Safety and Efficacy of COVID-19 Vaccine in Africa: Systematic Review

Abstract

Background

Coronavirus disease 2019 (COVID-19) pandemic scared the whole world at the end of 2019, which is a communicable respiratory disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In South Africa and other African countries, the COVID-19 vaccines were subsequently approved for emergency use by the respective national regulatory authorities. There is a paucity of aggregated data that revealed the safety and efficacy of COVID-19 vaccines in Africa.

Objective

The aim of this systematic review was to synthesize the literature on the safety and efficacy of the COVID-19 vaccine which was given in Africa.

Methods

A systematic search was conducted on Science Direct, PubMed, EMBASE, Google Scholar, CINAHL, Cochrane Library, and direct Google searches. Only studies written in English and published articles from 2019 to October 30, 2022, which comprise nine randomized clinical trials (RCT), and four different studies including a single-arm implementation trials, prospective study, retrospective cohort study, and test-negative designs were included.

Results

A total of 13 studies were included which contain 810,466 participants from Africa. Of these, 62.18% of the participants were female. The efficacy of COVID-19 vaccine in Africa ranges from 41.7% to 100%. Moreover, vaccine efficacy against COVID-19 variants ranges from −5.7% to 100%. In general, systemic and local adverse events following vaccination in most trials were reported with a similar pattern between the placebo and vaccine groups. Out of the total reported adverse events, most of them were mild to moderate, whereas a few were serious.

Conclusion

Almost all current COVID‐19 vaccines appear to be safe for African study participants. Regarding efficacy, the protein subunit vaccine and mRNA vaccine exhibited high efficacy (100%) in this group of participants. However, Ad26. COV2.S and ChAdOx1 nCoV-19 COVID-19 vaccines are not effective against the delta variant and B.1.351 variant, respectively.

Keywords:

• safety
• immunogenicity
• efficacy
• COVID-19 vaccine
• Africa

Abbreviations

ACIP, Advisory Committee on Immunization Practices; AEs, adverse effects; SAEs, serious adverse effects; Alum, aluminum hydroxide; B.1.1.7, Alpha variant; B.1.1.529, Omicron variant; B.1.351, Beta variant; BAU, binding antibody units; Anti-spike (S) IgG, severe acute respiratory syndrome coronavirus-2 antibody (immunoglobulin G); BLA, Biologics License Application; CpG, cytosine phosphoguanine; ELISA, enzyme-linked immunosorbent assay; EU, ELISA Units; EUA, Emergency Use Authorization; FDA, Food and Drug Administration; GMTs, geometric mean titers; HCWs, healthcare workers; HIV, human immunodeficiency virus; ICU, intensive care unit; IGHV1-69 gene, Immunoglobulin heavy variable 1-69 gene; LNP, lipid nanoparticles; MHC, major histocompatibility complex; NIAID, National Institute of Allergy and Infectious Disease; NIPs, National Immunization Programs; P.1, Gamma variant; PCR, polymerase chain reaction; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; RBD, receptor-binding domain; RCT, randomized clinical trial; RT-PCR, reverse transcription polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome-coronavirus-2; SCRs, seroconversion rates; VE, vaccine efficacy; WHO, World Health Organization.

Data Sharing Statement

All data generated during the study were included in this systematic review.

Acknowledgment

The authors would like to acknowledge all cited authors for their contribution in the field of this research area and Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Science, Addis Ababa University, Addis Ababa, Ethiopia.

Disclosure

The authors declare that they have no competing interests.

Additional information

Funding

This research received no specific grants from the funding agencies.