Novavax says its Covid-19 vaccine is 89 percent effective, but less so against South African variant
January 28, 2021
Novavax announced Thursday its Covid-19 vaccine is more than 89 percent effective at protecting against the virus based on preliminary data from a large late-stage trial in the United Kingdom.
But the vaccine was far less effective against a variant of the virus first discovered in South Africa, according to data from a small trial in that country, the company said.
The mixed results came on the same day that the United States announced it had found its first Covid-19 cases linked to the South African variant. The companies behind the two vaccines authorized for use in the U.S. — Moderna and Pfizer — have also said in recent days that their shots appear less effective against the South African virus strain.
Novavax, which is based in Maryland, has never brought a vaccine to market. The Trump administration awarded the company $1.6 billion to develop and test the vaccine, begin large-scale manufacturing and reserve 100 million doses.
Trial details: Novavax tested its vaccine in the U.K. during a period when a different variant of the virus — first detected in Britain and more transmissible than earlier versions — began circulating. The company's analysis of the 15,000-person Phase III trial found that the vaccine was 95.6 percent effective against the original Covid-19 strain and 85.6 percent effective against the U.K. variant, B.1.1.7.
Early data from a separate 4,400-person Phase IIb clinical trial in South Africa found that the vaccine was just 49.4 percent effective against the variant first discovered in that country. More than 92 percent of sequenced PCR samples taken from Covid patients in the South African trial were identified as that variant, which is known as B.1.351.
Novavax says it is developing booster shots of its vaccine to better protect against new strains of Covid and plans to start testing them in people in the second quarter of 2021.
Background: State health officials in South Carolina on Thursday announced the first known U.S. cases of the Covid variant first found in South Africa. The people infected with the variant had not traveled to South Africa, and there is no known connection between them, South Carolina officials said, which suggests that the variant is spreading in the community.
What’s next: Novavax is still enrolling participants in its U.S. clinical trial. The company has enrolled 16,000 people so far and expects to recruit its goal of 30,000 by early February.
Company executives told investors late Thursday they are in conversations with U.S. regulators to understand if the data from the U.K. and South African trials are adequate to apply for emergency authorization.
"We're still awaiting final decisions from the agency if that's an acceptable approach," one Novavax executive said.
The FDA has said that the efficacy threshold for an EUA is 50 percent, the same bar that set by the World Health Organization — but it has not clarified how that applies to recently emerged variants, such as those first spotted in the U.K., South Africa and Brazil. The agency has also told vaccine developers that they must test their vaccines in Phase III trials that enroll at lest 30,000 people.
Source: https://www.politico.com/
