The New England Journal of Medicine published the results of a phase 3 clinical trial for a COVID-19 vaccine candidate named NVX-CoV2373, and the results bode well so far.
Researchers conducted a phase 3, randomized, observer-blind, placebo-controlled trial in the United States and Mexico during the first half of 2021 to evaluate the efficacy and safety of this vaccine. 29,9582 participants were divided into groups that received the vaccine (19,714) and groups that received placebo (9,868). Each group received two doses 21 days apart.
Over three months, 77 cases of COVID-19 were noted, with 63 of them among the placebo group and 14 of them among the vaccine group. Ten moderate and four severe cases of COVID-19 were noted, all of them in the placebo group.
Regarding safety, commonly reported adverse events amongst the vaccine group included injection-site pain, headache, myalgia, fatigue, and malaise. Injection-site pain lasted two days or less on average, while other adverse events lasted one day on average. In both scenarios, these events were more common after the second vaccine dose. Severe local reactions were infrequent but more common amongst the vaccine group.
While various other non-authorized vaccine candidates have been tested by researchers across the nation, this is one of the few additional candidates that has tested well in phase 3 trials conducted by American researchers, and could potentially see authorization in the U.S.