London, Jan 19 : UK Health Secretary Matt Hancock said that there were more people currently in hospital than at any other time since the onset of the coronavirus pandemic early last year. Speaking at a virtual press conference at Downing Street, Hancock said on Monday that hospitals in the UK are under enormous pressure amid surging coronavirus infections with someone admitted every 30 seconds, reports Xinhua news agency. The number of people in hospital with the virus is at its highest level at 37,435, he said. Meanwhile, a study suggested that nearly a third of people who were discharged from hospitals in England after being treated for Covid-19 were readmitted within five months, and almost one in eight died, the Guardian newspaper reported on Monday. But on a positive note, Hancock said the government's plan to vaccinate all the four most vulnerable groups covering 15 million people by mid-February is on track. People aged 70 and over and those listed as clinically extremely vulnerable in England have begun to receive the first dose of coronavirus vaccine from Monday. Hancock confirmed that the UK is aiming to offer all adults the vaccine by September, noting that 4 million jabs having been delivered so far. Earlier in the day, Prime Minister Boris Johnson warned that the easing of lockdown will be "gradual" despite progress of vaccine rollout. "I'm afraid I've got to warn people it will be gradual, you can't just open up in a great open sesame, in a great bang, because I'm afraid the situation is still pretty precarious," Johnson said during a visit to the manufacturing facility for the Oxford/AstraZeneca vaccine. England is currently under the third national lockdown since the outbreak of the pandemic in the country. Similar restriction measures are also in place in Scotland, Wales and Northern Ireland. Another 37,535 people in the UK tested positive for Covid-19, the lowest daily increase since the start of the year, according to official figures released on Monday. The daily figure, down from 38,598 on Sunday, brought the total number of coronavirus cases in the country to 3,443,350, the data showed. Another 599 have died within 28 days of a positive test, which increased the country's overall death toll to 90,031. /IANS