PHOENIX – Three COVID-19 vaccines have made their way through trials in the United States since December. Vaccines from Pfizer and Moderna passed testing standards set by the Food and Drug Administration with the hope that millions will be distributed across the country in the coming months. The third vaccine, from AstraZeneca, is in the final stage of clinical trials.
Although all three have been held to the same rigorous standards, each vaccine is different in makeup and how it fights the coronavirus that causes COVID-19. The Pfizer and Moderna vaccines need to be kept at very low temperatures, while the AstraZeneca vaccine can last up to six months if stored in 38 to 46 degree temperatures. All three require a second dose several weeks later for maximum protection.
The efficacy of the vaccines also varies. The Pfizer and Moderna vaccines have been more than 90% effective in protecting against the coronavirus in clinical trials. AstraZeneca’s, however, fell to 62% in its second dose during trials.