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

Abstract

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.

Graphical abstract

Figure 1

The severity of vaccine-related ADRs in clinical trials Stacked bar chart showing the percentage of four ADRs grade after dose 1 or dose 2 of COVID-19 vaccines. (A) pain, (B) swelling, (C) fever, (D) fatigue, (E) chills, (F) muscle pain (myalgia), (G) joint pain (arthralgia), and (H) headache. Grade 1 (dark blue), grade 2 (light blue), grade 3 (red), and grade 4 (brown).

Figure 2

Forest plot of the incidence of thromboembolic events and myocarditis/pericarditis events Meta-analysis was performed using R statistical software. Event rates and their corresponding 95% confidence intervals were estimated using both a fixed-effects model and a random-effects model. (A) Thromboembolic events and (B) myocarditis/pericarditis events.

Figure 3

The incidence of ADRs of RNA-based vaccine from real-world data (VAERS) Log-rank test of ADRs onset time stratified by (A) vaccine type, (B) age, and (C) gender. (D) Heatmap showing the incidence of ADRs. (∗ADRs Spectrum: due to the limitation of figure size, the details are shown in Table S5.)

Figure 4

The subgroup analyses of ADRs in RNA-based vaccine from real-world data (VAERS) To evaluate the tolerance of the vaccine in different populations, we conducted subgroup analyses stratified by age, sex, and vaccine manufacturer. All ADRs with incidences higher than 5% were included. (∗No application: the incidences of ADRs under 5% in the subgroups were defined as “no application,” which were not tested by χ².)