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Results from the Novavax phase III clinical trial for its COVID-19 vaccine show an overall efficacy of 90%, and demonstrate 100% protection against moderate and severe disease. The study enrolled 29,960 participants across 119 sites in the U.S. and Mexico, including the UNC School of Medicine and UNC Medical Center.


CHAPEL HILL, NC – Results released by Novavax on Monday, June 14 reveal another promising vaccine candidate for the world’s battle against COVID-19. UNC joined the Novavax phase III clinical trial at the end of 2020, with Cindy Gay, MD, associate professor in the Division of Infectious Diseases, as the principal investigator.

“It is critical to continue our research on COVID-19 vaccines because we aren’t at the finish line yet. We need multiple options in order to be able to provide vaccines to people in the U.S. and across the globe in a timely manner,” Gay, a member of the UNC Institute for Global Health and Infectious Diseases, said when the trial began.

Novavax says its recombinant protein vaccine, given in two doses three weeks apart, proved to be 90% effective overall, making it comparable to mRNA vaccines produced by Pfizer-BioNTech and Moderna. Looking closer at the data, the vaccine was 91% protective in people deemed to be at high risk of a bad outcome from a COVID-19 infection, and 93% protective against predominantly circulating variants of concern.

“These results are incredibly promising,” said Joe Eron, MD, Herman and Louise Smith Distinguished Professor of Medicine, Chief of the Division of Infectious Diseases, and co-investigator for the UNC Novavax trial. “The data demonstrate that the vaccine is highly effective and also has a high bar for safety.”

The Novavax vaccine is a protein-based vaccine, using a DNA replica of the spike protein on the surface of SARS-CoV-2, the virus that causes COVID-19. The vaccine contains an adjuvant molecule to further enhance the immune response. The Moderna and Pfizer mRNA vaccines have been shown to be effective and safe but require sub-zero temperatures to remain stable before injection, which significantly limits the speed and geographic scope of current vaccine distribution. The Novavax vaccine requires only refrigeration to remain stable.

“We need a variety of vaccines available since different vaccines may show significant differences in efficacy and longevity of protection. The only way that we learn this critical information is to continue our research,” said Gay, who is also the principal investigator of the ongoing Novavax clinical trial for adolescents at UNC.

Novavax expects to share further details of its adult trial results as additional data become available. Full trial data will be released at a later date via preprint servers and will be submitted to peer-reviewed journals for publication.

See more information about Novavax’s vaccine here.