Novavax’s Covid-19 adult vaccine, two doses per day, cleared Tuesday as a crucial step toward FDA authorization.

After an extensive public meeting, in which safety and effectiveness data were weighed, the FDA’s independent committee of vaccine experts voted 21-0 to approve the authorization for the shot to be used in the United States. While the FDA follows most of its recommendations, but it’s not required to. Novavax could be cleared by the FDA for distribution in America as early as next week.

Before pharmacies or other health-care professionals can begin administering the shots, however, they would need to approve them by the Centers for Disease Control Prevention.

Novavax’s vaccine would mark the fourth approval of Covid in the U.S. Novavax’s shot is based upon protein technology used for decades to develop vaccines against HPV and hepatitis B. Moderna and Pfizer were among the first to use messenger RNA technology, so this technology is different.

Novavax’s vaccine could be appealing to patients who are not yet immunized. Dr. Peter Marks is the FDA officer responsible for reviewing vaccine effectiveness and safety. Though Johnson & Johnson’s shot is also available, the CDC has restricted its use due to a risk of blood clots primarily in women.

According to the CDC, 76% of Americans aged 18 or older have received at least two doses. This is primarily due to Moderna and Pfizer vaccines. Heather Scobie of the CDC’s Covid crisis response team, says that about 27 million U.S. adults haven’t received their first dose. Novavax executives think that the vaccine will be appealing to people who don’t want vaccination but prefer a technology option with a better track record than mRNA.

According to clinical trials from Mexico and the U.S., Novavax’s vaccine prevented Covid-related illness 90% of the time and 100% for severe illnesses. The trial took place from December 2020 to September 2021. This was months before highly contagious Omicron variants and their sublineages were dominant in the U.S.

FDA officials indicated that no information was available about the effectiveness of Novavax against omicron. However, they stated in briefing documents before Tuesday’s meeting that shots will likely protect against serious illness caused by the variant. Novavax is a Covid vaccine that was created to fight the original, 2019-infected strain. The virus has changed dramatically in the last two years. All vaccines that protect against Covid-related mild illnesses have seen their effectiveness drop significantly as the virus evolved.

“The study was done quite some time ago, and the cases that accrued weren’t during the time that the omicron circulated,” Dr. Lucia Lee from the FDA’s Division of Vaccine Research stated during her presentation before the committee.

Novavax’s Chief Medicine Officer Dr. Filip Dubovsky claimed that although two doses produced an immune response, it was still lower than for the Wuhan strain. Dubovsky stated that a third dose increased the immune response to omicron by levels similar to those of the Wuhan strain. Novavax will ask FDA for authorization to use a third dose in the United States if it clears the first series, Dubovsky said.

Dubosvky explained that while we don’t actually have data on efficacy against Omicron, the technology that we do have generates an immunity response against a wide range of variants. 

According to FDA briefing papers, the most frequent side effects from Novavax’s shot were headache, muscle pain, injection site pain and fatigue. FDA officials raised concerns that Novavax might have heart inflammation risks, as with Moderna and Pfizer’s shots.

A safety database of nearly 40,000 Novavax vaccine users found that four men between the ages of 16 and 28 had myocarditis or pericarditis within twenty days after receiving their shot. However, one man was suffering from a viral infection which could have contributed to the symptoms. Pericarditis refers to inflammation of the outer lining and heart muscle.

Lee explained that the Novavax shot was triggering these symptoms and it is concerning. mRNA vaccination and heart inflammation among younger men. The case of the mRNA shotsAccording to the CDC, myocarditis can be caused by Covid infections than from vaccination.

Novavax’s Chief Safety Officer Dr. Denny Kim stated that the myocarditis rates were almost the same for people who had received and those who didn’t receive the vaccine, but slightly higher in people who got the shot.

 “We believe that the totality of the clinical evidence here is not enough to establish an overall causal relationship with the vaccine,” Kim told the committee. Novavax will monitor for signs of inflammation of the heart in its patient base and actual-word injections where it is authorized.

Novavax’x vaccine technology is different from Moderna and Pfizer’s shots. Messenger RNA is used to convert human cells to factories, which then produce Covid’s spike protein. These copies are used to inducing an immune reaction that combats the virus. This is where the virus attaches itself to human cells and invades them.

Novavax makes copies of the virus spike that are not infected by humans. A baculovirus is used to infect moth cells. They then make copies of the virus spike, which are later purified and extracted. Injecting the spike copy into patients, which is not able to replicate and does not cause Covid, induces an immune reaction against it.

Adjuvant is also used in the vaccine to increase the immune response. It’s an extract taken from South America’s bark tree. Each shot contains 50 micrograms adjuvant and 5 micrograms spike copy.

Novavax can be stored in the refrigerator, but Moderna or Pfizer vaccines must remain at subzero temperatures.

This is an ongoing story. Keep checking back for more updates.