A comprehensive analysis of the efficacy and safety of COVID-19 vaccines

Mol Ther. 2021 Sep 1;29(9):2794-2805. doi: 10.1016/j.ymthe.2021.08.001. Epub 2021 Aug 6.


The numbers of cases and deaths from coronavirus disease 2019 (COVID-19) are continuously increasing. Many people are concerned about the efficacy and safety of the COVID-19 vaccines. We performed a comprehensive analysis of the published trials of COVID-19 vaccines and the real-world data from the Vaccine Adverse Event Reporting System. Globally, our research found that the efficacy of all vaccines exceeded 70%, and RNA-based vaccines had the highest efficacy of 94.29%; moreover, Black or African American people, young people, and males may experience greater vaccine efficacy. The spectrum of vaccine-related adverse drug reactions (ADRs) is extremely broad, and the most frequent ADRs are pain, fatigue, and headache. Most ADRs are tolerable and are mainly grade 1 or 2 in severity. Some severe ADRs have been identified (thromboembolic events, 21-75 cases per million doses; myocarditis/pericarditis, 2-3 cases per million doses). In summary, vaccines are a powerful tool that can be used to control the COVID-19 pandemic, with high efficacy and tolerable ADRs. In addition, the spectrum of ADRs associated with the vaccines is broad, and most of the reactions appear within a week, although some may be delayed. Therefore, ADRs after vaccination need to be identified and addressed in a timely manner.

Keywords: COVID-19; SARS-CoV-2; efficacy; safety; vaccine.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Black People
  • COVID-19 / epidemiology*
  • COVID-19 / ethnology
  • COVID-19 / prevention & control*
  • COVID-19 / virology
  • COVID-19 Vaccines / adverse effects*
  • Clinical Trials, Phase III as Topic
  • Female
  • Humans
  • Immunogenicity, Vaccine
  • Incidence
  • Male
  • Middle Aged
  • Pandemics / prevention & control*
  • Retrospective Studies
  • SARS-CoV-2 / immunology*
  • Treatment Outcome
  • Vaccination / methods*
  • Vaccines, Synthetic / adverse effects*
  • White People
  • Young Adult


  • COVID-19 Vaccines
  • Vaccines, Synthetic
  • mRNA Vaccine