CNN

FDA advisers to weigh risks and benefits of Novavax’s Covid-19 vaccine

Jun 6, 2022, 11:00 PM
Dr. Nita Patel, Director of Antibody discovery and Vaccine development, lifts a vial with a potenti...
Dr. Nita Patel, Director of Antibody discovery and Vaccine development, lifts a vial with a potential coronavirus, Covid-19, vaccine at Novavax labs in Gaithersburg, Maryland on March 20, 2020, one of the labs developing a vaccine for the coronavirus, Covid-19. Photo credit: Andrew Caballero-Reynolds/AFP/Getty Images

(CNN) — After more than a year with two types of Covid-19 vaccines in use in the United States, another will be up for consideration by the US Food and Drug Administration next week.

The FDA’s vaccine advisers are set to meet Tuesday to consider Novavax’s coronavirus vaccine for the nation.

Based on data included in an agency briefing document posted Friday, an FDA review found that the vaccine’s efficacy was 90.4% overall against mild, moderate or severe Covid-19 for a period of 2½ months after completing the two-dose primary series. The document notes that, in a primary analysis, the vaccine efficacy fell to 78.6% among adults 65 and older.

Those efficacy numbers were collected before the emergence of the Omicron coronavirus variant. It remains unclear how long protection lasts or how well the vaccine will protect against Omicron.

In an announcement published in December, the company reported that the vaccine had “broad cross-reactivity against Omicron and other circulating variants from a primary 2-dose regimen, with responses that increased following a third dose at six months.”

Novavax’s vaccine, called NVX-CoV2373, is given as two doses three weeks apart for the primary vaccination series.

Although most adverse reactions to the vaccine were mild to moderate and lasted just a few days, the FDA did describe rare events of myocarditis and pericarditis — inflammation of the heart muscle and inflammation of tissue surrounding the heart — associated with the vaccine.

“Multiple events of myocarditis/ pericarditis were reported in temporal relationship to NVX-CoV2373 administration, similar to myocarditis following mRNA COVID-19 vaccines and raising concern for a causal relationship to NVX-CoV2373,” the FDA’s briefing document says.

The document describes six cases that happened after vaccination with Novavax. Five were among males ranging in age from 16 to 67. Of the six cases, five were hospitalized but have since recovered.

An increased risk of myocarditis and pericarditis has been identified among people who received the mRNA Pfizer/BioNTech and Moderna Covid-19 vaccines now used in the United States.

In a statement Friday, Novavax addressed the heart inflammation concerns specifically: “We have learned that we can expect to see natural background events of myocarditis in any sufficiently large database, and that young males are at higher risk. Myocarditis is most often caused by nonspecific viral infections.” It said that the rate of myocarditis in vaccinated participants was similar to 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.”

The most common adverse reactions to the vaccine were pain at the injection site, fatigue, headache and muscle ache. Reactions were reported more commonly in younger participants in the vaccine’s clinical trials.

In its briefing document, the FDA summarized, “The known benefits among vaccine recipients 18 years of age and older relative to placebo are reduction in the risk of mild to severe COVID-19 occurring at least 7 days after the second primary series vaccination.”

In Tuesday’s meeting, the FDA’s vaccine advisory committee members will vote on the question “Based on the totality of scientific evidence available, do the benefits of the Novavax COVID-19 Vaccine when administered as a 2-dose series outweigh its risks for use in individuals 18 years of age and older?”

‘We believe our vaccine offers a differentiated option’

In late January, Novavax announced that it had submitted a request for the FDA to authorize its coronavirus vaccine for emergency use in the United States.

In November, Indonesia became the first country to grant emergency use authorization of Novavax’s vaccine. It has since been authorized in the European Union, the United Kingdom, Canada, South Korea, Australia, India, the Philippines and New Zealand, among other countries.

Even though most adults in the United States have been vaccinated against Covid-19, the head of the company has said that it sees Novavax’s vaccine as a potential option for booster doses, regardless of which type of vaccine was given for a person’s initial doses.

Novavax’s vaccine was developed as a protein subunit vaccine, a more traditional type of technology than the mRNA used for the Moderna and Pfizer vaccines. Other examples of subunit vaccines are the hepatitis B and pertussis vaccines.

“We believe our vaccine offers a differentiated option built on a well-understood protein-based vaccine platform that can be an alternative to the portfolio of available vaccines to help fight the Covid-19 pandemic,” Novavax CEO Stanley Erck said 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 Novavax’s work by getting the body’s immune system to recognize little modified pieces of the virus it’s targeting. In Novavax’s case, that means pieces of the coronavirus spike protein.

When the genetic sequence for the virus that causes Covid-19 was published, scientists around the world quickly identified it as a coronavirus because of the “spike proteins” on its surface. These spikes form large protrusions, giving coronaviruses the appearance of wearing crowns, and “corona” is the Latin word for “crown.”

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 moth cells — specifically, cells from the fall armyworm — prompting them to produce the coronavirus spike protein.

These virus-like nanoparticles were harvested 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, with the exception that it doesn’t make you sick. So we made the spike protein. We put it in a particle — basically, like a soap bubble — and it’s the size of the virus,” Dr. Gregory Glenn, president of research and development for Novavax, told CNN last year.

