Is there a difference in the efficacy of COVID-19 vaccine in males and females? - A systematic review and meta-analysis

ABSTRACT

Introduction

Females generally have higher antibody responses to viral vaccines. Our objectives were to compare gender differences in the efficacy of COVID-19 vaccination.

Methods

Data sources: Studies from PubMed, Embase, Cochrane Central Register, Web of Science, ClinicalTrials.gov, and the World Health Organization’s International Clinical Trials Registry Platform.

Results

We included four eligible trials; all were categorized as having a low risk of bias. COVID-19 vaccine was significantly effective in both males and females. Slightly more SARS-CoV-2 infections were recorded in females than in males, but the difference was not significant (RR 1.064 [0.888–1.274]; p = .502, I2 = 5.7%; p = .367, 643,127 participants).

Conclusion

Despite significant biological and behavioral differences between males and females, we found no significant gender differences in the efficacy of the COVID-19 vaccines, especially in younger populations. Further pragmatic trials are needed to confirm the gender differences in protective response of different types of vaccines to different age groups.

KEYWORDS:

• COVID-19 vaccine
• efficacy
• sex

Highlights

1. COVID-19 vaccines were significantly effective in both males and females.

2. Statistical analysis of the vaccinated population showed that slightly more SARS-CoV-2 infections were recorded in females than in males, which was in line with the latest research data in the real-world.

3. There was no significantly correlation between sex-differences and the COVID-19 vaccine efficacy.

Author contributions

Gang Chen had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Zheng Zhu and Lizhen Xu reviewed the literature, extracted the data and completed the analysis. Zheng Zhu provided edits of the manuscript.

Disclosure statement

We declare no competing interests.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website at https://doi.org/10.1080/21645515.2021.1984135.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.