Is Novavax, the latecomer COVID vaccine, worth the wait?

By Amy Maxmen, KFF Health News

Erin Kissane, a co-founder of the COVID Tracking Project, rolled up her sleeve for the Novavax COVID-19 vaccine in mid-October soon after it was finally recommended in the United States. Like many people with autoimmune diseases, she wants to protect herself from a potentially devastating COVID infection.

Kissane’s autoimmune arthritis seems to make her susceptible to unusual vaccine side effects. After getting an mRNA booster last year, her joints ached so painfully that her doctor prescribed steroids to dampen the inflammation. She still considers the mRNA vaccines “miraculous,” knowing COVID could be far worse than temporary aches.

Nonetheless, when the pain subsided, she pored through studies on Novavax’s shot, a vaccine that is based on proteins rather than mRNA and has been used since early 2022 in other countries. Data from the United Kingdom found that people more frequently reported temporary reactions — like low fevers, fatigue, and pain — as their immune system ramped up in the days following booster vaccination with Moderna’s mRNA vaccine versus the one by Pfizer. And those boosted with Novavax’s had fewer complaints than either of those. That finding was corroborated in an analysis of international data published last year.

Such studies have driven people with long COVID and chronic fatigue syndrome (also known as myalgic encephalomyelitis, or ME/CFS) to seek out Novavax, too, since the FDA and the Centers for Disease Control and Prevention greenlighted Novavax’s vaccine — updated to protect against recent omicron coronavirus variants — about three weeks after recommending updated mRNA vaccines in September.

Waiting paid off for Kissane, whose arm was briefly sore. “It was a dramatically different experience for me,” she said. “I hope that plays out for others.”

Another group who waited on Novavax are biologists who geek out over its technology. When asked why he opted for Novavax, Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai, replied on X, formerly known as Twitter: “Because I am [a] vaccine nerd, I like insect cell produced vaccines.”

Whereas mRNA vaccines direct the body to produce spike proteins from the coronavirus SARS-CoV-2, which then train a person’s immune system to recognize and fight the virus, Novavax simply injects the proteins. These proteins are grown within moth cells in a laboratory, while other protein-based shots use cells from mammals. And Novavax has said that a special ingredient derived from the bark of Chilean soapbark trees enhances the vaccine’s power.

Research suggests that the Novavax vaccine is about as safe and effective as the mRNA shots. Its main disadvantage is arriving late to the scene. Vaccine uptake has plummeted since the first shots became widely available in 2021. Nearly 70% of people got the primary vaccines, compared with fewer than 20% opting for the mRNA COVID boosters released last year. Numbers have dwindled further: As of Oct. 17, only 5% of people in the United States had gotten the latest COVID vaccines, according to the Department of Health and Human Services.

Daniel Park, an epidemiologist at George Washington University, said low rates might improve if people who felt lousy after their last mRNA shots gave Novavax a try. It protects against severe illness, but researchers struggle to specify just how effective this and other vaccines are, at this point, because studies have gotten tricky to conduct: New coronavirus variants continuously emerge, and people have fluctuating levels of immunity from previous vaccines and infections.

Still, a recent study in Italy suggests that Novavax is comparable to mRNA vaccines. It remained more than 50% effective at preventing symptomatic COVID four months after vaccination. Some data suggests that mixing and matching different types of vaccines confers stronger protection — although other studies have found no benefit.

Given all this, Park held out for the Novavax vaccine on account of its potentially milder side effects. “Between a demanding full-time job and two young kids at home, I wanted to stay operational,” he said. His arm was sore, but he didn’t have the 24-hour malaise accompanying his last mRNA shot.