Washington – The US biotech company Novavax said on Thursday that its COVID-19 bipartisan vaccine showed an overall efficiency of 89.3% in a large phase 3 clinical trial in Great Britain and remained highly effective against a variant first identified there. But the positive news was somewhat offset by other results showing that it offered less protection against a highly transferable variant of the coronavirus first identified in South Africa.
Like the British strain, the variant first found in South Africa is now rapidly spreading around the world, and the first cases have been confirmed in the US. In recent weeks, there have been concerns that the vaccines being developed around the world could be less effective against the South African variety, in particular, and while the results of the Novavax trial seem to confirm some degree of resistance, both the company and an outside health practitioner are optimistic about the level of protection offered against both new strains.
“NVX-CoV2373 has the potential to play a significant role in solving this global public health crisis,” said the company’s president and CEO, Stanley Erck, using the name Novavax for the vaccine. “We look forward to continuing to work with our partners, staff, researchers and regulators around the world to make the vaccine available as soon as possible.”
UK Prime Minister Boris Johnson tweeted that the results were “good news,” adding that UK drug regulators would now review the vaccine for possible approval.
The vaccine was one of six candidates supported by a US government project formerly known as Operation Warp Speed that raised the Maryland-based company $ 1.75 billion. It is also being tested in a trial in the US and Mexico, which has recruited about 16,000 of the 30,000 participants to date.
Unlike the Pfizer, Moderna and AstraZeneca vaccines, which provide the genetic instructions that cause human cells to make a key protein of the virus, the Novavax injection injects the proteins directly into the body to generate an immune response. arouse.
“Pretty Good” vs. South African type
The UK study involved 15,000 people aged 18 to 84, including 27% who were older than 65. The first interim analysis was based on 62 cases of confirmed COVID-19 among participants, of which 56 cases were observed in the placebo group versus six cases among people who have received the vaccine.
The company’s preliminary analysis showed that the variant first identified in the UK, called B.1.1.7, was found in more than 50% of the confirmed cases. Novavax said the results showed their vaccine was 95.6% effective against the original COVID-19 strain and 85.6% against the UK variant.
But the level of protection was lower in a smaller mid-stage trial in South Africa. That study enrolled just over 4,400 patients from September to mid-January, during which time the B.1.351 variant, which contains critical mutations along the virus’s spike protein, spread rapidly across the country.
Overall efficacy was 49.4% in this study, but that figure increased to 60% among the 94% of the subjects who were HIV negative.
Worryingly, Novavax said that about a third of the study participants in South Africa had previously been infected with the original form of the virus, while subsequent infections during the study were largely of the variant.
The results come just days after South African researchers told CBS News the new species appeared in the country very resistant to antibodies in blood samples from people infected with the original strain of the virus, which were first discovered in Wuhan, China in late 2019. That research worried scientists that previous infection might provide little immunity to the new South African variant, and could potentially affect the vaccines’ efficacy.
However, Amesh Adalja, a physician and senior scholar at the Johns Hopkins Center for Health Security, told AFP that it was important to keep the reduced efficacy in perspective and that the vaccine was still a success.
“Sixty percent against the variant is still pretty good,” he said. “It’s clear that the Novavax vaccine has prevented serious illness, and that’s ultimately the most important thing.”
Professor Shabir Madhi, who is leading the South African trials, said Thursday night that the Novavax results were something “he never dreamed of” when he saw how bad the natural immunity of the first wave of COVID infections, with the original strain, was it opposed the variant in South Africa.
Erck, CEO of Novavax, called the preliminary results of the South African study “beyond people’s expectations”.
The UK and South Africa studies were the first to assess the performance of a COVID-19 vaccine against both the UK and South African variants in real world trials.
Moderna has previously said that the vaccine “must” remain effective against both new highly contagious variants, but the study cited in them was based on laboratory research and not real-world testing against human infection.
Pfizer also has reported laboratory results suggesting the vaccine will be effective against the British variant, but it has not yet revealed data for testing against the strain found in South Africa.