Breakthrough infections, hospital admissions, and mortality after major COVID-19 vaccination profiles: A prospective cohort study

Mingkwan Wichaidit; Tanawin Nopsopon; Krittiyaporn Sunan; Phanupong Phutrakool; Puripant Ruchikachorn; Dittaya Wanvarie; Ploy Naruemon Pratanwanich; Nontawit Cheewaruangroj; Proadpran Punyabukkana; Krit Pongpirul

doi:10.1016/j.lansea.2022.100106

Breakthrough infections, hospital admissions, and mortality after major COVID-19 vaccination profiles: A prospective cohort study

Lancet Reg Health Southeast Asia. 2023 Jan:8:100106. doi: 10.1016/j.lansea.2022.100106. Epub 2022 Nov 4.

Authors

Affiliations

¹ Institute of Dermatology, Department of Medical Services, Ministry of Public Health, Bangkok, Thailand.
² School of Global Health and Department of Preventive and Social Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
³ Harvard T.H. Chan School of Public Health, Boston, MA, USA.
⁴ Division of Allergy and Clinical Immunology, Brigham and Women's and Harvard Medical School, Boston, MA, USA.
⁵ Chulalongkorn Business School, Chulalongkorn University, Bangkok, Thailand.
⁶ Department of Mathematics and Computer Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
⁷ Government Big Data Institute (GBDi), Digital Economy Promotion Agency, Ministry of Digital Economy and Society, Bangkok, Thailand.
⁸ Department of Computer Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand.
⁹ Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
¹⁰ Clinical Research Center, Bumrungrad International Hospital, Bangkok, Thailand.

Abstract

Background: Several COVID-19 vaccination rollout strategies are implemented. Real-world data from the large-scale, government-mandated Central Vaccination Center (CVC), Thailand, could be used for comparing the breakthrough infection, across all available COVID-19 vaccination profiles.

Methods: This prospective cohort study combined the vaccine profiles from the CVC registry with three nationally validated outcome datasets to assess the breakthrough COVID-19 infection, hospitalization, and death among Thais individuals who received at least one dose of the COVID-19 vaccine. The outcomes were analyzed by comparing vaccine profiles to investigate the shot effect and homologous effect.

Findings: Of 2,407,315 Thais who had at least one dose of COVID-19 vaccine, 63,469 (2.75%) had breakthrough infection, 42,001 (1.79%) had been hospitalized, and 431 (0.02%) died. Per one vaccination shot added, there was an 18% risk reduction of breakthrough infection (adjusted hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.80-0.82), a 25% risk reduction of hospitalization (HR 0.75, 95% CI 0.73-0.76), and a 96% risk reduction of mortality (HR 0.04, 95% CI 0.03-0.06). The heterologous two-shot vaccine profiles had a higher protective effect against infection, hospitalization, and mortality compared to the homologous counterparts.

Interpretation: COVID-19 breakthrough infection, hospitalization, and death differ across vaccination profiles that had a different number of shots and types of vaccines.

Funding: This study did not involve any funding.

Keywords: AZ, ChAdOx1 nCoV-19, Vaxzevria, Cambridge, AstraZeneca, UK; CO-Ward, Thai COVID-19 hospitalization dataset; CVC, central vaccination center; Co-Lab, Thai COVID-19 infection dataset; IN, inactivated vaccine; IgG, immunoglobulin G; MN, mRNA-1273, Moderna, NIAID, USA; MR, mRNA vaccine; PDPA, Personal Data Protection Act; PEC, primary eligibiligy criteria; PZ, BNT162b2, Comirnaty, BioNTech, Mainz, Germany; RT-PCR, reverse transcription-polymerase chain reaction; SP, Sinopharm, Beijing Institute of Biological Products, China; SV, CoronaVac, Sinovac Biotech, Beijing, China; VSDMC, Vaccine Safety and Data Monitoring Committee; VV, viral vector vaccine.