Novavax's COVID vaccine finally gets FDA clearance for use in unvaccinated

Enlarge / Empty vials of Novavax Inc. Nuvaxovid COVID-19 vaccine laid out at the Tegel Vaccine Center in Berlin, Germany, Monday, March 7, 2022. Getty | Bloomberg

The United States Food and Drug Administration on Wednesday issued long-awaited clearance for Novavax's COVID-19 vaccine. This is the fourth COVID-19 vaccine to gain authorization in the United States, but it is the first to use a more conventional protein subunit design.

For now, the two-dose vaccine is primarily for the roughly 72 million Americans who have yet to receive a dose of a COVID-19 vaccine. The FDA emergency use authorization only allows its use as a primary series, not as a booster for those already vaccinated. Although Novavax is expected to seek recall clearance later, the company and the FDA are hopeful that the traditional vaccine formulation will now appeal to vaccine hesitants, especially as BA.5 sweeps the country.

Some consider the protein subunit design of the vaccine a more proven design compared to the novel mRNA-based platform used in leading COVID-19 vaccines made by Pfizer-BioNTech and Moderna. While mRNA-based vaccines made their public debut during the pandemic, protein subunit vaccines were already being used against a variety of diseases, including hepatitis B, influenza, whooping cough (whooping cough) and meningococcal infections.

To fight COVID-19, the Novavax vaccine directly delivers the SARS-CoV-2 spike protein, which is manufactured on a large scale in insect cells. The vaccine also includes an adjuvant, which is an additive that enhances immune responses. In this case, the adjuvant involves saponin extracts from the Chilean soap tree previously used in FDA-approved vaccines.

Long-awaited option

At a meeting of FDA advisers last month, the agency's lead vaccine regulator, Peter Marks, expressed the need for more vaccine options in the United States. “We have a vaccination problem that is very serious in the United States, and anything we can do to make people more comfortable accepting these potentially life-saving medical products is something we feel compelled to do. .,” Marc said. As such, many experts were eager to see the Novavax vaccine licensed. But the vaccine, which has been in development for two years, has been significantly delayed by a series of manufacturing setbacks that were only recently resolved.

Yet at the June meeting, FDA advisers voted almost unanimously in favor of FDA clearance of the vaccine. In a large trial of more than 25,000, the vaccine appeared to be 90.4% effective against COVID-19, although the trial was conducted before the delta and omicron variants emerged. The vaccine also appears to be generally safe, although it comes with an increased risk of myocarditis and pericarditis (inflammation of the heart and surrounding tissues). Ultimately, 21 of 22 FDA advisers voted in favor of clearance, while one expert abstained, citing lack of variant-specific efficacy data.

"Today's approval provides 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, efficacy and manufacturing quality necessary to support emergency use authorization. COVID-19 vaccines remain the best preventive measure against serious illness caused by COVID-19," FDA Commissioner Robert Califf, in a statement. "And I encourage anyone who is eligible, but has not yet had a COVID-19 vaccine, to consider getting it."

Authorization lands as federal authorities redouble efforts to boost vaccination rates, which have largely stagnated. Last week, Novavax announced that the US government had signed an agreement to purchase 3.2 million doses. But, before Novavax's shots can begin to take up arms, the Centers for Disease Control and Prevention will no longer have...