The Indian coronavirus strain is potentially 60 percent more infectious than the UK strain, a leading epidemiologist said on Friday.

Prof Neil Ferguson from Imperial College London said of the Indian strain, also known as the Delta variant, “the news is not as positive as I would like”.

“The best estimate at the moment is this variant may be 60 percent more transmissible than the Alpha variant,” Prof Ferguson told the BBC’s Radio 4 Today program.

“It partially escapes vaccine immunity, though there is still a good deal of protection, and may well cause severe disease from the hospitalization data reported.

“It could be anywhere from 30 to 100 percent more, but 60 percent is a good central estimate.”

Public Health England said on Thursday the strain was now the dominant Covid-19 variant in the UK, with 12,431 cases recorded up to June 2 – a sharp increase from the previous week’s 6,959 infections.

Health officials said there was solid evidence to suggest those infected with the variant were at greater risk of being admitted to hospital.

However, about two thirds of people with the Indian strain were unvaccinated against Covid-19.

Of the 479 people who attended hospital in England between February 1 and May 31, all of whom were confirmed as having the Indian variant, 309 were unvaccinated. Eighteen of those admitted had two doses of a Covid-19 vaccine.

From 137 cases admitted to hospital overnight, 90 were unvaccinated, while seven had two doses.