More Than 2 Years Into the Pandemic, the FDA Considers Novavax
The FDA is expected to authorize Novavax, a new COVID-19 vaccine, though it's still under review.
Why it matters
Novavax will be the first protein-based vaccine for COVID-19 available in the US, though the technology has been around for decades. While this type of vaccine has some advantages in the pandemic, it also has unique challenges.
The FDA and CDC will need to decide how, or if, the US will use Novavax.
With the country's eyes on the pending availability of COVID-19 vaccines for children under 5, most people have either received (or chosen not to receive) the COVID-19 vaccines and booster doses available to them. (If you're 50 and up, you're eligible for two boosters or a total of four shots.)
But a committee of scientists and other experts that advise the US Food and Drug Administration last week endorsed Novavax, a protein-based COVID-19 vaccine, for authorization. If the FDA gives it the green light, it'll be the fourth COVID-19 vaccine on the market in the US, and the first to use a more traditional, protein-based vaccine technology against the coronavirus.
So, why now? More than two years into the pandemic, a majority of Americans (about 67%) are fully vaccinated against COVID-19, and many have added a booster dose or two. Those hesitant or opposed to vaccination seem to be continuing those stances, according to a poll from the Kaiser Family Foundation.
The percentage of American adults who answered the poll who said they would "definitely not" get a COVID-19 vaccine ranged from 15% in December 2020 to 17% April 2022. Novavax had a contract with the federal government through Operation Warp Speed, but has experienced manufacturing problems that have hindered a potential emergency use authorization. In addition to examining more data on how Novavax fares against the omicron variant, the FDA will need to sign off on the company's production before authorizing the vaccine.
However, some scientists are hopeful that Novavax may one day be used as a booster dose in combination with other vaccines, and that its primary series may fill a need for a more traditional and potentially equally effective COVID-19 vaccine. It's also already available in other countries, including Canada and Australia, under the name Nuvaxovid.
"It's good to have a vaccine on board like Novavax because it's another option for those that might have contraindications to the other vaccine platforms," Ross Kedl, a professor of immunology and microbiology at the University of Colorado Anschutz Medical Campus, said in an email. "Some have allergic reactions or more rare concerns like blood clots." The Johnson & Johnson COVID-19 vaccine is still authorized in the US, but use of it has been limited because of a rare but serious risk of blood clots.
This leaves Pfizer's and Moderna's vaccines as the two currently recommended options for most adults. Authorizing Novavax also opens the door for it to be used as a booster dose or part of a mix-and-match approach with other COVID-19 vaccines. Here's what to know.VioletaStoimenova/Getty Images
What is Novavax?
How is it different?
Novavax is a COVID-19 vaccine that uses a more traditional protein-based technology, unlike the other vaccines currently available in the US: Pfizer-BioNTech and Moderna use mRNA technology, and Johnson & Johnson is a viral-vector vaccine. In the Novavax vaccine, a purified protein of the virus is mixed with what's called an adjuvant -- additives that "wake up the immune response and tell it to take this target seriously," Kedl said. Dr.
Glenn Wortmann, an infectious disease specialist with MedStar Health, said the general approach of most vaccines is to use a protein base. "Specifically, Novavax is very similar to the hepatitis B vaccine that's given," which most of us receive as children, Wortmann said. Some vaccines for influenza, shingles and other ailments use a similar technology.
While it offers another option, however, the jury may be out on whether Novavax offers superior immunity to Pfizer's and Moderna's vaccines. "Immunologically speaking, in my view it does not really bring an awful lot on its own to the table that is not already well-addressed by the mRNA vaccines," Kedl said. However, it is easier to store and ship than mRNA vaccines, he said.
This may be an advantage when vaccinating harder-to-reach communities where keeping finicky vaccines cool in the fridge may be difficult. But Novavax has serious disadvantages when it comes to manufacturing, Kedl said, because it isn't cheap for the company to produce and purify the proteins. "mRNA vaccines skip that step because they turn each individual into their own vaccine manufacturer," he said. mRNA vaccines work by teaching our cells to make the protein themselves that will trigger an immune response.
For this reason, mRNA vaccines are easier to adjust than Novavax when a new variant comes along, Kedl said. "The mRNA platform is far more modifiable than what Novavax does," he said. "Every time a new variant vaccine needs to be made, Novavax is going to have to do a lot of work in the lab to figure out which changes will still allow a good protein to be made and purified at mass quantities."Yulia Reznikov/Getty Images
How effective is Novavax?
Published results from a trial found that Novavax was more than 90% effective against symptomatic COVID-19, and 100% effective against severe disease and death. But importantly, that trial was conducted before the omicron or delta variants were widely circulating.
Both the delta and omicron variants -- including omicron subvariants like BA.2, BA.2.12.1 and BA.4 -- are more contagious and evade some immunity from vaccines and prior infection. Real-world data comparing the effectiveness of Novavax to other vaccines doesn't exist yet. Per the World Health Organization, "It is impossible to compare vaccines head to head due to the different approaches taken in designing the respective studies."
When will Novavax be available?
The FDA still needs to authorize the primary series (the first set of shots, not the booster doses).
While it typically accepts its advisory committee's recommendation, the agency needs to review more data. Once it does, a committee of experts for the Centers for Disease Control and Prevention will vote whether to recommend Novavax, and for whom, and then the CDC's director will sign off the recommendation. The FDA's advisory committee is scheduled to meet for a public meeting on June 28 to discuss future COVID-19 vaccine formulas -- including for the likely fall or winter COVID-19 surge.
Once authorized and recommended, it's unclear how available, exactly, Novavax will be compared with Moderna's and Pfizer's vaccines, which are stocked at pharmacies, clinics and doctors' offices nationwide. The US government had originally planned to purchase 110 million doses of the vaccine, The New York Times reports, but the US has a sufficient supply of COVID-19 vaccines for primary doses and booster shots.
How will the US pay for Novavax?
While COVID-19 vaccines have been free and available to all Americans, recent funding stalled in Congress and federal officials have warned we're running out of money for COVID-19 tests, vaccines, treatments and related spending. Some services for Americans without health insurance have already expired.
However, it is likely COVID-19 vaccines will remain free, at least for a while. Money for COVID-19 testing and protective equipment is being moved around to cover the costs of vaccines and treatment for the fall, The New York Times reports.
Can Novavax be used as a booster?
The FDA is considering the authorization of Novavax as a primary series (the first two doses). If the FDA gives it the green light, it may very well become another option in the US booster catalog.
Last fall, the FDA signed off on the mix-and-match approach to the authorized COVID-19 boosters, or a heterologous booster dose. Once there's data on using a vaccine like Novavax with mRNA vaccines, "There may be people that received three or four of the mRNA vaccines and might be interested in trying a different vaccine as part of a mix-and-match strategy," Wortmann said. "I think that the real advantage of the Novavax vaccine is to the field more broadly," Kedl similarly said. "Because it now has one more vaccine platform to mix and match with the other vaccines."
The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice.
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