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. 2023 Dec 14:11:1269194.
doi: 10.3389/fpubh.2023.1269194. eCollection 2023.

Inactivated vaccine effectiveness against symptomatic COVID-19 in Fujian, China during the Omicron BA.2 outbreak

Wenjing Ye #  1 , Kangguo Li #  2 , Zeyu Zhao #  2 , Shenggen Wu #  1 , Huimin Qu  2 , Yichao Guo  2 , Buasiyamu Abudunaibi  2 , Wu Chen  1 , Shaojian Cai  1 , Cailin Chen  1 , Jiawei Lin  1 , Zhonghang Xie  1 , Meirong Zhan  1 , Jianming Ou  1 , Yanqin Deng  1 , Tianmu Chen  2 , Kuicheng Zheng  1
Affiliations

Inactivated vaccine effectiveness against symptomatic COVID-19 in Fujian, China during the Omicron BA.2 outbreak

Wenjing Ye et al. Front Public Health. .

Abstract

Objective: More than 90% of the Chinese population have completed 2 doses of inactivated COVID-19 vaccines in Mainland China. However, after China government abandoned strict control measures, many breakthrough infections appeared, and vaccine effectiveness against Omicron BA.2 infection was uncertain. This study aims to investigate the real-world effectiveness of widely used inactivated vaccines during the wave of Omicron variants.

Methods: Test-negative case-control study was conducted in this study to analyze the vaccine effectiveness against symptomatic disease caused by the Omicron variant (BA.2) in Fujian, China. Conditional logistic regression was selected to estimate the vaccine effectiveness.

Results: The study found the vaccine effectiveness against symptomatic COVID-19 is 32.46% (95% CI, 8.08% to 50.37%) at 2 to 8 weeks, and 27.05% (95% CI, 1.23% to 46.12%) at 12 to 24 weeks after receiving booster doses of the inactivated vaccine. Notably, the 3-17 years group had higher vaccine effectiveness after 2 doses than the 18-64 years and over 65 years groups who received booster doses.

Conclusion: Inactivated vaccines alone may not offer sufficient protection for all age groups before the summer of 2022. To enhance protection, other types of vaccines or bivalent vaccines should be considered.

Keywords: COVID-19; Omicron BA.2; SARS-CoV-2; inactivated vaccine; vaccine effectiveness (VE).

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Participants selection progress for investing inactivated vaccine effectiveness.
Figure 2
Figure 2
The estimated effectiveness of inactivated COVID-19 vaccines against symptomatic SARS-CoV-2 infections caused by Omicron BA.2. Unadjusted (A) and adjusted (B) logistic conditional model by age group (3–17 years, 18–64 years and older than 65 years) and gender (male and female) to estimated vaccine effectiveness by various intervals.
Figure 3
Figure 3
Adjusted vaccine effectiveness of inactivated COVID-19 vaccines by various vaccine doses against symptomatic SARS-CoV-2 infections caused by Omicron BA.2. (A) 1 dose inactivated vaccine effectiveness. (B) 2 doses inactivated vaccine effectiveness. (C) Booster dose inactivated vaccine effectiveness. *Model adjusted by gender (male and female); **Model adjusted by age groups (3–17 years, 18–64 years, and more than 65 years); ***Model adjusted by age groups and gender.
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References

    1. Leung K, Lau EH, Wong CK, Leung GM, Wu JT. Estimating the transmission dynamics of SARS-CoV-2 Omicron BF.7 in Beijing after adjustment of the zero-COVID policy in November–December 2022. Nat Med. (2023) 29:579–82. 10.1038/s41591-023-02212-y - DOI - PubMed
    1. Fu Y, Zhao J, Wei X, Han P, Yang L, Ren T, et al. . Effectiveness and cost-effectiveness of inactivated vaccine to address COVID-19 pandemic in China: evidence from randomized control trials and real-world studies. Front Public Health. (2022) 10:917732. 10.3389/fpubh.2022.917732 - DOI - PMC - PubMed
    1. Wan EY, Mok AH, Yan VK, Wang B, Zhang R, Hong SN, et al. . Vaccine effectiveness of BNT162b2 and CoronaVac against SARS-CoV-2 Omicron BA.2 infection, hospitalisation, severe complications, cardiovascular disease and mortality in patients with diabetes mellitus: A case control study. J Infect. (2022) 85:e140–4. 10.1016/j.jinf.2022.08.008 - DOI - PMC - PubMed
    1. Prc N. H. C. Diagnosis and treatment plan for COVID-19 (Trial Version 9). (2022). Available online at: http://www.gov.cn/zhengce/zhengceku/2022-03/15/content_5679257.htm (accessed November 10, 2023).
    1. World Health Organization . Enhancing response to Omicron SARS-CoV-2 variant: Technical brief and priority actions for Member States. Geneva, Switzerland: World Health Organization; (2022). Available online at: https://www.who.int/docs/default-source/coronaviruse/2022-01-21-global-t... (accessed November 10, 2023).

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