Results of clinical studies of the Novavax vaccine show that it is safe and prevents COVID-19


The results of a Phase 3 clinical trial (PREVENT-19) enrolling 29,960 adult volunteers in the United States and Mexico show that Novavax's investigational vaccine known as NVX-CoV2373 demonstrated 90.4% efficacy in preventing symptomatic COVID-19 disease. It also demonstrated 100% protection against moderate and severe disease. In people at high risk of developing complications from COVID-19 (people 65 years of age or older, and people under age 65 with certain comorbidities or with likely regular exposure to COVID-19), the vaccine showed 91.0% efficacy in preventing symptomatic COVID-19 disease.

Safety data indicate that the investigational vaccine was generally well tolerated. Mild to moderate pain and tenderness at the injection site were the most common local symptoms among participants. The most common systemic symptoms were fatigue, headache, and muscle pain, and lasted an average of less than two days.

The PREVENT-19 trial began in late December 2020, and participants were randomly assigned to receive two injections, 21 days apart, of the investigational vaccine or a placebo. 

NVX-CoV2373 is a subunit vaccine made from a stabilized form of the coronavirus spike protein, using recombinant protein nanoparticle technology. The vaccine also contains a patented adjuvant, MatrixM™. NVX-CoV2373 comes in liquid form and can be stored and distributed at temperatures between 2°C and 8°C (36°F and 46°F). 

In May 2021, the PREVENT-19 trial was expanded to evaluate the safety, efficacy, and immunogenicity of NVX-CoV2373 in adolescents ages 12 to 17; the recruitment of 2,248 participants has recently been completed. 


  • Share: