HealthDay News — The adjuvanted, recombinant spike protein nanoparticle vaccine, NVX-CoV2373, is effective for the prevention of COVID-19 in adults, according to a study published online December 15 in the New England Journal of Medicine.

Lisa M. Dunkle, MD, from Novavax in Gaithersburg, Maryland, and colleagues conducted a phase 3 trial to evaluate the safety of NVX-CoV2373 in adults in the United States and Mexico. Between December 27, 2020, and February 18, 2021, a total of 29,949 participants were randomly assigned in a 2:1 ratio to receive two doses of either NVX-CoV2373 or placebo, administered 21 days apart.

The researchers found that among vaccine and placebo recipients, the incidence of COVID-19 was 3.0 and 34.0 cases per 1000 person-years, respectively, for a vaccine efficacy of approximately 90%. In the placebo group only, there were 10 moderate and 4 severe cases, for a vaccine efficacy of 100% against moderate-to-severe disease. Most sequenced viral genomes (79% of 61) were variants of concern or interest, mainly B.1.1.7 (alpha). Vaccine efficacy was 92.6% against any variant of concern or interest. Reactogenicity was mainly mild-to-moderate and transient, but occurred more often among NVX-CoV2373 than placebo recipients and after the second dose versus the first dose.

“The efficacy of NVX-CoV2373 in preventing moderate-to-severe COVID-19 as well as any symptomatic COVID-19 in people at high risk for acquisition and complications of COVID-19 will make this vaccine a valuable tool in controlling the pandemic and its most serious health and economic consequences,” the authors write.

Several authors disclosed financial ties to pharmaceutical companies, including Novavax, which manufactures the NVX-CoV2373 vaccine and funded the study.

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