A federal vaccine advisory committee will meet on Tuesday to decide whether adults in the United States will soon have a fourth COVID-19 vaccine option.

The vaccine was developed by Novavax, a Gaithersburg, Maryland-based company, at the same time as others in 2020, but the company struggled to produce large quantities of its shot.

Experts believe that because it is a more traditional vaccine than some of the others, it may persuade some vaccine skeptics to get the shots.

“There are a lot of reasons that aren’t scientifically based for not having taken the vaccine (yet),” said Vivian Riefberg, a professor at the University of Virginia’s Darden School of Business. “Because it’s traditional technology, it may persuade some people.”

The Moderna and Pfizer-BioNTech shots, which have been administered to three-quarters of the American population, use mRNA technology to teach the body to produce the spike protein found on the surface of the coronavirus that causes COVID-19. The immune system will attack the viral cells once it recognizes the spike protein.

The Novavax vaccine delivers the spike protein directly, mass-produced in insect cells rather than the body, and accompanied by an adjuvant that increases its effectiveness. Protein-based vaccines have been used to prevent diseases such as hepatitis B, pertussis, pneumonia, and meningococcal disease, among others.

It’s unclear how many people will opt for the two-dose Novavax shots after declining the other three.

Novavax is currently only requesting permission to administer its shots as a primary, two-dose vaccine to people who have not yet been immunized. Before their vaccine can be offered as a booster, the company must present more data to regulators.

The Novavax vaccine is already available in over 40 countries and is expected to be especially useful in low- and middle-income countries that may lack the freezer capacity needed for long-term storage of mRNA vaccines.

Travel writer Troy Petenbrink was such a fan of Novavax’s shot that he volunteered to take part in a vaccine trial in 2020.

But he became dissatisfied with the company after being left in limbo due to vaccine delays – not fully vaccinated, but unable to get answers from Novavax about what he should do.

The Washington, D.C., resident eventually dropped out of the trial and received the two-dose Moderna vaccine in addition to his two Novavax doses.

Nonetheless, Petenbrink believes Novavax’s vaccine will be as effective as the others.

Novavax was a small company with fewer than 100 employees, no products on the market, and a disappointing clinical trial when it was awarded $1.8 billion in federal funds to develop, test, and manufacture a COVID-19 vaccine. It quickly proved safe and effective in lab and animal studies, though those took longer to complete than the mRNA research.

Instead of focusing on perfecting the manufacturing process at their North Carolina production plant, “they were going after a geographic footprint of Europe, Asia, Latin America, and North America, to come up concurrently and start producing.”

He claimed that if the plan had worked, Novavax’s shots would have been the best in the world. However, the company’s plan “had hiccups,” according to Yadav, including difficulty attracting skilled workers to staff all of those facilities. Every country’s rollout was delayed.

Riefberg believes the vaccine could have been available sooner if the company had more experience with vaccine development or partnered with a more experienced company, as BioNTech did.

Bringing a vaccine to market entails more than just creating the shot. “We all tend to focus on the innovation in the creation of the new (vaccine) and not the innovation in the scaling, because it’s not as sexy – but it’s as important, sometimes more important,” she said.

The Novavax vaccine appears to be less effective in people over 65, providing only 79% protection against symptomatic disease, compared to 91% protection in younger adults. The study did not have many older participants who became ill, so those figures may not be accurate, according to the FDA review.

The FDA raised concerns about the shot’s cardiovascular effects in its analysis of Novavax data, which the Vaccines and Related Biological Products Advisory Committee will discuss in a daylong meeting Tuesday.