After more than a year with two types of vaccines against covid-19 in use in the United States, the Food and Drug Administration, the FDA for its acronym in English, will consider the use of another new vaccine next week.
FDA vaccine advisers are meeting Tuesday to consider Novavax’s coronavirus vaccine for the country.
According to data included in an agency briefing document released Friday, an FDA review found the vaccine’s efficacy was 90.4% overall against mild, moderate, or severe COVID-19 over a two-year period. months and a half after completion of the two-dose primary series. The document notes that, in a primary analysis, the efficacy of the vaccine fell to 78.6% among adults aged 65 and older.
Those efficacy numbers were collected before the appearance of the omicron variant of the coronavirus. It is not clear how long the protection lasts or how well the vaccine will protect against omicron.
In an announcement published in December, the company reported that the vaccine had “wide cross-reactivity against omicron and other circulating variants from a 2-dose primary regimen, with responses increasing after a third dose at six months.”
Novavax’s vaccine, called NVX-CoV2373, is given in two doses three weeks apart for the primary vaccination series.
This is how the race for the covid-19 vaccine goesAdverse reactions to the Novavax vaccine
Although most adverse reactions to the vaccine were mild to moderate and lasted only a few days, the FDA described rare events of myocarditis and pericarditis (inflammation of the heart muscle and inflammation of the tissue surrounding the heart) associated with the vaccine.
“Multiple events of myocarditis/pericarditis have been reported in temporal relation to NVX-CoV2373 administration, similar to myocarditis following COVID-19 mRNA vaccines, raising concern for a causal relationship with NVX-CoV2373,” the FDA briefing document says.
The document describes six cases that occurred after vaccination with Novavax. Five were men between the ages of 16 and 67. Of the six cases, five were hospitalized but have since recovered.
An increased risk of myocarditis and pericarditis was identified among people who received the Pfizer/BioNTech and Moderna covid-19 mRNA vaccines now in use in the United States.
In a statement on Friday, Novavax specifically addressed concerns about heart inflammation: “We have learned that we can expect to see natural background events of myocarditis in any large enough database, and that young men are at higher risk. Myocarditis is most often caused by nonspecific viral infections.” The company said the rate of myocarditis in the vaccinated participants was similar to that in the placebo group: 0.007% and 0.005%, respectively.
The company added: “We believe there is insufficient evidence to establish a causal relationship. We will continue to monitor all adverse events, including myocarditis and pericarditis.”
Biden receives his second booster dose against covid-19The most common adverse reactions to the vaccine were pain at the injection site, fatigue, headache, and muscle pain. Reactions were reported more frequently in younger participants in clinical trials of the vaccine.
In its briefing document, the FDA summarized: “Known benefits among vaccine recipients 18 years of age and older relative to placebo are reduced risk of mild to severe COVID-19 at least 7 days after the second primary vaccination series.
At this Tuesday’s meeting, members of the FDA’s vaccine advisory committee will vote on the question “Based on the totality of available scientific evidence, do the risks of its use outweigh the benefits of the Novavax covid-19 vaccine when given as a 2-dose series in people 18 years of age and older?”
“We believe our vaccine offers a differentiated option,” says Novavax
In late January, Novavax announced that it had submitted an application to the FDA to authorize its coronavirus vaccine for emergency use in the United States.
In November, Indonesia became the first country to grant an emergency use authorization for the Novavax vaccine. It has since been licensed in the European Union, the United Kingdom, Canada, South Korea, Australia, India, the Philippines, and New Zealand, among other countries.
Although the majority of adults in the United States have been vaccinated against covid-19, the company’s director has said that he sees the Novavax vaccine as a potential option for booster doses, regardless of the type of vaccine that was administered for the initial doses of the vaccine.
Novavax’s vaccine was developed as a protein subunit vaccine, a more traditional type of technology than the mRNA used for Moderna and Pfizer vaccines. Other examples of subunit vaccines are the hepatitis B and pertussis vaccines.
“We believe that our vaccine offers a differentiated option based on a well-understood protein-based vaccine platform that can be an alternative to the portfolio of vaccines available to help combat the COVID-19 pandemic,” said Novavax CEO, Stanley Erck, in a statement in January.
Novavax’s protein-based coronavirus vaccine relies on something called recombinant nanoparticle technology and Novavax’s adjuvant, called Matrix-M, to stimulate an immune response and high levels of neutralizing antibodies.
Protein-based vaccines, like the one from Novavax, cause the body’s immune system to recognize small modified pieces of the virus they are targeting. In Novavax’s case, that means pieces of the spike protein from the coronavirus.
When the genetic sequence of the virus that causes covid-19 was published, scientists around the world quickly identified it as a coronavirus due to “spike proteins” on its surface. These spikes form large bumps, giving coronaviruses the appearance of wearing crowns, and “corona” is a word of Latin origin.
Novavax scientists identified the gene for the spike protein and created a modified version of that gene. The researchers cloned the genes into a baculovirus that infects insects. They then infected the cells of the moth, specifically, the cells of the armyworm, leading them to produce the spike protein of the coronavirus.
These virus-like nanoparticles were collected to make Novavax’s vaccine.
“The whole idea of the vaccine is to show the immune system something that looks, tastes and acts like a virus, except it doesn’t make you sick. So we made the spike protein. We put it on a particle basically, like a soap bubble, and it’s the size of the virus,” Dr. Gregory Glenn, president of research and development at Novavax, told Citizen Free Press last year.
“It’s not infectious. We never touch the coronavirus itself,” Glenn added. “Then that’s given to people, and they generate an immune response that’s very focused on just the spike, and I would say the hallmark of our vaccine is that it provides a very strong immune response with very few side effects, and the dose is very small and the vaccine can be stored at normal refrigeration temperatures.
Fauci: Current vaccination regimen gives strong protectionNovavax Begins Phase 3 Testing of Specific Booster for Omicron Variant
As Novavax seeks emergency use authorization for its NVX-CoV2373 vaccine, it is also studying a separate vaccine that specifically targets the omicron variant, called NVX-CoV2515. The company announced this week that it has begun a Phase 3 trial of this vaccine, evaluating its safety and efficacy as a booster shot.
“The trial will also seek to determine antibody responses to a bivalent vaccine, containing NVX-CoV2373 and NVX-CoV2515, administered in participants who received a booster series of an mRNA vaccine,” Novavax said in a statement.
The trial will test the omicron-specific vaccine and a bivalent vaccine in more than 1,000 participants in Australia.
Two doses of either the omicron-specific vaccine or the original NVX-CoV2373 vaccine will be administered after three doses of Pfizer-BioNTech and/or Moderna vaccines received at least three months before participants joined the trial.
Similarly, two doses of either the omicron-specific vaccine or the original NVX-CoV2373 will be administered after two doses of either mRNA vaccine received at least six months prior to joining the trial.
Two doses of the bivalent vaccine will be given to participants vaccinated with three doses of either mRNA vaccine at least three months before joining the trial.
The trial will last about 10 months and initial results are expected in the second half of this year.