COVID-19 could resemble the common cold by spring next year as people's immunity to the virus is boosted by vaccines and exposure, according to a leading expert.

Prof Sir John Bell, who was part of the team that developed the Oxford-AstraZeneca vaccine, tells Times Radio the country "is over the worst" and things "should be fine" once winter has passed.

He was speaking after Prof Sarah Gilbert, who designed the Oxford vaccine, said Covid was likely to become like other seasonal coronaviruses that cause common colds, as immunity in the population grows and the virus evolves.

Speaking to Times Radio, he says: "If you look at the trajectory we're on, we're a lot better off than we were six months ago.

"So the pressure on the NHS is largely abated. If you look at the deaths from Covid, they tend to be very elderly people, and it's not entirely clear it was Covid that caused all those deaths.

"And I think what will happen is, there will be quite a lot of background exposure to Delta (variant), we can see the case numbers are quite high, that particularly in people who've had two vaccines if they get a bit of breakthrough symptomatology, or not even symptomatology - if they just are asymptomatically infected, that will add to our immunity substantially, so I think we're headed for the position Sarah describes probably by next spring would be my view.

"We have to get over the winter to get there but I think it should be fine."