Coronavirus infections are falling fast across England, the latest large survey has found, with positive tests now less than one-third the level reported three weeks ago.

According to the React-1 study led by Imperial College London and published on Thursday, just 0.51 per cent of the randomly selected sample of 85,400 volunteers was infected between February 4 and 13, compared with 1.57 per cent between January 6 and 22.

“It’s very reassuring to see this speed of decline,” said Prof Steven Riley of Imperial College. “It is better than we had expected.”

However, the researchers found no evidence that vaccination was having an effect on infection. The decline in positive swab tests was no steeper in people over 65, who have received the vast majority of vaccinations so far, than in younger age groups.

Prof Paul Elliott, React-1 director, said: “These encouraging results show that lockdown measures are effectively bringing infections down. It’s reassuring that the reduction in numbers of infections occurred in all ages and in most regions across the country.”

The fall has been steepest in London, from 2.83 in the last survey to 0.54 per cent. North East England had the smallest decline, from 1.22 to 0.82 per cent, underlining concerns raised in other research of regional variations in the rate of decline across the country.

The React-1 results followed pleas by senior scientists on Wednesday for the government to be led by data rather than dates, ahead of Boris Johnson’s announcement on lifting coronavirus lockdown restrictions next week.

Prof Angela McLean, chief scientific adviser at the Ministry of Defence, told MPs on the science and technology committee that the vaccine rollout was a cause for optimism, but added that it was important to take a cautious approach to easing restrictions.

“Let’s use data not dates,” she said. “The important thing is to watch what is happening in the real world and do our best to make judgments properly in real time about whether we are going too fast or need to pause before taking the next step.”

The prime minister has said he will announce a “road map” for lifting restrictions on February 22, with schools expected to be the first to reopen from March 8.

Speaking during a visit to a vaccination centre in south Wales on Wednesday, Johnson stressed that the government would be adopting a “prudent” approach to removing coronavirus measures.

“We’ll be setting out what we can on Monday about the way ahead and it’ll be based firmly on a cautious and prudent approach to coming out of lockdown in such a way to be irreversible,” he said. “We want to be going one way from now on, based on the incredible vaccination rollout that you’re seeing in Cwmbran.”

Mark Woolhouse, professor at Edinburgh university and a member of the government’s Scientific Pandemic Influenza Group on Modelling, told MPs on the science committee that the vaccine rollout was “exceeding expectations”.

“The actual performance of the vaccine, the transmission blocking potential is key but so of course is its actual ability to protect against death and disease and keep people out of hospital . . . all those numbers are looking really good,” he said.

He also argued that the government may be in a position to lift restrictions earlier than planned, adding: “If you’re driven by data and not the dates, right now you should be looking at early unlocking because the data are so good.”

However, McLean warned that information relating to the impact of vaccines on transmission was still unclear. “The number one thing we don’t know about vaccines still is this issue of how infectious you are if you catch Covid even if you have been vaccinated,” she said.