The U.S. Food and Drug Administration (FDA) has granted emergency authorization to Novavax’s Covid-19 vaccine, providing a more traditional protein-based alternative to the three mRNA-based vaccines now available. The authorization covers only the initial two shots; the vaccine is not yet approved for boosters or for use in children, per the Washington Post’s Carolyn Y. Johnson.
Currently, about a third of Americans—or 100 million individuals—are unvaccinated.
“Having a protein-based alternative may be more comfortable for some in terms of their acceptance of vaccine,” said Peter Marks, the FDA’s director of the Center for Biologics Evaluation and Research, during a meeting of the agency’s independent expert committee, per The Verge’s Nicole Wetsman
The Novavax vaccine works similar to how vaccines against shingles and influenza work, reports the Post. It delivers coronavirus spike protein cells to the body, which invokes an immune response. It also contains an adjuvant, which boosts the immune response to the vaccine, per a statement from the FDA.
"Protein-based vaccines like this have quite a long history—from hepatitis to meningococcal B, to HPV," Novavax's chief medical officer Filip Dubovsky told BBC News in April. "I think some people are reassured by the decades of safety profiles which are based on this technology."
The shots were tested in a trial in the United States and Mexico. Almost 20,000 participants received the vaccine and about 10,000 got a placebo. Over a period of three months, 14 cases of Covid-19 were noted among vaccine recipients and 63 among those who got the placebo, representing a 90.4 percent efficacy. But the vaccine was tested before both the Delta and Omicron variants were circulating widely, per The Verge, so the efficacy is expected to decrease.
“The Novavax data was pretty significant,” Wayne A. Marasco, an FDA adviser and professor of cancer immunology and virology at Dana-Farber Cancer Institute, tells the Post. “I wonder if we’re not witnessing some of the limitation that there may be [of] the mRNA vaccines. Yes, they were first out of the gate. But they don’t appear to have that breadth of protection.”
The protein-based vaccine was initially regarded as a Covid-19 vaccine front-runner, and received funding from the federal government during Operation Warp Speed. But manufacturing problems delayed testing of the shots, and even after the vaccine was shown effective in trials, manufacturing issues held up submission to the FDA for approval, per The Verge. In June, FDA advisors recommended the vaccine for emergency use in adults.
Despite enthusiasm from some, health professionals aren't sure whether the new approval will spur vaccine skeptics to get their shots. A recent Morning Consult poll found that 77 percent of unvaccinated adults said they wouldn’t get a traditional protein-based COVID-19 shot if one were available.
“Optimism that the Novavax vaccine will have a significant impact on the number of unvaccinated Americans is misplaced,” Jason Schwartz, an associate professor at the Yale School of Public Health, tells STAT’s Matthew Herper. “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.”
The shots will need approval from the CDC before they can be administered, but the Biden administration has already announced it would buy 3.2 million doses.