CHICAGO (REUTERS) - Novavax Inc said on Thursday (Jan 28) its coronavirus vaccine was 89.3 per cent effective in preventing Covid-19 in a trial conducted in the United Kingdom, and was nearly as effective in protecting against the more infectious variant first discovered in the UK, according to a preliminary analysis.
A mid-stage trial of the vaccine in South Africa, where a potent variant of the virus is common, showed 60 per cent effectiveness among people who did not have HIV.
Novavax shares surged 34 per cent in after hours trading following release of the trial results on the same day the United States reported its first cases of the South African variant.
Novavax is already stockpiling vaccine at six operating manufacturing locations, and said it expects a total of eight plants in seven countries to produce at the rate of 2 billion doses per year, including from the Serum Institute of India.
The company on a conference call noted that this was interim data and executives said they expect it will be two to three months before they are ready to apply for authorization with regulators.
Novavax said the UK trial, which enrolled 15,000 people aged 18 to 84, is expected to be used to apply for regulatory review in Britain, the European Union and other countries. Some 27 per cent of people in the trial are over age 65.
The study took place as the more infectious UK variant was circulating, and the preliminary analysis suggests the vaccine was 85.6 per cent effective against this mutation, the US company announced in a news release. It did not provide the study data.
In the UK trial, the effectiveness of the vaccine was close to that of the two authorised vaccines from Pfizer Inc/BioNTech SE and Moderna Inc, whose two-dose regimens were around 95 per cent effective at preventing Covid-19 in clinical trials.
John Moore, a professor of microbiology and immunology at Weill Cornell Medical College in New York, said the UK data are essentially the same as those shown by Pfizer and Moderna.
"It's not statistically different. The vaccine basically works well in the predominant strain circulating in the UK, which means it's likely to be equally effective in the United States," he said.
"The South African variant is clearly going to be an issue, but it's not an absolutely catastrophic event either. The key thing is to stop this variant from spreading," Moore added.
The South African variant has been shown to evade antibody protection in lab studies by Moderna Inc and Pfizer Inc and BioNTech.
"The 60 per cent reduced risk against Covid-19 illness in vaccinated individuals in South Africans underscores the value of this vaccine to prevent illness from the highly worrisome variant currently circulating in South Africa, and which is spreading globally," Professor Shabir Maddi, lead investigator of the Novavax vaccine trial in South Africa.
Novavax said it started making new versions of its vaccine to protect against emerging virus variants in early January and expects to select ideal candidates for a booster in the coming days. The company said it plans to initiate clinical testing of these new vaccines in the second quarter of this year.
Novavax is also running a 30,000-person trial in the United States and Mexico that began in December after at least two delays it said were due to manufacturing scaling issues that prevented clearance by the FDA.
The company has received US$1.6 billion (S$2.1 billion) from the US government in funding for the vaccine trial and for 100 million doses.
It also has received at least US$388 million in backing from the Coalition for Epidemic Preparedness Innovation (CEPI), an Oslo, Norway-based group backed by 14 governments, the Bill and Melinda Gates Foundation, and Britain's Wellcome Trust.
Novavax has said it could produce up to 2 billion doses globally in 2021, once its manufacturing capacity is brought online.
Authorised vaccines so far have been based on newer technology platforms, such as the messenger RNA technology used by Moderna and Pfizer/BioNTech, or inactivated cold virus platforms used by Oxford University/AstraZeneca and CanSino Biologics.
Novavax's vaccine is a more conventional protein-based vaccine, an approach similar to that used by Sanofi to make its Flublok seasonal flu vaccine. The Novavax vaccine works with the company's proprietary Matrix-M adjuvant used to boost its efficacy.
