London, May 15 (IANS): UK Prime Minister Boris Johnson has announced that the country is planning to accelerate its coronavirus vaccination program for priority groups amid concerns over the spread of the Indian variant.

Speaking at a press conference at Downing Street on Friday, Johnson said those aged over 50 and those considered clinically vulnerable will be able to get a second vaccine dose after eight weeks, reports Xinhua news agency.

He said the spread of the new variant, known as B1617.2, would not affect the scheduled easing of lockdown in England from May 17.

But the Prime Minister said the variant could cause "serious disruption" to the next stage of lockdown easing on June 21.

Johnson said "at this stage" there are some important unknowns but he believes the variant is "more transmissible" than previous ones, and therefore the race between the vaccination programme and the virus could get tighter.

He said there was "no evidence" to suggest the current vaccines would be less effective against the strain.

Joining Johnson for the press briefing, England's Chief Medical Officer Chris Whitty said the country is going "in a very steady but rapid progression in terms of vaccination", starting with the most vulnerable people, including some people in their 30s.

Whitty said he hopes everybody in Britain has their first vaccine by end of July.

"That is the aim," he said.

The latest development came after four people in Britain have died due to the variant first detected in India,

Public Health England (PHE) said cases of the variant known as B1617.2 in Britain have more than doubled to 1,313, up from 520 infections recorded by PHE last week.

According to the latest official figures, more than 36.1 million people in Britain have been given the first jab of the coronavirus vaccine.