Novavax Recommended as Mix-and-Match Booster Dose After Primary COVID-19 Vaccine Series

In the United States, the Pfizer-BioNTech and the Moderna vaccines ruled as the only authorized COVID-19 boosters. Now, the Centers for Disease Control and Prevention (CDC) have recommended Novavax's COVID-19 vaccine as a mix-and-match booster dose after a primary series of Pfizer-BioNTech, Moderna, or Johnson & Johnson.

This CDC recommendation comes after the Food and Drug Adminsitration (FDA) presented data suggesting the Novavax booster can be administered as a third vaccine dose in adults 18 years and older, 6 months after primary vaccination with a US-approved regimen.

The Novavax COVID-19 Vaccine, Adjuvanted (5 µg recombinant spike protein/50 µg Matrix-MTM adjuvant; NVX-CoV2373) had previously received regulatory authorizations for use in adults ≥ 18 years globally.

After the primary series of COVID-19 vaccines, the public is being encouraged to get a booster, especially with the impending respiratory virus season upon us.

During this week’s ID Week2022 conference investigators provided some late breaking data on Novavax’s COVID-19 vaccine.

Specifically, investigators studied vaccine trial participants of the PREVENT-19 study, which is a phase 3, randomized, observer-blinded, placebo-controlled trial that evaluated the efficacy, safety, and immunogenicity of a primary series of 2 doses of NVX-CoV2373, were eligible to receive a booster dose at least 6 months after the initial vaccination series.

In an ad hoc analysis of 298 participants, the short-term safety and immunogenicity of the booster dose was assessed. “A booster dose induced more robust antibody responses compared with theprimary series in adults ≥ 65 years.” Additionally, higher immune responses against the various Omicron strains including BA1, BA2, and BA5 were seen after the administration of the booster doses than after the primary series in a small subset of 14-18 participants.

The safety profile was favorable. “There was an incremental increase compared to the initial vaccination series in local and systemic reactogenicity, which was transient and mostly mild-to-moderate in intensity. Most unsolicited adverse events were also mild-to-moderate in severity; there were no deaths or treatment-related SAEs and 2/298 booster recipients in this analysis reported unrelated SAEs,” they wrote.

“A single booster dose of NVX-CoV2373 demonstrated a satisfactory safety profile, and high levels of neutralizing, anti-S IgG, and hACE2 inhibition antibody responses against the SARS-CoV-2 prototype Wuhan as well as against the Omicron variant including recently emerged sub-variants,” the investigators wrote.

The results were presented as a late breaking abstract, “Safety and Immunogenicity of a Booster Dose of Novavax COVID-19 Vaccine, Adjuvanted (NVX-CoV2373) in Adults from the PREVENT-19 Trial in the United States,” at IDWeek 2022, held October 19-October 23, 2022 in Washington DC.