Novavax announced that Swissmedic, the Swiss Agency for Therapeutic Products, has expanded its temporary authorization of Nuvaxovid (NVX-CoV2373) COVID-19 vaccine in Switzerland for active immunization to prevent coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in adolescents aged 12 through 17 and as a heterologous and homologous booster dose for adults aged 18 and older.
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The authorization for adolescents aged 12 through 17 is based on data from the ongoing pediatric expansion of the Phase 3 PREVENT-19 trial of 2,247 adolescents aged 12 through 17 years across 73 sites in the U.S. to evaluate the safety, effectiveness (immunogenicity), and efficacy of Nuvaxovid. In the pediatric expansion, Nuvaxovid achieved its primary efficacy 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.
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 authorization for the booster dose in adults aged 18 and older is supported by data from Novavax' Phase 2 trial conducted in Australia, from a separate Phase 2 trial conducted in South Africa, and from the UK-sponsored COV-BOOST trial.
As part of the Phase 2 trials, a single booster dose of Nuvaxovid was administered to healthy adult participants approximately six months after their primary two-dose vaccination series of Nuvaxovid.
The third dose produced increased immune responses comparable to or exceeding levels associated with protection in Phase 3 clinical trials. In the COV-BOOST trial, Nuvaxovid induced a meaningful antibody response when used as a heterologous third booster dose.
In the Novavax-sponsored trials, following the booster, local and systemic reactions had a median duration of approximately two days.
The incidence of Grade 3 or higher events remained relatively low.
Safety reporting of reactogenicity events showed an increasing incidence across all three doses of Nuvaxovid, often seen with increased immunogenicity.
Medically attended adverse events, potentially immune-mediated medical conditions, and severe adverse events occurred infrequently following the booster dose and were balanced between vaccine and placebo groups. ■