Methodical and Immunological Insights of Prime COVID-19 Vaccines

Abstract

Vaccines' discovery, manufacturing, and distribution have been on a historic uptick in response to this worldwide COVID-19 pandemic. A handful of vaccines have been approved on an emergency basis after passing minimal clinical trials. There are voids in the existing body of research and the published body of work on phase II and III clinical trial outcomes, efficacy, and recently developed side effects of the approved COVID-19 vaccines. Furthermore, the immunological and methodological insights of successful vaccinations are still unpopular and are not publicly reported. We have attempted to review some major classes of COVID-19 vaccines, namely inactivated viral particle vaccine (BBV152 - Covaxin), mRNA vaccines (BNT162b2 - Pfizer and mRNA-1273- Moderna), viral vector vaccines (Gam-COVID-Vac-Sputnik and ChAdOx1-S-Astrazeneca) and protein subunit vaccine (NVX-CoV2373-Novavax) and discuss their methodological and immunological formulations. This review intends to address the existing literature's gaps and limitations and the vaccine’s safety, efficiency, and effectiveness profiles. This report, by accumulating and comparing the existing publicly available literature and datasheets of the vaccines, concludes that the efficacy of the vaccinations has been found to be 81% for BBV152 (COVAXIN), 94.5% for BNT162b2 (Pfizer), 94.5% for mRNA-1273 (Moderna), 91.6% for Gam-COVID-Vac (Sputnik V), 62–90% for ChAdOx1-S (AstraZeneca), and 96.4% for NVX-CoV2373 (Novavax), demonstrating their efficacy in lowering the severity and frequency of SARS-CoV-2 infection. We conclude that while the commercially approved vaccines have a few limitations regarding clinical trials and side effects, they provide immunity with efficacy ranging from 81% to 96.4% against COVID-19.