Effectiveness of the CoronaVac Vaccine on Symptomatic COVID-19 Infection, Severe Disease, ICU/semi-ICU Admission, and Mortality in Samut Sakhon Province: a Test-Negative Case-Control Study
DOI:
https://doi.org/10.59096/osir.v15i2.262418Keywords:
COVID-19, CoronaVac, vaccine effectiveness, test-negative study, ThailandAbstract
A mass vaccination campaign with the inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine, CoronaVac, was implemented in Thailand during the early months of the COVID-19 pandemic. As the Delta variant became the dominant strain in the country, we aimed to evaluate the real-world effectiveness of this particular vaccine among adults in Samut Sakhon Province, Thailand. A test-negative case-control study was conducted from 1 Jun to 31 Jul 2021 to evaluate the effectiveness of CoronaVac against symptomatic COVID-19 infection, severe disease, admission to intensive care unit (ICU)/semi-ICU and mortality. We estimated odds ratios using multiple logistic regression. Among 11,371 participants included in the study, 3,116 (27.4%) tested positive for COVID-19 and 3,333 (29.3%) completed two doses of vaccine. The adjusted vaccine effectiveness of two-dose CoronaVac was 65.8% (95% confidence interval (CI) 61.9 – 69.3) for the prevention of symptomatic infection, 71.8% (95% CI 58.5 – 81.6) for severe disease, 72.7% (95% CI 56.6 – 83.9) for ICU/semi-ICU admission and 86.7% (95% CI 34.8 – 99.3) for mortality. Results of this study demonstrate that CoronaVac had moderate effectiveness against symptomatic COVID-19 infection, while it was effective in preventing severe disease, ICU/semi-ICU admission and COVID-19 related deaths in a setting where the two variants were circulating.
References
Emergency Operations Center, Department of Disease Control. The Coronavirus Disease 2019 Situation: Thailand situation update on 23 August 2021. Nonthaburi: Department of Disease Control, Ministry of Public Health, Thailand; 2021 Aug 23 [cited 2021 Aug 31]. 3 p. <https://ddc.moph.go.th/viralpneumonia/eng/file/situation/situation-no592-230864.pdf>
Tanriover MD, Doganay HL, Akova M, Guner HR, Azap A, Akhan S, et al. Efficacy and safety of an inactivated whole-virion SARS-CoV-2 vaccine (CoronaVac): interim results of a double-blind, randomised, placebo-controlled, phase 3 trial in Turkey. Lancet. 2021 Jul 17:398(10296);213–22.
Jara A, Undurraga EA, Gonzalez C, Paredes F, Fontecilla T, Jara G, et al. Effectiveness of an Inactivated SARS-CoV-2 Vaccine in Chile. N Engl J Med. 2021 Sep 2;385(10):875–84.
Ranzani OT, Hitchings MDT, Dorion M, D’Agostini TL, de Paula RC, de Paula OFP, et al. Effectiveness of the CoronaVac vaccine in older adults during a gamma variant associated epidemic of COVID-19 in Brazil: test negative case-control study. BMJ. 2021 Aug 20;374:n2015. doi: 10.1136/bmj.n2015.
Hitchings MDT, Ranzani OT, Torres MSS, de Oliveira SB, Almiron M, Said R, et al. Effectiveness of CoronaVac among healthcare workers in the setting of high SARS-CoV-2 Gamma variant transmission in Manaus, Brazil: A test-negative case-control study. Lancet Reg Health Am. 2021 Sep;1:100025. doi:10.1016/j.lana.2021.100025.
Phucharoen C, Sungkaew N, Sukontapol C, Laongpetch S, Kukiatkul K, Sawangpan K. Interim Estimates of Vaccine Effectiveness of CoronaVac among High Risk Contacts: An empirical study from Phuket. Phuket: Prince of Songkla University; 2021. 1–9 p.
Regional Medical Sciences Center 5 Samut Songkharm. Health Region 5 SARS-CoV-2 Genomic Surveillance: A Preliminary Report. Samut Songkharm (TH): Regional Medical Sciences Center 5 Samut Songkharm, Department of Medical Sciences, Ministry of Public Health; 2021.
