Moderna vaccine shows 94.1% efficacy in a Phase 3 clinical trial
There were no safety issues found and the side effects have been mild, though more research is needed on its effect on transmission.
, Associate Editor
The investigational vaccine known as mRNA-1273 was 94.1% effective in preventing symptomatic COVID-19, according to preliminary results from a Phase 3 clinical trial reported in
The New England Journal of Medicine. The vaccine also demonstrated efficacy in preventing severe COVID-19, and investigators identified no safety concerns or evidence of vaccine-associated enhanced respiratory disease (VAERD).
The vaccine was codeveloped by Massachusetts-based Moderna and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. Moderna and NIAID previously shared initial results from the COVE trial. On Dec. 18, 2020, the FDA issued an emergency use authorization allowing Moderna to make the vaccine available for the prevention of the coronavirus in adults in the U.S.