Covid-19 Vaccine and Its Speed and Efficacy
COVID-19 VACCINE SPEED & EFFICACY Background: The global effort to develop a vaccine for coronavirus disease 2019 (COVID-19) has already produced 2 candidates, each requiring 2 doses, with reported efficacies exceeding 90% ( 1 ). The U.S. Food and Drug Administration (FDA) has granted Emergency Use Authorization for both vaccines (Pfizer-BioNTech and Moderna). Their reported efficacies greatly exceed the 50% threshold the FDA cited in a June 2020 guidance document ( 2 ). Additional vaccine candidates at earlier stages of development hold the promise of single dosing, simpler storage requirements, and more rapid immunity after vaccination ( 3 ).