Novavax’s two-dose Covid-19 vaccine for adults 18 years of age and older was a key step towards approval by the Food and Drug Administration on Tuesday.
The FDA’s Committee of Independent Reviewers on Vaccines voted 21 to 0, with one abstention, to recommend US approval of the vaccine after an all-day meeting in which they weighed the safety and efficacy data. The FDA generally follows the committee’s recommendations, although it is not required to do so. The agency may allow the Novavax vaccine for distribution in the US as early as this week.
The Centers for Disease Control and Prevention still needs to approve shots before pharmacies and other healthcare providers can start giving them to people.
The Novavax vaccine will be the fourth Covid vaccine approved for use in the US. Maryland Biotech’s vaccines are based on a protein technology that has been used in hepatitis B and HPV vaccines for decades. This technology is different from the Pfizer and Moderna vaccines, which were the first to receive FDA approval using messenger RNA technology.
Dr. Peter Marks, who heads the FDA’s office responsible for reviewing the safety and efficacy of vaccines, said the Novavax vaccine could potentially appeal to people who have not yet been immunized because they would rather get a shot that is not based on Pfizer’s mRNA technology. . and Modern. While the Johnson & Johnson injection is also available, the CDC has restricted its use due to the risk of blood clots, primarily in women.
About 76% of adults aged 18 and over have already received two doses in the US, mostly Pfizer and Moderna vaccines, according to the CDC. However, about 27 million adults in the US have yet to receive their first dose, according to Heather Scobie, a member of the CDC’s Covid Emergency Response Team. Novavax executives believe their vaccine will appeal to some people in this group who are not opposed to vaccination but want a variant that uses technology with a longer track record than mRNA.
According to the results of clinical trials conducted by the company in the US and Mexico, the Novavax vaccine was 90% effective in preventing Covid disease across the board and 100% effective in preventing severe disease. However, the trial was conducted from December 2020 to September 2021, months before the highly contagious omicron variant and its various sub-series became dominant in the US.
In briefing papers released ahead of Tuesday’s meeting, FDA officials said there was no data on the effectiveness of Novavax’s omicron vaccine, though vaccines likely still protect against severe disease from that variant. Novavax, like any Covid vaccine, was developed to fight the original strain of the virus that first emerged in Wuhan, China in 2019. However, over the past two years, the virus has mutated greatly. The effectiveness of all vaccines against mild forms of Covid has declined significantly as the virus has evolved.
“The study was done quite a while ago, and it said that the number of cases that were reported were not at the time that omicron was circulating,” Dr. Lucia Li, an FDA Vaccine Research Officer, said during her presentation to the committee.
Novavax chief medical officer Dr. Philip Dubowski said data from the company’s study in teenagers showed two doses elicited an immune response against omicron, although it was lower than against the Wuhan strain. The third dose boosted the immune response against omicrons to a level comparable to the first two doses against the Wuhan strain, Dubovsky said. Novavax plans to ask the FDA for approval for a third dose if the agency clears the primary batch for use in the US, he said.
“It’s a fact that we don’t have efficacy data against omicrons, we have a technology that we think induces a broad immune response that has been shown against a wide range of variants,” Dubowski said.
According to FDA reference documents, the most common side effects of Novavax injections were pain at the injection site, fatigue, headache, and muscle pain. 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 vaccines.
In a safety database of 40,000 Novavax vaccine recipients, four young adults aged 16 to 28 reported myocarditis or pericarditis within 20 days of vaccination, although one of them had a viral illness that could have caused symptoms. Myocarditis is an inflammation of the heart muscle, while pericarditis is an inflammation of the outer lining of the heart.
Lee said the cases are worrying because patients have reported their symptoms within days of receiving the Novavax shot, and a link has already been established between mRNA vaccination and heart inflammation in young men. In the case of mRNA vaccinations, the CDC found that the risk of myocarditis from Covid infection is higher than from vaccination.
Novavax’s chief safety officer, Dr. Denny Kim, said the incidence of myocarditis was almost the same in people who received and did not receive the vaccine in the clinical trial, although it was slightly higher among people who received the vaccines.
“We believe that the totality of clinical data here is not enough to establish an overall causal relationship with the vaccine,” Kim told the committee. He said Novavax is tracking cases of heart inflammation by gathering data from its clinical trials and the actual use of vaccines where they are already legal.
Novava’x vaccine technology differs in many ways from Pfizer and Moderna vaccines. The latter rely on messenger RNA to turn human cells into factories that make copies of the Covid spike protein to elicit an immune response that fights the virus. The spike is the part of the virus that attaches to and invades human cells.
Novavax produces copies of the virus spike outside the human body. The genetic code for the spike is placed into a baculovirus, which infects moth cells, which then produce copies of the spike, which are then purified and extracted. A spike copy that cannot reproduce or cause Covid is injected into humans, triggering an immune response against the virus.
The vaccine also uses another ingredient called an adjuvant, which is an extract purified from the bark of a tree in South America, to induce a broader immune response against the virus. Injections consist of 5 µg spike copy and 50 µg adjuvant.
The Novavax vaccine can also be stored at refrigerator temperature, while the Pfizer and Moderna vaccines require deep sub-zero cold.
This is an evolving story. Please stay tuned for updates.