Abstract

Background: This study aims to evaluate waning effectiveness against severe and fatal COVID-19 with two to three doses of CoronaVac/BNT162b2, where data are limited. Methods: A case–control study included individuals aged ≥18 years, unvaccinated or received two to three doses of CoronaVac/BNT162b2, using electronic healthcare databases in Hong Kong. Those with first COVID-19-related hospitalization, severe complications, or mortality between 1 January and 15 August 2022 were defined as cases and matched with up-to-10 controls by age, sex, index date, and Charlson Comorbidity Index. Vaccine effectiveness (VE) against COVID-19-related outcomes was estimated at different time intervals from second and third-dose vaccination (0–13 up-to 210–240 days) using conditional logistic regression adjusted for comorbidities and medications. Results: By 211–240 days after second dose, VE against COVID-19-related hospitalization reduced to 46.6% (40.7–51.8%) for BNT162b2 and 36.2% (28.0–43.4%) for CoronaVac, and VE against COVID-19-related mortality were 73.8% (55.9–84.4%) and 76.6% (60.8–86.0%). After third dose, VE against COVID-19-related hospitalization decreased from 91.2% (89.5–92.6%) for BNT162b2 and 76.7% (73.7–79.4%) for CoronaVac at 0–13 days, to 67.1% (60.4–72.6%) and 51.3% (44.2–57.5%) at 91–120 days. VE against COVID-19-related mortality for BNT162b2 remained high from 0–13 days [98.2% (95.0–99.3%)] to 91–120 days [94.6% (77.7–98.7%)], and for CoronaVac reduced from 0–13 days [96.7% (93.2–98.4%)] to 91–120 days [86.4% (73.3–93.1%)]. Conclusions: Significant risk reduction against COVID-19-related hospitalization and mortality after CoronaVac or BNT162b2 vaccination was observed for >240 and >120 days after second and third doses compared to unvaccinated, despite significant waning over time. Timely administration of booster doses could provide higher levels of protection.

Details

Title
Waning effectiveness against COVID-19-related hospitalization, severe complications, and mortality with two to three doses of CoronaVac and BNT162b2: a case–control study
Author
Vincent Ka Chun Yan 1 ; Eric Yuk Fai Wan 2 ; Ye, Xuxiao 1 ; Anna Hoi Ying Mok 3 ; Francisco Tsz Tsun Lai 4   VIAFID ORCID Logo  ; Celine Sze Ling Chui 5 ; Li, Xue 6 ; King Ho Wong, Carlos 2 ; Li, Philip Hei 7 ; Ma, Tiantian 4 ; Qin, Simon 4 ; Lau, Chak Sing 7 ; Wong, Ian Chi Kei 8 ; Yin Chan, Esther Wai 9 

1  Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong, People’s Republic of China 
2  Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong, People’s Republic of China; Laboratory of Data Discovery for Health (D 2 4H), Hong Kong Science and Technology Park, Hong Kong, People’s Republic of China; Department of Family Medicine and Primary Care, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People’s Republic of China 
3  Department of Family Medicine and Primary Care, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People’s Republic of China 
4  Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong, People’s Republic of China; Laboratory of Data Discovery for Health (D 2 4H), Hong Kong Science and Technology Park, Hong Kong, People’s Republic of China 
5  Laboratory of Data Discovery for Health (D 2 4H), Hong Kong Science and Technology Park, Hong Kong, People’s Republic of China; School of Nursing, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People’s Republic of China; School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People’s Republic of China 
6  Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong, People’s Republic of China; Laboratory of Data Discovery for Health (D 2 4H), Hong Kong Science and Technology Park, Hong Kong, People’s Republic of China; Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People’s Republic of China 
7  Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People’s Republic of China 
8  Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong, People’s Republic of China; Laboratory of Data Discovery for Health (D 2 4H), Hong Kong Science and Technology Park, Hong Kong, People’s Republic of China; Research Department of Practice and Policy, School of Pharmacy, University College London, London, UK; Aston Pharmacy School, Aston University, Birmingham, UK; Department of Pharmacy, The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China 
9  Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong, People’s Republic of China; Laboratory of Data Discovery for Health (D 2 4H), Hong Kong Science and Technology Park, Hong Kong, People’s Republic of China; Department of Pharmacy, The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China; The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, People’s Republic of China 
Publication year
2023
Publication date
Dec 2023
Publisher
Taylor & Francis Ltd.
e-ISSN
22221751
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1080/22221751.2023.2209201
ProQuest document ID
2867486711
Copyright
© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group, on behalf of Shanghai Shangyixun Cultural Communication Co., Ltd. This work is licensed under the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.