Literature analysis of the efficacy of COVID-19 vaccinations

The COVID-19 pandemic is the largest epidemic of the 21st century so far. Over 650 million people have already been infected with the SARS-CoV-2 virus. One of the ways to stop this pandemic, is to vaccinate the population and gain herd immunity. Many different vaccines are being used around the world, with differing efficacy. This review summarizes the 79 publications on the efficacy of the currently existing COVID-19 vaccines. It shows that there are eleven vaccines that have efficacy data published in a PubMed-indexed scientific journal. Most research has been done on the Pfizer/BioNTech BNT162B2 vaccine, and the eleven vaccines generally have a high efficacy in preventing illness. The Pfizer (86%-100%), Moderna (93.2%-94.1%), Sputnik-V (91.6%) and Novavax (~90%) vaccines show the highest efficacy, followed by the Sinovac (83.5%), QazCovid-in 82%) and Covaxin (77.8%) vaccines. The Oxford/AstraZeneca (69% - 81.5%) and Johnson & Johnson (66%) vaccines have lower efficacy in preventing illness. This overview also shows efficacies other than in preventing illness (e.g. asymptomatic, severe illness, hospitalization, death) in some cases. The results also show that the vaccines have specific effects on specific age groups (e.g. adolescents, adults, elderly) and people with diseases (e.g. leukemia, other cancers, HIV). Future research in this area will mostly focus on vaccine efficacy on specific strains of the SARS-CoV-2 virus (such as the Omicron variant) as well as the efficacy of booster vaccinations.