A coronavirus vaccine is unlikely to be available before the year is out despite tens of millions of pounds being poured into UK trials that start imminently.

Health Secretary Matt Hancock confirmed £41 million of additional investment this week for vaccine research taking place at Oxford University and Imperial College London, with Oxford given the green light to start human trials on Thursday.

But Professor Chris Whitty, England’s chief medical officer, poured cold water on hopes that an impending vaccine could be the way out of the UK Covid-19 lockdown.

He told reporters at the daily Downing Street press briefing that some social distancing measures would need to stay in place until there was a vaccine or drug which reduced the severity of Covid-19.

“Until we have those, and the probability of having those any time in the next calendar year are incredibly small and I think we should be realistic about that, we’re going to have to rely on other social measures, which of course are very socially disruptive as everyone is finding at the moment,” he said.

Also on Wednesday, the co-ordinator of Covid-19 testing appeared to step back from Mr Hancock’s promised 100,000 virus tests each day.

Professor John Newton told ITV’s Peston programme the Government was confident that only “if there are enough people who need testing then we will hit our target”.

Meanwhile, First Secretary of State Dominic Raab told reporters there was “light at the end of the tunnel” after it was confirmed the UK had reached the peak of infections.

It comes as:

– The Government announced a new study to track Covid-19 in the population in a bid to understand the current rate of infection.

– Foreign Secretary Mr Raab said the British public would accept the invasion of privacy entailed by the NHS coronavirus smartphone app which can trace their movements.

– Backbench Tories increased the pressure on the Government to scale back the lockdown over fears prolonged restrictions could sink the economy.

– The armed forces will be used to scale up testing as ministers mull how to lift social distancing restrictions.

According to the Times, Tory MPs vented concerns about the impact the lockdown was having on the economy during a gathering of the backbench 1922 Committee on Wednesday, as Parliament continued its new “hybrid” arrangement of operating with social distancing restrictions in place.

Sir Geoffrey Clifton-Brown reportedly called for a “gradual, step-by-step” easing of the lockdown in the next two to three weeks.

“That will inevitably mean that there will be, at each time, more coronavirus cases. And we just have to accept that,” the committee’s treasurer told the paper.

The lockdown measures are due to next be reviewed on May 7. Health Secretary Matt Hancock told the Commons he was preparing to ramp up contact tracing on a “large scale” as a way of keeping the virus under control once lockdown measures are eased.

The Government, along with the Office for National Statistics, has announced that 20,000 households in England are being contacted to take part in the first wave of the research designed to understand how the deadly bug has spread across the country, with initial findings expected in early May.

All participants will provide a nose and throat swab to test for whether or not they currently have the virus, while adults in some 1,000 of the households will provide a blood sample to find out what proportion of the population has developed antibodies to Covid-19.

In the Commons on Tuesday, Mr Hancock said he was confident the country was at the peak of the outbreak but stressed that continued social distancing was currently needed to bring the number of new cases down.

He also said a contact tracing app which will alert people if they have been in contact with somebody with the virus and should self-isolate was currently in trials.

The BBC reported that testing of the new technology was being carried out at RAF Leeming, a base in North Yorkshire.

The broadcaster said the app currently tells users “you need to isolate yourself and stay at home” if they are deemed to be showing symptoms or have come into close contact with another app user who has Covid-19 symptoms.

General Sir Nick Carter, chief of the defence staff, said armed forces personnel were involved in rolling out “pop-up” testing centres as part of efforts to test those living even in remote areas of the country.

The Department of Health said 18,100 patients had died in hospital after testing positive for coronavirus in the UK, as of 5pm on Tuesday, up by 763 from 17,337 the day before.