Maryland-based biotechnology company Novavax reported on Thursday that its experimental Covid-19 vaccine is more than 96% effective in preventing minor and serious illnesses.
The results are from the company’s Phase 3 clinical trial, which was conducted in the United Kingdom. Novavax testing in the U.S. and South Africa continues, and the company cannot apply for emergency use authorization in the U.S. until American testing is completed.
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“We are very encouraged by the data,” said Stanley Erck, Novavax president and CEO, in a statement.
The UK study included more than 15,000 adults. More than a quarter were 65 or older, an age group that is generally considered to be at greatest risk for Covid-19 complications.
The two-dose vaccine was found to be more than 96 percent effective against previous strains of the virus circulating in the United Kingdom, on a par with vaccines already in use by Moderna and Pfizer-BioNTech.
The effectiveness was slightly lower – around 86 percent – against the more contagious variant B.1.1.7, which was first identified in the UK. The variant has already been detected in almost half of the US states, and the Centers for Disease Control and Prevention predicted that it will be the predominant variant by the end of the month.
The Novavax vaccine was also 100 percent effective against the most severe forms of Covid-19, regardless of the variant – much like the other vaccines in use in the U.S.
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The Biden government has promised enough vaccine to all eligible Americans by the end of May. The expectation is that the goal will be met with the vaccines already available, from Moderna, Pfizer-BioNTech and Johnson & Johnson.
Other vaccines that will ultimately prove successful will be critical to the health and safety of Americans in a post-Covid-19 environment in which viruses can travel from country to country as fast as airplanes.
“The United States is not safe until the vast majority of the rest of the world is vaccinated,” said John Grabenstein, former executive director of medical affairs for vaccines at Merck and a former Department of Defense immunologist.
Novavax also analyzed data from its Phase 2b clinical trial in South Africa, where another variant of SARS-CoV-2 is circulating. The variant, called B.1.351, worries scientists because it appears to decrease the vaccine’s effectiveness. Novavax found that its vaccine was about 50% effective against the variant.
The Novavax vaccine differs slightly from other vaccines in use. All Pfizer, Moderna and Johnson & Johnson vaccines provide instructions for the body to build the coronavirus spike protein, which the immune system learns to recognize and fight. The dose of Novavax ignores the instructions and delivers the protein spike directly to the body.
If approved for use, the Novavax injection can serve as “another shield that we can use to protect ourselves from an unpleasant virus,” said Grabenstein.
More than 98 million doses of vaccines have been administered, according to the CDC, with almost 34 million people fully vaccinated.
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