The efficacy and effectiveness of the COVID-19 vaccines in reducing infection, severity, hospitalization, and mortality: a systematic review

ABSTRACT

With the relatively rapid development of the COVID-19 pandemic, vaccine development has become crucial for limiting disease transmission. The accelerated growth in the approved COVID-19 vaccines has sparked concerns about their efficacies which have been assessed by many studies. This systematic review compares the efficacy and effectiveness of seven COVID-19 vaccines. A comprehensive systematic literature search was performed using several databases to identify studies reporting the effectiveness or the efficacy of the vaccines. Only 42 studies met our inclusion criteria, which revealed that the COVID-19 vaccines have successfully reduced the rates of infections, severity, hospitalization, and mortality among the different populations. The full-dose regimen of the Pfizer/BioNTech vaccine is the most effective against infections with the B.1.1.7 and B.1.351 variants. Despite of the high effectiveness of some of the COVID-19 vaccines, more efforts are required to test their effectiveness against the other newly emerging variants.

KEYWORDS:

• COVID-19
• vaccine
• effectiveness
• efficacy

Acknowledgments

We would like to thank Mr. Sa’ad Laws for his help during the early phases of this project including developing the search strategy and importing papers. We would like also to thank Weill Cornell Medicine-Qatar for the continuous support and to specifically thank Weill Cornell Medicine - Qatar Distributed eLibrary for funding the publication of this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data sharing

The data that supports the findings of this study are available in the supplementary material of this article.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website at https://doi.org/10.1080/21645515.2022.2027160.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.