“It’s a small number of people in each arm, and the study was not designed to demonstrate efficacy, which are standard warnings for a Phase 1 trial,” said Edward Belongia, epidemiologist and vaccine researcher at the Marshfield Clinic Research Institute in Wisconsin. “That said, it does look very promising – at least as promising if not more than the other vaccines we’ve reviewed.”
The data has been posted to a pre-print server, meaning it has yet to be peer reviewed.Novavax recruited around 130 healthy volunteers into its trial and gave them a placebo or one of four escalating doses of its vaccine. Everyone who has received the vaccine has developed neutralizing antibodies against SARS-CoV-2, which can help prevent infection.
The best responses came from volunteers who received two injections of the Novavax vaccine three weeks apart, plus an adjuvant to enhance its effects. After 35 days, these participants had neutralizing antibody levels that, on average, were about four times higher than those seen in a group of 32 patients who had recovered from the disease.
About 80% of these volunteers had side effects at the injection site, including pain and tenderness. Over 60% had other side effects, mainly headaches, muscle pain and fatigue. Most reactions were mild or moderate, but eight patients had side effects considered severe; Novavax said no hospitalization was necessary. All reactions resolved after a few days, and none were life threatening.
The study, conducted in Australia, recruited roughly equal numbers of men and women between the ages of 18 and 59. The volunteers were approximately 79% white, 15% Hispanic, 13% Asian, 6% native and 2% black. The median age was 31 years old.
It is not known whether the vaccine’s demonstrated effect on neutralizing antibodies will protect people from Covid-19. Scientists are still mapping the underlying mechanisms that boost immunity to SARS-CoV-2.
It is also impossible to directly compare Novavax’s product, NVX-CoV2373, with other vaccines in development, said Kathryn Edwards, scientific director of the Vanderbilt Vaccine Research Program in Nashville, Tennessee. Injections from Moderna, AstraZeneca, CanSino, and the partnership of Pfizer and BioNTech all elicited neutralizing antibodies in early trials, but each study used different methods to detect immune responses, meaning they cannot be judged by. face to face as long as there is no data on actual rates of SARS-CoV-2 infection.
Overall, the Novavax trial is “another encouraging study that looks like the vaccine could be a potential winner, but efficacy and safety studies need to be continued,” said Edwards.
Moderna, AstraZeneca, and Pfizer are all recruiting more than 30,000 volunteers each for placebo-controlled Phase 3 trials to determine whether their vaccines can prevent Covid-19. Novavax plans to start a similar study in the fall, with Johnson & Johnson, Sanofi and others.
Novavax’s vaccine is one of the few to be funded by Operation Warp Speed, a U.S. effort to develop treatments and vaccines for the novel coronavirus by the end of this year. The company is expected to receive $ 1.6 billion in federal funding, which will support its development efforts and pay for 100 million doses of NVX-CoV2373 if it is found to be safe and effective. The company also receives up to $ 388 million from the Coalition for Epidemic Preparedness Innovations, a nonprofit organization funded in part by the Bill and Melinda Gates Foundation.
NVX-CoV2373 is designed to mimic a key protein found on the surface of SARS-CoV-2, simulating a viral infection to force the body to produce antibodies against Covid-19. Novavax, which has no approved products, has spent nearly three decades and $ 1.5 billion trying to develop vaccines with its technology.
An earlier version of this story incorrectly stated that trial volunteers who had severe reactions were hospitalized.