FDA on Wednesday authorized Novavax's Covid-19 vaccine for emergency use in individuals 18 and older. Officials hope this fourth vaccine option—which doesn't involve mRNA technology—encourages vaccination among holdouts.

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FDA authorizes Novavax vaccine for use in adults

In June, FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted 21-0, with one abstention, to recommend authorizing Novavax's Covid-19 vaccine.

Novavax's vaccine is considered more traditional than Pfizer-BioNTech's and Moderna's mRNA vaccines and Johnson & Johnson's adenovirus vaccine. The Novavax option contains nanoparticles made up of proteins from the surface of the coronavirus. It requires two shots, 21 days apart, and is already authorized for use in several other countries.

In a clinical trial of more than 26,000 adults in the United States and Mexico, researchers found that two doses of Novavax's vaccine had an overall efficacy rate of 90.4% against symptomatic disease and an efficacy rate of more than 78% among adults ages 65 and older. However, experts expect that this level of protection may now be lower now since the vaccine was originally tested against older variants of the coronavirus.

On Wednesday, FDA authorized Novavax's Covid-19 vaccine for emergency use in adults ages 18 and older as a two-shot primary series.

"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 Califf. "Today's authorization offers adults in the United States who have not yet received a COVID-19 vaccine another option that meets the FDA's rigorous standards for safety, effectiveness and manufacturing quality needed to support emergency use authorization."

Although Novavax's vaccine is now authorized by FDA CDC Director Rochelle Walensky needs to recommend it as well before it can become widely available in the United States. According to STAT, CDC's Advisory Committee on Immunization Practices will meet on July 19 and will likely make a recommendation soon after that.

The Biden administration has already purchased 3.2 million doses of the Novavax vaccine, which will be available to states and health care providers following CDC's official recommendation.

Will Novavax's authorization boost vaccination rates?

During VRBPAC's June meeting, Peter Marks, director of FDA's Center for Biologics Evaluation and Research, said he hoped Novavax's protein-based vaccine would help increase vaccination rates among those who have remained hesitant. According to Politico, around 10% of U.S. adults have still not yet received any Covid-19 vaccine.

"We do have a problem with vaccine uptake that is very serious in the United States, and anything we can do to get people more comfortable to be able to accept these potentially lifesaving medical products is something that we feel we are compelled to do," Marks said. "Having a protein-based alternative may be more comfortable for some in terms of their acceptance of vaccines."

However, other health experts say it is unlikely Novavax's vaccine will do much to sway those who remain unvaccinated. According to a recent Morning Consult poll, only 10% of the unvaccinated people surveyed said they would definitely or probably get a protein-based vaccine like Novavax's.

"Optimism that the Novavax vaccine will have a significant impact on the number of unvaccinated Americans is misplaced," said Jason Schwartz, an associate professor at the Yale School of Public Health.

"A small number of people might have been waiting for a vaccine that doesn't involve mRNA technology or lacks the remote links to fetal tissue associated with the development of the currently available vaccines, but the vast majority of those unvaccinated have made their choice for unrelated and deeply ingrained reasons," he added.

According to Schwartz, it would be good if Novavax's vaccine could persuade even 1% to 2% of those who are currently unvaccinated to get their shots, but that was likely "the best-case scenario" for the vaccine. (Herper, STAT, 7/13; Foley/Lim, Politico, 7/13; Robbins/Zimmer, New York Times, 7/13)