Matt Hancock will lead a Downing Street press conference on Monday afternoon.
The Health Secretary will deliver a coronavirus update from the No10 lectern today alongside Deputy Chief Medical Officer Jonathan Van Tam and NHS England's Dr Nikki Kanani, amid concern over the impact of new variants on the vaccine rollout.
Ministers have sought to reassure the public of the efficacy of the Oxford/AstraZeneca jab after South Africa put its rollout of the vaccine on hold over fears about its effectiveness against a new strain.
A study of around 2,000 people found the jab only offers minimal protection against mild disease of the South Africa variant.
Researchers were unable to conclude whether it worked against severe disease as the participants in the study were mostly young.
Health Minister Edward Argar said there was "no evidence that this vaccine is not effective in preventing hospitalisation, severe illness and death".
He pointed to comments from Professor Sarah Gilbert, who designed the Oxford Covid vaccine, where she said "there wasn't anything she could point to that caused her to be concerned that it would not be effective against severe forms of the illness, hospitalisation and death from the virus".
There are around 147 cases of the South African variant in the UK, Mr Argar said, but he admitted the data was a few days old.
He said booster jabs were already being developed to tackle variants, which could be deployed each year similar to flu vaccines.
More than 12million people have now received their first dose of the vaccine, with almost 1,000 jabs per hour given at one point this weekend.
It puts the Government on course to meet its target to give 15million vulnerable people their first dose by February 15.
