On Sept. 1, 2022, Novavax announced that Nuvaxovid (NVX-CoV2373) COVID-19 vaccine had been recommended for expanded conditional marketing authorization (CMA) in the European Union (EU) as a homologous and heterologous booster for active immunization to prevent coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for adults aged 18 and older.

The CHMP recommendation was based on 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 robust antibody response when used as a heterologous third booster dose.

In the Novavax-sponsored trials, following the booster, local and systemic reactions were generally short-lived with 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, reflecting the increased immunogenicity seen with a third dose. Medically attended adverse events (AE), potentially immune-mediated medical conditions, and severe AEs occurred infrequently following the booster dose and were balanced between vaccine and placebo groups.

The European Commission (EC) previously granted CMA for Nuvaxovid in adults aged 18 and older in December 2021. Additionally, the EC granted CMA for Nuvaxovid to prevent COVID-19 in adolescents aged 12 through 17 in July 2022.