London, June 3 : UK Health Secretary Matt Hancock has confirmed that more than three-quarters of adults in the country have been administered their first Covid-19 vaccine dose. Till date, more than 39.5 million people have been given the first jab, according to the latest official figures. Speaking on Wednesday at the Global Vaccine Confidence Summit in Oxford, Hancock said the UK has started commercial negotiations with AstraZeneca for a vaccine targeted at variants of concerns, including the variant first detected in South Africa, known as Beta. Hancock said the global attention is increasingly turning to how to vaccinate the whole world, noting that more than half a billion doses of the Oxford-AstraZeneca vaccine have been released across the world, "mostly to low and middle income countries". Meanwhile, the UK government is facing increasing pressure to delay the final step of unlocking restrictions in England on June 21 due to concerns over the spread of the B.1.6172 variant, also known as Delta. "There isn't anything yet in the data to say we are off track but it is too early to make the decision about June 21," he said. Earlier Wednesday, Prime Minister Boris Johnson also said he has seen "nothing in the data" to suggest that the final step of easing Covid lockdown can't go ahead. However, he said there was a need to wait "a little bit longer" for a firm decision. From May 17, pubs, bars and restaurants in England were permitted to open indoors, while indoor entertainment resumed, including cinemas, museums and children's play areas. People were also allowed to travel abroad to a number of "green-list" countries without having to quarantine upon return as the ban on foreign travel has also been lifted. The government's roadmap is expected to see all legal limits on social contact to be removed on June 21. It is understood that a final decision on the planed easing of lockdown will not be made until June 14. /IANS