The Food and Drug Administration on Wednesday cleared Novavax’s coronavirus vaccine for emergency use in adults, endorsing a fourth shot for preventing COVID-19 as infections in the U.S. remain at high levels.
The FDA’s authorization comes more than a year after the Maryland-based drugmaker reported initial data on its shot’s effectiveness and one month after a group of independent advisers to the agency backed its use.
Novavax’s vaccine “provides another alternative for adults and adds another vaccine to the COVID-19 vaccine supply for the United States,” Peter Marks, director of the FDA office that reviews vaccines, said in a statement. The U.S. recently bought 3.2 million doses of the shot.
Novavax’s vaccine is the first authorized in the U.S. that relies on an older protein-based technology, which health officials believe could help draw some people who are hesitant of the mRNA approach used by Moderna as well as Pfizer and BioNTech.
However, the shot is only cleared for adults who have never received a COVID-19 vaccine before. Nearly 77% of U.S. adults over 18 years old have already received two vaccine doses, leaving a small fraction of people eligible to receive Novavax’s shot.
Moderna and Pfizer, meanwhile, have moved on to developing booster shots to combat waning immunity in fully vaccinated individuals — something for which Novavax’s shot can’t be used.
Moderna and Pfizer are each advancing newer shots containing components that target omicron. But those vaccines may have to be updated again, as the FDA recently asked developers to tailor their next boosters to newer versions of the variant that are widely circulating.
Novavax, too, is developing an omicron-targeting booster, though its shot is further behind. The company expects to have clinical data in September. The government has been hoping to start a new booster campaign in the fall.
For Novavax, though, the FDA’s clearance is nonetheless a breakthrough as it’s the first U.S. authorization for the 35-year-old company, which has accumulated more than $3 billion in losses over that time period.
The company received its first regulatory authorization in Indonesia last November, and to push its vaccine forward was awarded $1.4 billion in funding over two years from the U.S. government and the international non-profit group CEPI. But Novavax has faced manufacturing and quality-related delays that led it to miss its target of a vaccine rollout by mid-2021.
Novavax’s authorization was based on results from a large Phase 3 study that showed its vaccine reduced COVID-19 cases by 90% compared to a placebo. However, that effectiveness was against the virus strains circulating in 2021, before the omicron subvariants now circulating became dominant.
Some experts have questioned Novavax’s vaccine on that basis, although the company’s chief medical officer, speaking to an FDA expert committee in June, pointed to laboratory tests indicating a strong immune response to omicron.
The FDA’s prescribing information for Novavax’s vaccine includes a warning of the risk of a type of heart inflammation called myocarditis, although that side effect only occurred in a few participants in the company’s trials. Myocarditis has also been associated in rare cases with both Moderna’s and Pfizer’s vaccines, and was a focus of discussion at the advisory committee meeting for Novavax’s shot at the June meeting.