Novavax announced that NVX-CoV2373, its recombinant nanoparticle protein-based Covid-19 vaccine, achieved its primary effectiveness endpoint in the paediatric expansion of its PREVENT-19 pivotal Phase 3 trial and demonstrated 80% efficacy overall at a time when the Delta variant was the predominant circulating strain in the U.S. The study enrolled 2,247 adolescents aged 12 through 17-years across 73 sites in the U.S. to evaluate safety, effectiveness (immunogenicity), and efficacy, with an emphasis on ensuring well balanced racial and ethnic representation among participants.

"We are encouraged by the results in this adolescent population given the ongoing need for alternative vaccine options for Covid-19," said Filip Dubovsky, MD, Chief Medical Officer, Novavax. "We believe the Novavax vaccine offers a differentiated technology and option for this younger population given its established protein-based technology already used in other vaccines, and the positive responses demonstrated against variants."

The primary PREVENT-19 pivotal Phase 3 trial conducted in adults aged 18 years and older, results of which were published in The New England Journal of Medicine (NEJM), enrolled approximately 30,000 participants in the U.S. and Mexico. NVX-CoV2373 achieved 90.4% efficacy overall and demonstrated a reassuring safety and tolerability profile. Serious and severe adverse events in adults were low in number and balanced between vaccine and placebo groups.

NVX-CoV2373 has not yet been authorized in the adolescent population. Novavax expects to submit its regulatory filings for a pediatric indication in adolescents aged 12 through 17-years to global regulatory authorities during the first quarter of 2022. Novavax also expects to initiate additional studies globally evaluating younger age groups during the second quarter of 2022.