The Food and Drug Administration on Wednesday approved a Covid-19 vaccine developed by Novavax, a Maryland biotechnology company that received significant federal funding to produce the shot. The vaccine will be a new option for Americans as vaccination rates stagnate.
After two years of development, the vaccine has finally overcome manufacturing difficulties and is the fourth chance to gain approval in the United States. Advisors from the Centers for Disease Control and Prevention will meet next week and are expected to discuss who should receive the Novavax vaccine.
The two-dose vaccine was approved as a primary immunization series for adults, rather than as a booster, which is likely to limit the market initially. The Biden administration said earlier this week it would buy 3.2 million doses, enough to fully vaccinate 1.6 million people in the United States. When announcing the purchase, the government said Novavax was expected to complete its quality testing “in the coming weeks”, a necessary step before the doses are released.
Novavax hopes its vaccine will appeal to people who have rejected injections from Pfizer-BioNTech and Moderna, which use messenger RNA technology. About 22 percent of people in the United States have not received a single dose of Covid vaccine.
Novavax’s vaccine, given in doses three weeks apart, works differently than mRNA vaccines. It triggers an immune response with nanoparticles made up of proteins from the surface of the coronavirus that causes Covid-19. Similar protein-based vaccines have been widely used around the world for decades.
But modest demand for Novavax’s uptake in other rich countries leaves it unclear whether the company’s forecast for the United States will hold up. Only 12.6 million doses of Novavax were distributed in Europe between December, when the vaccine was approved there, and June 30. In contrast, more than a billion doses of Pfizer-BioNTech and Moderna vaccines have been distributed in Europe.
A Morning Consult poll published earlier this month suggests that Novavax may encounter a similar lack of enthusiasm in the United States. Only 10 percent of the unvaccinated people contacted for the poll said they would definitely or probably get a protein-based vaccine.
The license comes with a warning that Novavax’s vaccine is associated with an increased but small risk of forms of heart inflammation known as myocarditis and pericarditis. In their review of Novavax’s data, FDA scientists identified six cases of the adverse reaction in approximately 40,000 trial volunteers.
Moderna and Pfizer-BioNTech’s mRNA vaccines have also been linked to an increased risk of these conditions, but that link has only emerged after they have been widely used. A warning about the risk was also added to their packaging.
Before the pandemic, Novavax was a little-known biotechnology company with several vaccines in the research pipeline, but no approved products. It gained notoriety when Operation Warp Speed, the federal government’s 2020 campaign to develop coronavirus vaccines, singled it out for support. The program initially agreed to pay up to $1.6 billion to fund development of the vaccine and to purchase up to 100 million doses of the injection.
But due to a series of production delays, the injection was not available for the first wave of vaccinations in the United States in early 2021.
Production problems continue to haunt the company. Even after an FDA advisory committee recommended that the vaccine be approved in early June, it took weeks to give it the green light as it took more time to sign Novavax’s manufacturing process. The Serum Institute of India, the world’s largest vaccine producer, produces Novavax’s vaccine.
In a number of clinical studies, Novavax found that Novavax’s vaccine provided high protection against symptomatic infection. But the original formulation probably isn’t as effective against the Omicron variant, which surfaced in November and evaded some of the protection offered by authorized vaccines from other companies.
Novavax is developing new versions of its vaccine targeting Omicron and its highly contagious sub-variants. Preliminary data from laboratory and animal studies indicate that a booster injection targeting a prior Omicron subvariant, BA.1, generates strong immune responses against the virus. The company says it expects results from a clinical trial of that injection in September, with doses due in the final three months of this year.
The company says it plans to accelerate its research on shots specifically tailored to two newer versions of Omicron, known as BA.4 and BA.5.
Trials have also shown that Novavax’s injection works well as a booster, and the company is expected to seek approval for boosters soon. The company may then be able to attract vaccinated people who want to switch to a new option to protect against new variants.
John Moore, a virologist at Weill Cornell, said he thought Novavax was an excellent vaccine, but wasn’t convinced that an Omicron-based booster would provide much additional protection compared to the original version. “There’s too little information,” he said.
dr. Moore speculated that some people might switch to Novavax for a booster this fall because it caused relatively few cases of pain, fatigue and other transient side effects in clinical trials. That was his experience as a volunteer in one of Novavax’s trials. “The only way I could tell the next day which arm I had the needle in was the band-aid,” he said.
If Novavax is authorized for a booster, Dr. Moore like to come back for another shot, he said, “Sometime in the fall I’ll have another dose, and it would be Novavax.”
