Novavax’s two-dose Covid-19 vaccine for adults 18 years and older opened an important step on the road to Food and Drug Administration authorization on Tuesday.
The FDA’s committee of independent vaccine experts voted 21 to 0 with an abstention to recommend authorizing the vaccine for use in the US after a day-long public meeting in which safety and efficacy data were weighed. The FDA generally follows the committee’s recommendations, although it is not obligated to do so. The agency may clear the Novavax vaccine for distribution in the US later this week.
The Centers for Prevention and Disease Control would still need to approve the injections before pharmacies and other healthcare professionals can start giving them to people.
Novavax’s vaccine would be the fourth Covid vaccine authorized for use in the US The technology differs from injections by Pfizer and Moderna, which were the first to use messenger RNA technology to receive FDA approval.
Dr. Peter Marks, who leads the FDA office responsible for reviewing the vaccine’s safety and efficacy, said the Novavax vaccine would be potentially attractive to people who have not yet been immunized because they prefer to receive an injection that is not based on the mRNA technology used by the company. Pfizer and Modern. While the Johnson & Johnson injection is also available, the CDC has restricted its use due to the risk of blood clots particularly in women.
About 76% of adults age 18 and older have received two doses in the US, mostly with the Pfizer and Moderna vaccines, according to CDC data. However, about 27 million adults in the US have yet to receive their first dose, according to Heather Scobie, an employee with the CDC’s Covid emergency response team. Novavax executives believe their vaccine will appeal to some of that group who are not against vaccination but want an option that uses technology with a longer history than mRNA.
Novavax’s vaccine was 90% effective in preventing overall Covid disease and 100% effective in preventing serious illness, according to the results of the company’s clinical trials in the US and Mexico. However, testing was conducted from December 2020 to September 2021, months before the highly contagious omicron variant and its various substrains became dominant in the US.
In briefing papers published ahead of Tuesday’s meeting, FDA officials said there is no data available on the effectiveness of the Novavax micron vaccine, although the injections are likely to still protect against serious disease from the variant. Novavax, like all Covid vaccines, is designed to target the original strain of the virus that first emerged in Wuhan, China, in 2019. However, the virus has mutated dramatically over the past two years. The effectiveness of all mild Covid disease vaccines has declined substantially as the virus has evolved.
“The study was conducted for some time and said that the cumulative cases did not occur during the period when the omicron was circulating,” said Dr. Lucia Lee, an official with the FDA’s vaccine research division, during her presentation to the committee.
Committee member, Dr. Eric Rubin, an infectious disease specialist at Harvard, said he was disappointed that data on Novavax’s effectiveness against omicron had not been presented. However, Rubin said the data the company submitted meets the same standard used to authorize Pfizer and Moderna vaccines in December 2020.
Novavax medical director Dr. Filip Dubovsky told the panel that data from the company’s trials showed that two doses induced an immune response against the omicron, although it was lower than against the Wuhan strain. A third dose boosted the immune response against omicron to levels comparable to the first two doses, which were 90% effective against the disease, Dubovsky said.. Novavax plans to ask the FDA to authorize a third dose if the agency clears the primary series for use in the US, he said.
“It’s a fact 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 wide range of variants,” Dubosvky said.
The most common side effects of Novavax injections were pain at the injection site, fatigue, headache, and muscle aches, according to FDA briefing documents. However, FDA officials have also raised a red flag that the Novavax vaccine may be associated with a risk of heart inflammation, as is the case with the Pfizer and Moderna injections.
In a safety database of 40,000 Novavax vaccine recipients, four young people ages 16 to 28 reported myocarditis or pericarditis within 20 days of receiving the vaccine, even though one of them had a viral illness that could have caused the symptoms. Myocarditis is inflammation of the heart muscle and pericarditis is inflammation of the outer lining of the ear.
Lee said these cases are concerning because patients reported their symptoms within days of receiving a Novavax injection, and there is already an established link between mRNA vaccination and cardiac inflammation among younger men. In the case of mRNA injections, the CDC found that the risk of myocarditis is higher in Covid infection than in vaccination.
Novavax’s chief security officer, Dr. Denny Kim said the rates of myocarditis were essentially the same among people who received the vaccine and those who did not in the clinical trial, although they were slightly higher among people who received the injections.
“We believe that the totality of clinical evidence here is not sufficient to establish an overall causal relationship with the vaccine,” Kim told the committee. He said Novavax is monitoring cases of cardiac inflammation on the accumulated data from its clinical trials and real-word use of the injections where they are already authorized.
Panel member, Dr. Arthur Reingold, an epidemiologist at UC Berkeley, said he was skeptical that large numbers of people hesitant about vaccines would receive the Novavax vaccine, as there is evidence that the company’s vaccine may be associated with a risk of cardiac inflammation at comparable levels. those of Pfizer and Moderna. shots.
Cody Meissner, a pediatrician at Tufts University who is also on the committee, said there is clearly a link between Covid vaccines and myocarditis, although there is not enough data to say whether a company’s vaccine poses a greater risk.
Novavax’s vaccine technology differs in several ways from Pfizer’s and Moderna’s injections. The latter rely on messenger RNA to turn human cells into factories that produce copies of the Covid spike protein to induce an immune response that fights the virus. The spike is the part of the virus that latches onto and invades human cells.
Novavax makes copies of the virus’s spike protein outside the human body. The genetic code for the spike is put into a baculovirus that infects the moth’s cells, which then produce copies of the spike which are then purified and extracted. The spike copy, which cannot replicate or cause Covid, is injected into people inducing an immune response against the virus.
The vaccine also uses another ingredient called an adjuvant, which is a purified extract from the bark of a South American tree, to induce a broader immune response against the virus. The injections consist of 5 micrograms of the spike copy and 50 micrograms of the adjuvant.
Novavax’s vaccine can also be stored at refrigerator temperatures, while Pfizer’s and Moderna’s injections require sub-zero cold.
This is a developing story. Please check back for updates.