Novavax: Here’s What We Know About the 4th COVID Vaccine

Adults who haven’t been vaccinated against COVID-19 yet (about 10% of people age 18 and up haven’t had any dose of COVID-19 vaccine) will be able to get Novavax, the fourth COVID-19 vaccine to be available in the US.

The US Centers for Disease Control and Prevention recommended Novavax as a primary series vaccine Tuesday, following an endorsement from a group of scientific advisers that gives guidance to the CDC. This was the final barrier for Novavax, and the vaccine will be available at pharmacies throughout the US in the coming weeks. 

Because it’s authorized only as a primary series and not a booster shot, the new vaccine can’t be used as a booster yet in people who’ve already been vaccinated. And though Novavax’s initial impact may be limited because of this, its availability will give those who’ve been holding out for a protein-based or more “traditional” vaccine another option. Vaccine types like Novavax have been around for more than 30 years, according to the CDC, and used against shingles, the flu and more. 

More than two years into the pandemic, the number of people who are fully vaccinated hasn’t changed very much in recent weeks, and those hesitant about vaccination seem to be firm in their stance, 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% in April 2022.

Besides Novavax, there are three other authorized or recommended COVID-19 vaccines on the market in the US, and two of them are still widely recommended for adults. (The Johnson & Johnson COVID-19 vaccine is still authorized in the US, but its use has been limited because of a rare but serious risk of blood clots. This leaves Pfizer’s and Moderna’s vaccines as the other two currently recommended options for adults.)

“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.”

Novavax has been a long time coming. The company had a contract with the federal government through Operation Warp Speed but has experienced manufacturing problems that have hindered a speedy emergency use authorization. Its COVID vaccine is already available in other countries, including Canada and Australia, under the name Nuvaxovid.

Here’s everything we know.

When can I get a Novavax shot? 

The Novavax rollout is a little different than earlier booster or vaccine rollouts, which made shots available to people almost immediately after the final sign-off by CDC Director Dr. Rochelle Walensky. (In Novavax’s case, there was no “preordering” of vaccine doses.) 

Based on the CDC’s planning document for Novavax, we can expect to see doses of Novavax out at US pharmacies as early as the end of July or the first week in August, Kristen Nichols, pharmacist and senior content management consultant at Wolters Kluwer, said in an email. But the timeline could also depend on where you live. 

“We can’t make an exact determination on when doses will be available, particularly in more rural areas where shipment may take longer to reach all care centers,” Nichols said.

To check when and where Novavax is available near you, you can use the COVID-19 vaccine finder to select your preferred vaccine type. 

Who can get Novavax? 

Novavax’s COVID-19 vaccine is for adults who haven’t received any COVID-19 vaccine yet. It’s authorized as a two-dose primary series for adults age 18 and up, with each dose typically given three weeks apart. 

Because it’s authorized as a primary series, people who’ve already been vaccinated can’t get it as an additional shot or booster right now. But as the FDA has authorized a mix-and-match approach with other COVID-19 vaccines in the past, Novavax’s authorization may be extended to more people in the future. 

As is the case with any other drug or vaccine, people with allergies to an ingredient in Novavax shouldn’t take it, says Nichols.

While Novavax’s primary series is the only one authorized now, it’s possible that Novavax could have a new, omicron-specific booster ready this fall or winter. After the FDA announced its plans for the fall vaccine rollout, Novavax said it’s speeding up work on an omicron-specific vaccine that targets the super-contagious BA.5. But like the other new, future vaccine, the FDA will need to authorize this separately. 

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 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.”

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 subvariant BA.5 — 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.” 

What are the side effects of Novavax? 

Like with other vaccines, side effects after getting the Novavax vaccine are typically mild, common and happen within seven days of getting the shot, according to the CDC. Examples are tiredness, fever, chills and a headache, which clear up within a couple of days. These are signs your immune system is reacting and mounting a defense.

Myocarditis and pericarditis (inflammation of the heart) is a rare side effect. Six out of roughly 40,000 vaccine recipients developed it in a clinical trial with Novavax, compared with one in the placebo group.

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.