A key federal advisory committee voted Tuesday to recommend emergency authorization of a new COVID-19 vaccine developed by the Maryland biotechnology company Novavax, making it the fourth inoculation against the disease that has killed over 1 million Americans to clear that hurdle in the U.S.
The decision comes at a time when two COVID-19 vaccines, made by Pfizer/BioNTech and Moderna, have already received full approval by the Food and Drug Administration and more than three-quarters of Americans ages 18 and older are already fully vaccinated. However, approximately 27 million adults remain unvaccinated according to recent CDC data.
How effective is the new vaccine?
After reviewing the two-dose Novavax vaccine’s safety and efficacy data, the FDA’s panel of experts approved it for emergency use in adults ages 18 and older, recommending that doses be spaced three weeks apart.
In clinical trials, the Novavax vaccine was found to be 90% effective at preventing mild, moderate and severe COVID-19. According to FDA briefing documents published ahead of Tuesday’s meeting, the most common side effects include injection site pain, fatigue, headache and muscle pain.
Some of the FDA experts, however, raised concerns that the vaccine may lead to myocarditis, an inflammation of the heart muscle, that has been observed in some patients, particularly young men, who have received COVID-19 vaccines. During the Novavax vaccine trials, among nearly 30,000 vaccine recipients, just four cases of myocarditis were observed.
“We believe that the totality of the clinical evidence here is not enough to establish an overall causal relationship with the vaccine,” Novavax chief safety officer Denny Kim told the FDA committee, adding that the company is closely monitoring such cases of myocarditis and gathering more data from its clinical trials as well as the real-world use of its vaccine, which according to the Washington Post, has already been authorized in more than 40 countries.
Does the Novavax vaccine protect against new coronavirus variants?
Another concern that was brought up by some members of the FDA committee is that the Novavax vaccine was designed to target the original strain of the coronavirus, and there’s currently no data available on how it does against the Omicron variant, or others now spreading quickly across the U.S.
“One challenge is that the trial occurred before the more transmissible Delta and Omicron variants, so it is probably safe to assume that the effectiveness is somewhat lower given the high contagiousness of these current variants,” Dr. Lucy McBride, a Yahoo News Medical Contributor said following the FDA decision.
Novavax chief medical officer Filip Dubovsky admitted the company doesn’t yet have efficacy data against Omicron or other recent mutations, but he said their vaccine is likely to protect against the new variants as well. “It’s factual that we don’t have efficacy data against Omicron. What we do have is a technology that we think generates a broad immune response, demonstrated against a broad array of variants,” Dubovsky said.
McBride says the new vaccine will be an important tool to continue to fight the virus. “It’s important to remember that any vaccine is better than no vaccine, particularly when it comes to high-risk individuals,” she told Yahoo News.
Even though at the moment Novavax only sought emergency authorization for the primary series of their vaccine, the company has said it plans to seek expanded authorization in the future for use of the shot in adolescents and as a booster.
How is the Novavax vaccine different from other COVID-19 vaccines?
The Novavax vaccine uses an older and more conventional technology called recombinant protein, which has been used before in other vaccines targeting influenza, shingles, human papillomavirus (HPV) and hepatitis B.
The mRNA vaccines, such as those manufactured by Pfizer and Moderna, rely on messenger RNA to instruct human cells to produce copies of the COVID-19’s spike protein, which is the part of the virus that helps it attach to cells.
The Novavax vaccine technology, on the other hand, produces copies of the virus’s spike protein outside the human body. These lab-made spike copies, which can’t replicate or cause COVID, are then inserted into the body in a nanoparticle made of a lipid. The body then produces an immune response that helps protect against the virus. In addition, the Novavax vaccine uses an ingredient called an adjuvant, which helps generate a broader immune response against the virus.
Following Monday’s FDA committee vote, some members said the new vaccine offered a great opportunity to see how the different COVID-19 inoculations compared to one another over the long term.
“I see this as an opportunity to widely vaccinate people with a protein vaccine and to compare it with mRNA vaccines, which are relatively new technology,” Dr. Jay Portnoy, a committee member said. “The vaccine deserves an opportunity to be given and studied and used by individuals who wish to use this vaccine,” he added.
When will the vaccine be made available in the U.S?
Although it is not obliged to do so, the FDA usually follows the committee’s recommendations. Now that this vote is in, the agency could make a final determination on whether to authorize the vaccine as soon as this week. However, the vaccine will not be available to the public until the CDC also signs off on the shots. This usually occurs after a CDC vaccine expert panel, the Advisory Committee on Immunization Practices, also meets to review the vaccine’s safety and efficacy. That meeting, however, has not been scheduled yet.