Novavax Reports on Two Vaccine Efficacy Studies

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Novavax’s COVID-19 vaccine is 90.4% effective and maintains efficacy when administered with an influenza vaccine.

Novavax announced on June 14, 2021, results from two studies of is recombinant nanoparticle protein-based COVID-19 vaccine; in a large study, the vaccine candidate demonstrated 90.4% efficacy overall and in a second small study, the efficacy showed only a modest decrease when co-administered with a seasonal influenza vaccine.

A large study of the NVX-CoV2373 vaccine enrolled nearly 30,000 participants in the United States and Mexico to evaluate efficacy, safety, and immunogenicity. The results showed an overall efficacy of 90.4%; 63 cases of COVID-19 were observed in the placebo group and 14 cases, defined as mild, occurred in the vaccine group. The company reported a vaccine efficacy of 100% against moderate or severe disease and success among high-risk populations.

Novavax also reported on June 14, 2021, data from a co-administration study of NVX-CoV2373 and an approved influenza vaccine, which suggests simultaneous vaccination for COVID-19 and influenza may be a viable strategy.

As part of the company’s Phase III clinical trial of NVX-CoV2373 in the United Kingdom, approximately half the 431 participants who received the Seqirus influenza vaccine were also vaccinated with NVX-CoV2373; the rest received a placebo. The study showed that vaccine efficacy appeared to be preserved in those receiving both vaccines compared to those vaccinated with NVX-CoV2373 alone, the company reports. Few mild side effects such as pain at the injection site were reported.


Vaccine efficacy in the sub-study was 87.5% while efficacy in the main study was 89.8% against SARS-CoV-2. The company also reported that immunogenicity of the influenza vaccine was preserved with concomitant administration.

Novavax said that it intends to file for regulatory authorizations in the third quarter of 2021 and, if approved, is scheduled to manufacture 100 million doses per month by the end of the third quarter and 150 million doses per month by the end of the fourth quarter of 2021.

Source: Novavax