After Adcomm’s Vaccine Recommendation, Can Novavax Make a Covid Comeback?

Pictured: Syringe pulling vaccine from a vial / Adobe Stock, weyo

Pictured: Syringe pulling vaccine from a vial / Adobe Stock, weyo

Thursday, the FDA’s Vaccines and Related Biological Products Advisory Committee unanimously recommended that for the upcoming vaccination campaign, current COVID-19 shots should be updated to cover the latest XBB Omicron subvariant.

In particular, the panel of independent experts recommended focusing on subvariant XBB.1.5, the most dominant subvariant in circulation right now. According to February 2023 data from the Centers for Disease Control and Prevention, XBB.1.5 accounts for more than 65% of all new COVID-19 cases in the U.S.

The advisory committee also recommended a monovalent shot for the coming immunization campaign, focusing specifically on Omicron and its subvariants. The current standard shots are bivalent, meaning they target both Omicron and the original coronavirus strain.

Thursday’s 21–0 vote, with no abstentions, could set the stage for a Novavax comeback. The company was poised to be one of the biggest winners of the COVID-19 pandemic. However, its coronavirus vaccine Nuvaxovid was hamstrung by several challenges, including safety concerns such as myocarditis and severe allergic reactions.

In October 2020, Novavax also announced that it had encountered manufacturing difficulties, which slowed down its Phase III trial for Nuvaxovid and delayed the vaccine’s launch.

The FDA eventually granted Nuvaxovid emergency use authorization in July 2022, but by then, much of the U.S. market had already been captured by its chief competitors Pfizer/BioNTech and Moderna.

Falling far behind in the COVID-19 vaccine race was difficult for Novavax’s business. In its full-year 2022 financial report, the company told investors that it might not be able to keep its operations going beyond February 2024.

Novavax provided a more positive outlook in its first-quarter 2023 report when it revealed a sweeping cost-cutting plan and an optimistic 2023 forecast. Novavax’s survival plan rests on its protein-based coronavirus shot, its only product, of which it hopes to release an updated version in time for the upcoming fall vaccination season.

In a statement after the advisory committee meeting, Novavax CEO John Jacobs said that the Maryland biotech has been developing its updated vaccine candidate in cooperation with the FDA, World Health Organization and other global regulators.

“We believe we are in a better position to offer an alternative vaccine choice for individuals worldwide,” Jacobs said.

In its presentation during the committee meeting, Novavax unveiled data showing that its monovalent XBB.1.5-targeting vaccine induces a strong neutralizing response not only against the XBB.1.5 subvariant but also against XBB.1.16 which is slowly gaining ground globally.

Dubbed arcturus, XBB.1.16 was responsible for 15% of new COVID-19 cases in the two-week period leading up to May 26, according to the Centers for Disease Control and Prevention, U.S. News reported. 

Novavax’s candidate also blocked the spike protein of the XBB.2.3 subvariant from binding to its counterpart human ACE-2 receptor, which could be indicative of prophylactic activity against this subvariant.

Pfizer/BioNTech and Moderna also presented data for their mRNA vaccine candidates during the committee meeting, further validating the value of an XBB.1.5-directed monovalent vaccine.

Tristan Manalac is an independent science writer based in metro Manila, Philippines. He can be reached at or

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