FDA Authorizes Novavax COVID-19 Vaccine for Adults, the First Protein-based Vaccine Available in US

The US Food and Drug Administration (FDA) issued an emergency use authorization (EUA) for the Novavax COVID-19 Vaccine, Adjuvanted (NVX-CoV2373), making it the first protein-based COVID-19 vaccine available in the US.

The FDA said in a Wednesday press release that the 2-dose COVID-19 vaccine “has met the statutory criteria for issuance of an EUA” for persons aged ≥18 years and that data show the benefits of NVX-CoV2373 outweigh its risks.

“Authorizing an additional COVID-19 vaccine expands the available vaccine options for the prevention of COVID-19, including the most severe outcomes that can occur such as hospitalization and death,” said FDA Commissioner Robert M. Califf, MD, in the press release.

NVX-CoV2373 is administered as a 2-dose primary series given 3 weeks apart and contains the SARS-CoV-2 sike protein and Novavax’s saponin-based Matrix-M™ adjuvant. The adjuvant has demonstrated a well-tolerated effect by, “stimulating the entry of antigen-presenting cells into the injection site and enhancing antigen presentation in local lymph nodes, boosting immune response,” according to the company’s statement on the EUA.

“After a comprehensive analysis and evaluation of the data, and assessment of the manufacturing processes and information, as well as input from the FDA’s committee of external independent advisors, the FDA’s medical and scientific experts have determined that the vaccine meets the FDA’s high standards for safety and effectiveness for emergency use authorization,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, in the agency’s statement.

The vaccine was assessed in the ongoing randomized, blinded, placebo-controlled clinical trial PREVENT-19 in the US and Mexico among persons aged ≥18 years with no evidence of a past SARS-CoV-2 infection through 6 days after receiving the second vaccine dose. Approximately 17 200 participants received NVX-CoV373 and about 8300 received saline placebo.

Overall, NVX-CoV373 was 90.4% effective in preventing mild, moderate, or severe COVID-19, with 17 cases of COVID-19 occurring in the vaccine arm and 79 cases in the placebo arm. No cases of moderate or severe COVID-19 were reported in persons who received NVX-CoV373, compared with 9 cases of moderate COVID-19 and 4 cases of severe COVID-19 observed in the placebo cohort. In participants aged ≥65 years, the vaccine was found 78.6% effective.

The trial also assessed the safety of NVX-CoV373 in approximately 26 000 participants in the vaccine cohort and 25 000 persons who received placebo. Adverse events were predominantly mild-to-moderate and transient, and occurred more frequently among NVX-CoV2373 recipients than among placebo recipients. The most common side effects reported by vaccine recipients included pain/tenderness, redness and swelling at the injection site, fatigue, muscle pain, headache, joint pain, nausea/vomiting, and fever.

The FDA noted that PREVENT-19 was conducted prior to the emergence of the delta and omicron variants.

“The American public can trust that this vaccine, like all vaccines that are used in the United States, has undergone the FDA’s rigorous and comprehensive scientific and regulatory review,” stated Marks.

The FDA said it expects Novavax to continue clinical trials to obtain additional safety and efficacy data and pursue approval.