Vaccines for people aged in their 40s in the UK will begin this month, reports have claimed.
Health officials are reportedly set to send the last batch of invites for jab bookings to over-60s.
Vaccination teams are predicted to be able to get through all people in the 50s age group in March and move on to the next group, according to the Telegraph.
More than 20 million people in Britain have now had at least a first dose of a coronavirus jab, the latest official figures showed on Sunday.
Around 5 million over-50s could be offered the jab as soon as next week, the newspaper reported.
It has based its predictions on the current rate of the rollout, which is moving on average at the speed of about 2.5 million jabs a week.
If vaccination teams keep up their current pace it could see people in their 40s offered vaccines by the end of March.
The Chancellor has earmarked £1.6billion left over in the government’s Covid fund for the vaccine programme after Boris Johnson laid out his roadmap out of lockdown.
Mr Sunak will set out the plans for the cash at Wednesday’s Budget.
It comes after officials confirmed a Brazilian variant had been discovered in the UK.
Up to six confirmed cases of the P.1 variant first seen in the city of Manaus have been found – and health officials have no idea where one of the carriers is.
An urgent alert was issued on Sunday night to find the missing person thought to be infected with the variant after a Covid test in England, processed on February 14 came back positive but without a name on it.
The person did not fill in their test registration card, officials said.
The strain is thought to spread more rapidly than other variants.