What to Know About Novavax, the 'Other' COVID Vaccine

We're on the cusp of the fall season, which means respiratory viruses like flu, RSV and COVID are expected to keep spreading as weather cools and more people gather indoors. 

Luckily, we've got vaccines in stock to help prevent respiratory viruses from turning into severe illnesses. In addition to flu vaccines for the general public and RSV vaccines for older adults and pregnant people, new COVID vaccines from Pfizer-BioNTech, Moderna and Novavax are available this season to reduce the risk of hospitalization. 

This means adults have a choice in which COVID vaccine they receive: an mRNA vaccine by Moderna or Pfizer, or Novavax, a protein-based vaccine that targets the virus in a more "traditional" way. All three have been authorized by the US Food and Drug Administration. While Moderna and Pfizer have been widely used over the last few years, the Novavax vaccine is building up a bit of a following. 

Novavax, a protein-based vaccine, is an option for those who don't want or can't take an mRNA vaccine. Novavax may also be appealing to those wanting to experiment with the "mix-and-match" approach to COVID boosters as a way to potentially strengthen the immune response. 

"Even though mRNA vaccines dominate the market for COVID vaccines, it remains important to have multiple different types of technologies against various pathogens because each may have specific use cases," Dr. Amesh Adalja, an infectious disease expert and senior scholar with Johns Hopkins Center for Health Security, said in an email. 

Here's everything we know about Novavax this year.

How is Novavax different from Pfizer and Moderna? 

Novavax is a protein-based vaccine, which people have associated with a "traditional" approach to vaccination. This is compared with mRNA technology, which does not use dead or weakened virus as an ingredient in the vaccine but instead uses genetic code to instruct the recipient's immune system to respond. 

However, Adalja said that calling Novavax traditional may be a "misnomer" because of it brings its own innovation it brings to the table. Novavax uses an insect virus that has been genetically engineered to express spike proteins, Adalja explained, which are then incorporated into the vaccine.

"The vaccine itself is coupled with an immune system booster, called an adjuvant, which increases its immunity," he said, referencing a component existing vaccines have also incorporated. 

This year, there are also slight differences between Novavax and Pfizer and Moderna's updated vaccines. Both mRNA vaccines have been tweaked to target the KP.2 strain of COVID-19, which is a slightly more recent version of the virus than what Novavax targets, which is KP.2's "parent" JN.1. While the FDA ultimately decided KP.2 was preferred in vaccines, all of them are expected to help protect against severe disease and death. 

Who should get Novavax? Does Novavax have different side effects? 

Novavax was authorized by the FDA for use in adults and children 12 and older, so younger kids can't get this vaccine. But for most adults, which COVID vaccine you should choose depends on your preference and what your neighborhood pharmacy has in stock. 

People may opt for Novavax for different reasons, though. For people who do not want to take an mRNA vaccine, having a protein-based vaccine like Novavax available means they can still be vaccinated for the fall and winter season. 

Other people may be interested in Novavax for its use in the "mix-and-match" approach to boosting, which in the past has been associated with a strong immune response. 

There is some early research that suggests Novavax may have fewer short-term side effects, such as muscle fatigue and nausea, but "we can't say this for sure," Joshua Murdock, a pharmacist and pharmacy editor of GoodRx, said in an email. 

"This isn't proven, and side effects do vary by person," Murdock said. He added the CDC doesn't recommend one vaccine over the other, even in people who are immunocompromised.

In general, mRNA vaccines have been found to be fairly "reactogenic" compared to other vaccines, Adalja said, noting that it also depends on the individual. But if someone had a bad experience with the mRNA vaccine, Adalja said, they "may fare better with the Novavax vaccine."

Some flu-like side effects can be expected post-vaccine, no matter which one you choose. This includes symptoms like headache, tiredness, a sore arm and even chills. Not experiencing symptoms doesn't mean your immune system isn't kicking in, but experiencing some side effects may signal that your immune system is responding to the jolt, so to speak. 

In rare cases, myocarditis or heart inflammation problems have been associated with COVID vaccination, particularly in younger men and adolescents within the two weeks following vaccination. Research so far shows that Novavax, like mRNA vaccines, may also carry this rare side effect though. 

Following high levels of COVID this summer in the US, more information will be needed to see how all vaccines and their freshly targeted formulas fare against the virus that's expected to continue to spread this fall and winter. 

"There's no strong evidence that one vaccine is preferable to another in specific individuals, but that will be an important avenue to study for more precision-guided vaccine recommendations," Adalja said. 

How to find a Novavax vaccine 

Novavax announced on Sept. 13 that doses of its vaccine will be available at the following pharmacies: 

Novavax also has a vaccine finder on its website. To use it, type in your ZIP code in the small search box, and pharmacies nearby with the vaccine in stock will be displayed.