An experimental Covid-19 vaccine appears to offer strong protection in late-stage UK and South Africa studies, said manufacturer Novavax.
The protein-based vaccine candidate, called NVX-CoV2373, was shown to be 89.3% effective at preventing coronavirus in participants in its Phase 3 clinical trial in the UK, according to the company.
The trial involved more than 15,000 people between 18-84, of which 27% were older than 65, Novavax said.
"NVX-CoV2373 is the first vaccine to demonstrate not only high clinical efficacy against Covid-19 but also significant clinical efficacy against both the rapidly emerging UK and South Africa variants," said Stanley Erck, the biotechnology firm's president and chief executive.
The trial was carried out in conjunction with the UK government's vaccine taskforce, with its chairman Clive Dix saying in a statement: "These are spectacular results, and we are very pleased to have helped Novavax with the development of this vaccine.
"The efficacy shown against the emerging variants is also extremely encouraging. This is an incredible achievement."
On 11 January, Reuters reported that the EU was "close to" signing a contract with Novavax for up to 200 million doses of its Covid-19 vaccine candidate. An EU official said a deal was "imminent".
While the jabs from Pfizer/BioNTech and Moderna need to be kept at ultra-low temperatures, the Novavax jab is stable for up to three months in a normal fridge.
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Novavax COVID-19 Vaccine Demonstrates 89.3% Efficacy in UK Phase 3 Trial https://t.co/8HCAbqIVxH pic.twitter.com/PFaLXkNmA8
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However, the positive news was offset by results that showed it was much less effective against a highly transmissible variant of the coronavirus first identified in South Africa.
A small trial in South Africa enrolled just over 4,400 participants from September to mid-January, during which time the B.1.351 variant, which contains critical mutations along the virus' spike protein, was spreading rapidly through the country.
Overall efficacy was 49.4% in this trial, but the figure rose to 60% among the 94% of trial participants who were HIV-negative.
Novavax said it began working on new vaccines against emerging strains in early January and expects to select ideal candidates in the coming days, then begin clinical testing in the second quarter of the year.
Unlike the Pfizer and Moderna vaccines, which use mRNA technology, the Novavax shot injects pieces of the coronavirus into humans in order to evoke an immune response.
Additional reporting AFP
