The American biotechnology company Novavax confirmed Thursday, March 11 that its vaccine was 89% effective against Covid-19, but that its effectiveness was significantly reduced against the South African variant, according to the final results of clinical trials .
In detail, its efficacy was 96.4% against the initial strain of the virus, and 86.3% against the British variant (B.1.1.7), according to the results communicated by the company, and 48.6 % only against the South African variant.
Read also: Covid-19: should you get the AstraZeneca vaccine injected?
These data augur the forthcoming filing of an urgent authorization request, particularly in the United Kingdom, where Novavax already announced last week that it wanted to formulate it at the start of the second quarter of 2021. At the end of January, Novavax had communicated similar interim results .
Phase 3 clinical trials were conducted in the UK on more than 15,000 people aged 18 to 84, 27% of whom were over 65.
Efficacy was 89.7% against symptomatic forms of the disease, with 96 cases of Covid-19 in the group given a placebo, compared to 10 cases in the vaccinated group.
The vaccine, named NVX-CoV2373, was also very effective against severe forms of the disease: five cases of Covid-19 were identified among the participants, but all were in the placebo group.
Another smaller trial (phase 2b) was also conducted on 2,665 participants in South Africa, where another variant (B.1.351) has become widely used.
There, the vaccine's efficacy fell to 48.6%.
Read also: AstraZeneca vaccine under surveillance
The Novavax vaccine is administered in two doses and uses a different technology from that used for vaccines already widely authorized in the world.
It is a so-called “subunit” vaccine, based on proteins that trigger an immune response, without viruses.
The company announced last week that it also wants to file an emergency authorization request in the United States in the second quarter of 2021, but it is not sure that the American health authorities will agree to study this request without waiting for the results of the parallel trials of the same vaccine in the United States.