Biotech company Novavax announced Thursday that its coronavirus vaccine proved to be 89% effective against COVID-19, according to the results of a late-stage study conducted in the United Kingdom.
This “next-generation” vaccine also shows immunity against the U.K. and South African variants of the virus, the firm said in a press release.
The NVX-CoV2373 vaccine demonstrated 89.3% efficacy in its phase 3 trial in the U.K., which enrolled over 15,000 participants, the company said.
The trial also found that “efficacy by strain was calculated to be 95.6% against the original COVID-19 strain and 85.6% against the UK variant strain.” The U.K. strain is about 40%-70% more transmissible, and preliminary data from the U.K. suggests it may also be more deadly.
In the second part of its phase 2 trial in South Africa, which enrolled more than 4,400 patients, Novavax said it found that its vaccine was 60% effective. This suggests that the vaccine is effective against the South African strain since, according to the press release, the strain “was widely circulating in South Africa” during the phase 2 trial. The South African variant appears to be more transmissible but not more lethal than the original strain.
Novavax also noted that being infected with the original strain of the virus may not offer protection against the South African strain. About one-third of the enrollees in the phase 2 trial had previous coronavirus infections, which Novavax says it believes to be caused by the original strain.
The “subsequent infections during the study were largely variant virus,” the company said in its press release. “These data suggest that prior infection with COVID-19 may not completely protect against subsequent infection by the South Africa escape variant, however, vaccination with NVX-CoV2373 provided significant protection.”
