Novavax announced that its experimental COVID-19 vaccine demonstrated 100% protection against moderate and severe disease and 90.4% efficacy overall in a pivotal phase 3 trial.
The 29,960-person PREVENT-19 trial, conducted in the U.S. and Mexico, also found that the vaccine was similarly effective against newer coronavirus strains, especially the alpha (UK) variant now dominant in the U.S.
The vaccine, called NVX-CoV2373, relies on recombinant nanoparticle technology and Novavax's adjuvant, called Matrix-M, to stimulate an immune response.
According to the Maryland-based drugmaker, there were 77 COVID cases that emerged among participants during the study. Sixty-three of the cases were in people in the placebo group and 14 in the vaccine group. All cases in the vaccine group were mild. There were 10 moderate and four severe cases in the placebo group, demonstrating a vaccine efficacy of 100% against moderate or severe disease, according to Novavax.
The two-dose shot also worked well against coronavirus variants. Against variants of concern and variants of interest, which represented 82% of the trial cases, vaccine efficacy was 93.2% (95% CI: 83.9, 97.1), achieving a key exploratory endpoint of the study.
NVX-CoV2373 also showed success among "high-risk" populations (defined as over age 65, under age 65 with certain comorbidities or having life circumstances with frequent COVID-19 exposure): vaccine efficacy was 91% (95% CI: 83.6, 95.0), with 62 COVID-19 cases in the placebo group and 13 COVID-19 cases in the vaccine group.
The trial results suggest Novavax’s vaccine is on track to become the fourth authorized for use in the U.S.
According to Novavax, the company intends to file for regulatory authorizations in the third quarter, upon completion of the final phases of process qualification and assay validation needed to meet chemistry, manufacturing and controls (CMC) requirements. Pending regulatory approvals, Novavax remains on track to reach manufacturing capacity of 100 million doses per month by the end of the third quarter and 150 million doses per month by the end of the fourth quarter of 2021.
Novavax CEO Stanley Erck said the vaccine is likely to become available first in low- to middle-income countries outside the U.S. through the international Covax initiative, possibly by the end of September.
Read the press release