Covid infections fell for a seventh day in a row, with scientists who predicted a devastating third wave now indicating that Britain will be over the worst of the pandemic by September.

Reported cases across the UK dropped by 1,439 to 23,511 – a decrease of 50 per cent since the same time last week. The seven-day figure of 229,828 is 30.8 per cent down from the previous week, with 102,240 fewer infections reported.

The percentage of people testing positive is also falling, while vaccination rates are climbing again for the first time in more than a month.

Prof Neil Ferguson – who previously predicted a summer peak of between 100,000 and 200,000 cases – said the downturn indicated that the pandemic would be drawing to a close by the autumn.

Prof Ferguson, of Imperial College and a member of the Government’s Scientific Advisory Group for Emergencies, said: "We’re not completely out of the woods, but the equation has fundamentally changed. The effect of vaccines is hugely reducing the risk of hospitalisations and death.

"And I’m positive that, by late September or October time, we will be looking back at most of the pandemic. We will have Covid with us, we will still have people dying from Covid, but we’ll have put the bulk of the pandemic behind us."

How many people have been vaccinated?

Scientists are unclear what is causing the dramatic fall but say it could be a combination of the school holidays, the good weather and the drop in social contact following the end of the Euro 2020 football tournament. 

Commenting on the figures, Dr Alasdair Munro, a paediatric registrar at University Hospital Southampton, said: "Cases are down absolutely massively, definitely not due to less testing as test positivity is also falling. However you cut this one, it’s bloody brilliant news."

Despite the fall in infections, hospital admissions and deaths are expected to continue rising for the next fortnight. Some 5,055 patients were in hospital with Covid in England on Monday, up 33 percent from the previous week and the highest number since March 18.

Deaths are continuing to rise, with 131 reported on Tuesday. However, the number of people actually dying on a given day is yet to rise above 76 in the third wave – far below the previous peak, when 1,359 people died on Jan 19.

Boris Johnson warned against drawing "premature conclusions", saying the easing of restrictions on July 19 may not be showing in the figures.

Speaking during a visit to Surrey Police HQ in Guildford, he said: "Step four of the opening up only took place a few days ago – people have got to remain very cautious, and that remains the approach of the Government."

Scientists say weekly infection survey data from the Office for National Statistics on Friday will give a better indication of whether prevalence is really dropping.

Prof Lawrence Young, a virologist and professor of molecular oncology at the University of Warwick, said: "While this drop in case number is good news, it has come as a bit of a surprise. On the plus side there is no question that the warm weather has contributed – more mixing outdoors, and the virus doesn’t like the sun – as has the increasing number of folk who are fully vaccinated.

"But are these case numbers an accurate reflection of infection levels in the community? It will be interesting to see what happens to case numbers over the next week to 10 days as we start to see the impact of the lifting of restrictions on July 19 and the new daily testing pilot scheme for key workers kicks in."