February 2021 Kazakhstan began offering COVID-19 vaccines to adults. Breakthrough SARS-CoV-2 infections raised concerns about real-world vaccine effectiveness. We aimed to evaluate effectiveness of four vaccines against SARS-CoV-2 infection.MethodsWe conducted a retrospective cohort analysis among adults in Almaty using aggregated vaccination data and individual-level breakthrough COVID-19 cases (≥14 days from 2nd dose) using national surveillance data. We ran time-adjusted Cox-proportional-hazards model with sensitivity analysis accounting for varying entry into vaccinated cohort to assess vaccine effectiveness for each vaccine (measured as 1-adjusted hazard ratios) using the unvaccinated population as reference (N = 565,390). We separately calculated daily cumulative hazards for COVID-19 breakthrough among vaccinated persons by age and vaccination month.ResultsFrom February 22 to September 1, 2021, in Almaty, 747,558 (57%) adults were fully vaccinated (received 2 doses), and 108,324 COVID-19 cases (11,472 breakthrough) were registered. Vaccine effectiveness against infection was 79% [sensitivity estimates (SE): 74%–82%] for QazVac, 77% (SE: 71%–81%) for Sputnik V, 71% (SE: 69%–72%) for Hayat-Vax, and 70% (SE: 65%–72%) for CoronaVac. Among vaccinated persons, the 90-day follow-up cumulative hazard for breakthrough infection was 2.2%. Cumulative hazard was 2.9% among people aged ≥60 years versus 1.9% among persons aged 18–39 years (p < 0.001), and 1.2% for people vaccinated in February–May versus 3.3% in June–August (p < 0.001).ConclusionOur analysis demonstrates high effectiveness of COVID-19 vaccines against infection in Almaty similar to other observational studies. Higher cumulative hazard of breakthrough among people ≥60 years of age and during variant surges warrants targeted booster vaccination campaigns.https://www.frontiersin.org/articles/10.3389/fpubh.2023.1205159/fullCOVID-19vaccine effectivenessbreakthrough infectionSARS-CoV-2QazVacKazakhstan |
| spellingShingle | Dilyara Nabirova Dilyara Nabirova Roberta Horth Roberta Horth Manar Smagul Gaukhar Nukenova Aizhan Yesmagambetova Daniel Singer Alden Henderson Alexey Tsoy Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort study Frontiers in Public Health COVID-19 vaccine effectiveness breakthrough infection SARS-CoV-2 QazVac Kazakhstan |
| title | Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort study |
| title_full | Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort study |
| title_fullStr | Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort study |
| title_full_unstemmed | Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort study |
| title_short | Effectiveness of four vaccines in preventing SARS-CoV-2 infection in Almaty, Kazakhstan in 2021: retrospective population-based cohort study |
| title_sort | effectiveness of four vaccines in preventing sars cov 2 infection in almaty kazakhstan in 2021 retrospective population based cohort study |
| topic | COVID-19 vaccine effectiveness breakthrough infection SARS-CoV-2 QazVac Kazakhstan |
| url | https://www.frontiersin.org/articles/10.3389/fpubh.2023.1205159/full |
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