The Novavax vaccine is a traditional technology protein-based vaccine used against influenza and shingles. Many experts are eager to add another vaccine to the toolbox, especially since the Johnson & Johnson injection is now only recommended for people who cannot or will not get messenger RNA vaccines.
“It is important to have vaccine platform options in a pandemic that is constantly evolving,” said Gregory Poland, director of the Mayo Clinic Vaccine Research Group and paid consultant to Novavax.
But Novavax’s two-dose regimen is likely to have limited impact as it comes more than a year after other highly effective vaccines become available. Most of the vaccine-eligible population – people aged 18 and over – are already vaccinated. About 27 million adults in the United States have not received any vaccines, according to data from the Centers for Disease Control and Prevention.
Experts on the committee noted that the data supporting the vaccine’s authorization was old, showing its performance relative to a previous iteration of the virus, before current variants emerged.
Bruce Gellin, head of global public health strategy at the Rockefeller Foundation, abstained from voting but said he was giving the vaccine a “conditional yes”. He said the vaccine was shown to be generally safe and effective when clinical trials were carried out, but that “we don’t know if that’s true today.” He said it was important to monitor the vaccine’s performance as it comes into use.
Given that other safe and effective vaccines are available, the panel debated whether it was necessary to authorize another option. Some committee members expressed skepticism about whether people hesitant about vaccines would adopt the new vaccine.
But an FDA official stressed the importance of having options.
“Having a protein-based alternative may be more comfortable for some in terms of vaccine acceptance,” said Peter Marks, director of the FDA’s Center for Biological Assessment and Research. “I will use this as a moment in the pulpit to say: we have a problem with vaccine adoption that is very serious in the US, and anything we can do to make people more comfortable accepting these potentially lifesaving products is something that is obliged to do”.
The first vaccines to be authorized in the United States — from Pfizer and its German partner BioNTech and Moderna — were based on messenger RNA technology, which instructs the body’s cells to build proteins that teach the immune system to stop the coronavirus. The technology had been in development for years, but the pandemic was the first time it was authorized — and injections are now widely used.
People who can’t or won’t get mRNA vaccines can adopt Novavax vaccines, but the vaccine’s end use is likely as a booster. From now on, the company intends to seek authorization for the injection as a booster and for use in adolescents and children.
The Novavax vaccine was shown to be 90% effective in a clinical trial conducted before the emergence of the omicron variant of the coronavirus. The results were announced a year ago, but the vaccine has been repeatedly delayed by manufacturing challenges.
“It’s disappointing… that we don’t have more up-to-date information, because we’re looking at effectiveness against strains that no longer exist,” said Eric J. Rubin, member of the advisory committee, infectious disease specialist at Brigham and Women’s Hospital in Boston. Even so, he said the vaccine case was “pretty compelling,” considering that some people who have avoided mRNA vaccines have shown interest in Novavax.
Manufacturing regulatory issues are among the reasons for the delay in authorizing the shot by Novavax, which submitted its emergency authorization application in January. Doubts arose as to why it took so much longer for the shot to reach the US market. The Novavax vaccine is already authorized in dozens of countries, including Japan and Great Britain.
Marks of the FDA said the agency does not follow the example of other countries, including in manufacturing.
“We take manufacturing very seriously,” Marks said, adding that the FDA has “a very high standard,” which is why it is sometimes called the gold standard.
The FDA analysis identified five cases of heart inflammation occurring shortly after vaccination among 40,000 people in the company’s trials, raising concern that the injection may have the same rare risk as mRNA vaccines. Novavax executives disputed the FDA’s concern, noting that an analysis by the company showed that rates of cardiac myocarditis and pericarditis were extremely low and about the same in the group that received the vaccine and the study participants that received the placebo.
“I think the story is incompletely written here and we need to better understand what is going on,” said Filip Dubovsky, medical director at Novavax.
The Novavax coronavirus vaccine was one of six candidates supported by Operation Warp Speed, the federal program established to accelerate vaccine development. The government invested $1.6 billion in the Maryland company to support the development of the photos. Even with the influx of money, the challenges to scale were enormous.
“The messenger RNA vaccines are really remarkable. They are a great gift to humanity and were the first to cross the finish line. But whether or not they will be the ideal vaccine for these viruses is unclear,” said H. Cody Meissner, a specialist in pediatric infectious diseases at Tufts University School of Medicine. “I don’t think we want to rest on what we have right now, because there’s always an opportunity to improve a vaccine.”