Research Developments on the World’s Prominent COVID-19 Vaccines

May 19, 2021

Researchers around the world are creating and testing close to 100 vaccines in an effort to combat the novel coronavirus. The following Vaccine Comparison Chart provides a breakdown of leading vaccines that have shown promise through pre-clinical data, completed Phase 1/2/3 clinical trials, and have been authorized for emergency use.

Preclinical data is collected when testing a vaccine on cells and animals. If an immune response is detected, the study moves forward as a Phase 1 safety trial by testing the safety of the vaccine on a select number of people (typically around 20-80 people).

If the dosage is deemed safe and effective, the trial progresses to a Phase 2 expanded trial, in which hundreds of people receive the vaccine. At this stage, participants are split into groups to observe the vaccine’s efficacy and safety across a spectrum of ages.

A Phase 3 efficacy trial tests for vaccine efficacy against volunteers who receive a placebo. Thousands of participants are included in the trial, and an efficacy rate is determined for the vaccine against a virus.

Due to the nature of the coronavirus, some vaccine trials underwent combined phases (e.g. Phase 1/2) in order to accelerate development.