On Nov. 29, 2022, Novavax announced that the World Health Organization had issued an updated Emergency Use Listing for Nuvaxovid (NVX-CoV2373) COVID-19 vaccine for active immunization to prevent coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a primary series of two doses in adolescents aged 12 through 17 and as a booster in adults aged 18 and older.

Preliminary safety data from the pediatric expansion showed the vaccine to be generally well-tolerated. Serious and severe adverse events were low in number and balanced between vaccine and placebo groups, and not considered related to the vaccine. Local and systemic reactogenicity was generally lower than or similar to adults, after the first and second dose. The most common adverse reactions observed were injection site tenderness/pain, headache, myalgia, fatigue, and malaise. There was no increase in reactogenicity in younger (12 to <15 years old) adolescents compared to older (15 to <18 years old) adolescents. No new safety signal was observed through the placebo-controlled portion of the pediatric expansion.

The updated EUL for Nuvaxovid as a primary series in adolescents aged 12 through 17 was based on data from the ongoing pediatric expansion of the Phase 3 PREVENT-19 trial of 2,232 adolescents aged 12 through 17 years across 75 sites in the U.S., to evaluate the safety and effectiveness of Nuvaxovid. In the pediatric expansion, Nuvaxovid achieved its primary effectiveness endpoint and demonstrated 80% clinical efficacy overall at a time when the Delta variant was the predominant circulating SARS-CoV-2 strain in the U.S.