Novavax Stumbles Again After COVID-19 Vaccine Hit with EMA Warning - UPDATED

Novavax_STR/NurPhoto via Getty Images

STR/NurPhoto via Getty Images

The saga continues for Novavax. Just a day after the vaccine was given emergency use authorization (EUA) by the U.S. Food and Drug Administration, the European Medicines Agency (EMA) said it is placing a severe allergic reaction warning on the product. Following the announcement, shares of the company plummeted over 27 percent in early afternoon trading. 

The U.S. product label will also include warnings against giving the shot to individuals with a history of allergic reactions to any of the components in the vaccine. The product is authorized as a two-dose primary series for adults 18 years and older. 

The EMA’s label will also include warnings about unusual or decreased feeling in the skin as a potential new side effect. About 250,000 doses of the Novavax vaccine, named Nuvaxovid, have been injected in Europe since December 2021.

The Saga of the Novavax COVID-19 Vaccine

On June 7, the FDA’s Vaccines and Related Biological Products Advisory Committee voted 21-0, with one abstention, to recommend authorization of the vaccine. FDA briefing papers released prior to the advisory committee meeting expressed concern over four cases of myocarditis, or heart inflammation, that were seen in pivotal clinical trials. This is the same issue reported with other vaccines, especially the AstraZeneca-Oxford product, although it has also been observed with the Pfizer-BioNTech and Moderna vaccines. All of the incidences are very rare.

Omicron Efficacy Unknown

The EUA submission was based on results from a Phase III clinical study of about 30,000 participants between December 2020 and September 2021. Overall efficacy observed was 90.4% overall and 78.6% in people 65 years and older. The trial was run before the rise of the Delta and Omicron variants, but the briefing documents noted that “based on the efficacy estimate in the clinical trial of this vaccine, it is more likely than not that the vaccine will provide some meaningful level of protection against COVID-19 due to Omicron, in particular against more severe disease.”

Most recently, the Omicron BA.5 variant, which is even more likely to evade immunity from vaccines and previous infection than earlier variants, has dominated. The data in the submission does not address BA.5.

During the advisory committee meeting, Dr. Filip Dubovsky, M.D., Novavax’s chief medical officer, pointed out that results from its adolescent trial demonstrated that two shots of the vaccine induced an immune response against Omicron. However, like with other vaccines, it was lower than against the wildtype Wuhan strain. A third shot boosted it against Omicron to comparable levels to the first two shots against the wild-type strain.

“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.

Bivalent Vaccine Against Omicron in the Works

A Phase III trial of the vaccine against the Omicron strain is ongoing. That study is of a bivalent vaccine that contains both NVX-CoV2373, the vaccine authorized today and in use in other countries, and NVX-CoV2515, which targets Omicron. Results are expected in the second half of this year. Other vaccine manufacturers are testing bivalent vaccines targeting Omicron as well.

The Novavax vaccines use a traditional type of vaccine manufacturing process. Copies of the virus’s spike protein are grown in insect cells, purified and inserted into nanoparticles with an immune-stimulating adjuvant. The mRNA vaccines used by Pfizer-BioNTech and Moderna also leverage nanoparticles to transport the vaccines’ payloads, but package mRNA that codes for the spike proteins. Protein vaccines are used in other indications, such as hepatitis B and shingles. This type of vaccine also requires less stringent temperatures than the mRNA vaccines for storage and transportation.

A Long Road to US Approval 

The company has battled manufacturing problems, which delayed production globally. The company indicates that those problems have been resolved and that it has distributed more than 40 million doses as of March 2022 in Asia, Europe and other countries. The Serum Institute of India manufactured the vaccine for Novavax. Novavax is based in Gaithersburg, Maryland.

With about two-thirds of the U.S. population already vaccinated, the market for the Novavax vaccine would seem to be limited, although it does pave the way for its entry as a booster shot, particularly if the bivalent vaccine is effective in the latest study. Part of the rationale is that because the vaccine leverages a more traditional technology, people who are reluctant to get the mRNA vaccines because they’re worried about the newer tech might now be willing to be inoculated.  

Novavax will still need to conduct a final round of quality testing for the vaccine over the next few days, according to Politico. But the Biden administration had already acquired 3.2 million doses of the shot ahead of the authorization. The Trump administration pre-ordered 110 million doses, investing $1.6 billion in the process back in 2020, but the company’s production issues and problems meeting U.S. regulatory standards repeatedly delayed the process.

Now that the FDA has granted EUA, a decision by the U.S. Centers for Disease Control and Prevention is up next.

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