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 two billion doses per year, including from the Serum Institute of India

Novavax said its coronavirus vaccine was 89.3 per cent effective in preventing COVID-19 in a trial conducted in the UK, and was nearly as effective in protecting against the more highly contagious variant first discovered in the UK, according to a preliminary analysis.

A mid-stage trial of the vaccine in South Africa, where a troubling new variant of the virus is common, showed 60 per cent effectiveness among people who did not have HIV.

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 two billion doses per year, including from the Serum Institute of India.

The company said that this was interim data and it will be two to three months before it is ready to apply for authorisation with regulators.

The UK trial, which enrolled 15,000 people aged 18 to 84, is expected to be used to apply for use in Britain, the European Union and other countries.

Executives said the company was discussing with the US Food and Drug Administration whether the UK and South Africa data was enough to apply for US emergency use authorization.

The UK study took place as the more highly transmissible UK variant was circulating. The preliminary analysis suggests the vaccine was 85.6 per cent effective against this mutation, the US company announced in its news release. It did not provide detailed data.

In the UK trial, the effectiveness of the vaccine was close to that of the two authorised vaccines from Pfizer with BioNTech and Moderna, whose two-dose regimens were both around 95 per cent effective at preventing COVID-19 in clinical trials.

South African trial of Novavax vaccine seen to be 60 per cent effective, says head of trial.

John Moore, a professor of microbiology and immunology at Weill Cornell Medical College in New York, said the Novavax UK data are essentially the same as results from 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 US,” he said.

Dr Amesh Adalja, an infectious disease expert at the Johns Hopkins Center for Health Security, said the results were in line with hopes, and that he was concerned people would focus too much on the weaker effectiveness shown in South Africa.

“We’ve gotten spoiled because we’ve seen the Moderna and Pfizer numbers. I know people are going to be alarmed, but 60 per cent efficacy against the new variant is acceptable,” he said, noting that the FDA initially said it would approve a vaccine that was at least 50 per cent effective.

The South African variant has been shown to evade antibody protection in lab studies by Moderna and Pfizer/BioNTech.

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.

A 30,000-person trial in the US and Mexico that began in December also is underway. The company has received $1.6 billion from the US government in funding for the vaccine trial and for 100 million doses.

It also has received at least $388 million in backing from the Coalition for Epidemic Preparedness Innovation (CEPI), a Norway-based group backed by 14 governments, the Bill and Melinda Gates Foundation, and Britain’s Wellcome Trust.

Novavax’s is a 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.