Novavax COVID-19 Vaccine 100% Effective in Phase 3 Clinical Trial

June 15, 2021 - Novavax has announced that its COVID-19 vaccine, NVX-CoV2373, demonstrated 100 percent protection against moderate or severe illness and 90.4 percent efficacy overall in a Phase 3 clinical trial. 

The trial, PREVENT-19, enrolled 29,960 participants across 119 states in the US and Mexico to evaluate the vaccine’s efficacy, safety, and immunogenicity. 

NVX-CoV2373 also elicited 91 percent efficacy among high-risk populations, with 62 COVID-19 cases in the placebo group and 13 COVID-19 cases in the vaccine group.

Overall, the trial met its primary endpoint across all age groups. 

“Today, Novavax is one step closer to addressing the critical and persistent global public health need for additional COVID-19 vaccines. These clinical results reinforce that NVX-CoV2373 is extremely effective and offers complete protection against both moderate and severe COVID-19 infection," Stanley C. Erck, president and chief executive officer at Novavax, said in the announcement. 

"Novavax continues to work with a sense of urgency to complete our regulatory submissions and deliver this vaccine, built on a well understood and proven platform, to a world that is still in great need of vaccines,” Erck continued. 

Notably, no more than one percent of participants in the trial reported one single adverse event term. Injection site pain and tenderness were the most common local symptoms, while fatigue, headache, and muscle pain were the most common systemic symptoms. 

Last July, HHS and the Department of Defense (DoD) announced a 1.6 billion agreement with Novavax to demonstrate commercial-sale manufacturing of NVX-CoV2373.

As part of the funding, the federal government will own the 100 million doses of vaccine.

Experts say the Novavax vaccine could help with the global vaccination effort.

So far, NVX-CoV2373 was found 60 percent effective in preventing mild, moderate, and severe COVID-19 in 94 percent of the study population that was HIV-negative in Novavax’s South African trial. 

And at the end of January, NVX-CoV2373 was 89.3 percent effective in the Phase 3 UK clinical trial and 95.6 percent effective against the original COVID-19 strain found in Wuhan, China. 

The trial enrolled over 15,000 participants between 18 to 84 years of age, including 27 percent over the age of 65. The first analysis was based on 62 cases of COVID-19, of which 56 cases were observed in the placebo group and six cases were observed in the vaccine group.

The trial’s primary endpoint was based on the first confirmed coronavirus case with onset at least seven days after the second vaccination in a COVID-19 negative adult. 

Researchers uncovered efficacy during a period with high transmission and with the new UK variant strain of the virus circulating widely. Specifically, the strain was detected in over 50 percent of confirmed coronavirus cases.

Novavax will file for regulatory authorizations in the third quarter of this year due to the positive trial results in the US and UK, following the final phases of assay validation needed to meet chemistry, manufacturing, and controls requirements.

The company expects 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. 

“PREVENT-19 confirms that NVX-CoV2373 offers a reassuring tolerability and safety profile," Gregory M. Glenn, MD, president of research and development at Novavax, said in the recent announcement. 

"These data show consistent, high levels of efficacy and reaffirm the ability of the vaccine to prevent COVID-19 amid ongoing genetic evolution of the virus. Our vaccine will be a critical part of the solution to COVID-19 and we are grateful to the study participants and trial staff who made this study possible, as well as our supporters, including the U.S. Government,” Glenn continued.