“It’s not infectious. We never touch the coronavirus itself,” Glenn added. “Then that is given to people, and they make an immune response that’s very much focused just on the spike — and I would say, the hallmark of our vaccine is, it gives a very strong immune response with very few side effects, and the dose is very small and the vaccine can be stored with normal refrigerated temperatures.”

Novavax starts Phase 3 trial of Omicron-specific booster

As Novavax seeks emergency use authorization of its NVX-CoV2373 vaccine, it also is studying a separate vaccine that specifically targets the Omicron variant, called NVX-CoV2515. The company announced this week that it has started a Phase 3 trial of this vaccine, assessing its safety and efficacy as a booster shot.

“The trial will also seek to determine the antibody responses to a bivalent vaccine, containing both NVX-CoV2373 and NVX-CoV2515, administered in participants who have received a booster series of an mRNA vaccine,” Novavax said in a news release.

The trial will analyze 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 given after three doses of either the Pfizer-BioNTech and/or Moderna vaccines that were received at least three months before participants joined the trial.

Similarly, two doses of the Omicron-specific vaccine or the original NVX-CoV2373 will be given after two doses of either mRNA vaccines received at least six months before joining the trial.

Two doses of the bivalent vaccine will be administered in 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.

Today’s Top Stories

CNN

Shoppers wait in line outside a retail warehouse as people rush to prepare for Tropical Storm Ian, ...
Holly Yan and Nouran Salahieh, CNN

Hurricane Ian could be ‘something that we haven’t seen in our lifetime,’ Tampa forecaster says

While Ian is forecast to become a "major hurricane" based on wind speeds, storm surges can be even deadlier than the winds, said Michael Brennan, acting deputy director of the National Oceanic and Atmospheric Administration.
23 hours ago
In this photo provided by Wreckhouse Press a home fights against high winds caused by post Tropical...
Nouran Salahieh, CNN

Hundreds of thousands without power in Atlantic Canada after Fiona rumbles north

Poor weather conditions have hampered power restoration efforts, Nova Scotia Power President and CEO Peter Gregg said Saturday. More than 900 power technicians were on their way to the area, but some customers may experience power outages for several days, he said.
23 hours ago
Tropical Storm Ian...
Haley Brink, Dakin Andone and Nouran Salahieh, CNN

Florida officials urge residents to prepare for Tropical Storm Ian, forecast to be a major hurricane before it reaches Cuba

Floridians are bracing for Tropical Storm Ian, which is expected to rapidly intensify and become a hurricane on Monday before hitting western Cuba.
2 days ago
First Lady Utah vaccine mandate...
Priscilla Alvarez, CNN

Biden touts climate package at Global Citizen Festival

President Joe Biden and first lady Jill Biden addressed the Global Citizen Festival early Sunday, underscoring the administration's commitment to climate action
2 days ago
(Photo courtesy of Salt_Verse on Twitter)...
Rachel Metz, CNN Business

This guy is using AI to make movies — and you can help decide what happens next

"Salt" resembles many science-fiction films from the '70s and early '80s. The way it was created points to what could be a new frontier for making movies.
2 days ago
The short range missile was fired early Sunday morning local time from the Taechon area of North Py...
Yoonjung Seo, Junko Ogura and Larry Register, CNN

North Korea fires ballistic missile into waters off east coast of Korean peninsula

North Korea has fired a ballistic missile into the waters off the east coast of the Korean peninsula, according to officials in both South Korea and Japan.
3 days ago

Sponsored Articles

a worker with a drill in an orange helmet installs a door in the house...
Price's Guaranteed Doors

Home improvement tip: Increase the value of your home by weatherproofing doors

Make sure your home is comfortable before the winter! Seasonal maintenance keeps your home up to date. Read our tips on weatherproofing doors.
Curb Appeal...
Price's Guaranteed Doors

How to have the best of both worlds for your house | Home security and curb appeal

Protect your home and improve its curb appeal with the latest security solutions like beautiful garage doors and increased security systems.
A paper reading IRS, internal revenue service is pictured...
Jordan Wilcox

The best strategies for dealing with IRS tax harassment | You have options!

Learn how to deal with IRS tax harassment. This guide will teach you how to stop IRS phone calls and letters, and how to handle an IRS audit.
spend a day at Bear Lake...
Bear Lake Convention and Visitors Bureau

You’ll love spending the day at Bear Lake | How to spend a day at Bear Lake

Bear Lake is a place that needs to be experienced. Spend a day at Bear Lake.
Prescription opioids can be disposed of during National Prescription Take Back Day...
Know Your Script

Prescription opioid misuse | How to protect your family from the opioid epidemic

Studies have shown that prescription opioid misuse has increased since COVID-19. So what do you need to know about these opioids?
national heart month...
Intermountain Healthcare

National Heart Month: 5 Lifestyle Changes to Make Today to Keep You Heart Healthy

Heart disease is the leading cause of death for both men and women. One person dies every 36 seconds in the United States from cardiovascular disease
FDA advisers to weigh risks and benefits of Novavax’s Covid-19 vaccine