The Covid-19 vaccine developed by Pfizer and BioNTech is likely to protect against a more infectious variant of the virus, which was discovered in Britain and has spread around the world, according to results of further lab tests released today.

The encouraging results, based on an analysis of blood of participants in trials, are based on more extensive analysis than those released by the US drugmaker last week. Last week, Pfizer said a similar laboratory study showed the vaccine was effective against one key mutation, called N501Y, found in both of the highly transmissible new variants spreading in Britain and South Africa.

The latest study, which has not yet been peer reviewed, was conducted on 10 mutations, which are characteristic of the variant known as B117 identified in Britain.