Chua H, Feng S, Lewnard JA, Sullivan SG, Blyth CC, Lipsitch M, et al. The Use of Test-negative Controls to Monitor Vaccine Effectiveness: A Systematic Review of Methodology. Epidemiology. 2020 Jan;31(1):43–64.
Lewnard JA, Patel MM, Jewell NP, Verani JR, Kobayashi M, Tenforde MW, et al. Theoretical Framework for Retrospective Studies of the Effectiveness of SARS-CoV-2 Vaccines. Epidemiology. 2021 Jul 1;32(4):508–17.
World Health Organization. Evaluation of COVID-19 vaccine effectiveness: Interim guidance [Internet]. Geneva: World Health Organization; 2021 Mar 17 [cited 2021 Aug 30]. 70 p. <https://www.who.int/publications/i/item/WHO-2019-nCoV-vaccine_effectiveness-measurement-2021.1>
Department of Disease Control. Patient Under Investigation (PUI) Definition [Internet]. Nonthaburi: Department of Disease Control, Ministry of Public Health, Thailand: 2020 Jun 16 [updated 2020 Jun 23, cited 2021 Oct 1]. 2 p. <https://ddc.moph.go.th/viralpneumonia/eng/file/guidelines/g_surveillance_230620.pdf>
O’Neill RT. On sample sizes to estimate the protective efficacy of a vaccine. Stat Med. 1988 Dec;7(12):1279–88.
R Core Team. R: A Language and Environment for Statistical Computing [Internet]. Vienna (Austria): R Foundation for Statistical Computing; 2020 [cited 2021 Sep 10]. <https://www.R-project.org/>
Palacios R, Batista AP, Albuquerque CSN, Patino EG, Santos JDP, Conde MTRP, et al. Efficacy and safety of a COVID-19 inactivated vaccine in healthcare professionals in Brazil: the PROFISCOV Study. SSRN [Preprint]. 2021 Apr 14 [cited 2021 Sep 5]: [66 p.]. <https://ssrn.com/abstract=3822780>
Bueno SM, Abarca K, Gonzalez PA, Galvez NMS, Soto JA, Duarte LF, et al. Safety and Immunogenicity of an Inactivated SARS-CoV-2 Vaccine in a Subgroup of Healthy Adults in Chile. Clin Infect Dis. 2021 Sep 19:ciab823.
Zhang Y, Zeng G, Pan H, Li C, Hu Y, Chu K, et al. Safety, tolerability, and immunogenicity of an inactivated SARS-CoV-2 vaccine in healthy adults aged 18-59 years: a randomised, double-blind, placebo-controlled, phase 1/2 clinical trial. Lancet Infect Dis. 2021 Feb;21(2):181–92.
Hunsawong T, Fernandez S, Buathong R, Khadthasrima N, Rungrojchareonkit K, Lohachanakul J, et al. Limited and Short-Lasting Virus Neutralizing Titers Induced by Inactivated SARS-CoV-2 Vaccine. Emerg Infect Dis. 2021 Dec;27(12):3178–80.
Li M, Yang J, Wang L, Wu Q, Wu Z, Zheng W, et al. A booster dose is immunogenic and will be needed for older adults who have completed two doses vaccination with CoronaVac: a randomised, double-blind, placebo-controlled, phase 1/2 clinical trial. medRxiv [Preprint]. 2021 Aug 8 [cited 2021 Aug 31]. <https://doi.org/10.1101/2021.08.03.21261544>
Pan H, Wu Q, Zeng G, Yang J, Jiang D, Deng X, et al. Immunogenicity and safety of a third dose, and immune persistence of CoronaVac vaccine in healthy adults aged 18-59 years: interim results from a double-blind, randomized, placebo-controlled phase 2 clinical trial. medRxiv [Preprint]. 2021 [cited 2021 Oct 10]. <https://doi.org/10.1101/2021.07.23.21261026>
World Health Organization. Interim recommendations for use of the inactivated COVID-19 vaccine, CoronaVac, developed by Sinovac: Interim guidance [Internet]. Geneva: World Health Organizaiton; 2021 May 24 [updated 2021 Oct 21, cited 2021 Dec 1]. <https://apps.who.int/iris/rest/bitstreams/1382254/retrieve>
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