Prof Neil Ferguson, the epidemiologist whose initial modelling helped shape Britain’s coronavirus response, has said future lockdowns are unlikely to be needed to control the spread of the disease in the UK.

However, the government scientific adviser warned that Covid case numbers could rise again and his prediction could change if the virus “changes substantially”.

In an interview with the Times, Ferguson said it was still likely that there would be higher numbers of deaths each year than before as the world learns to live with the virus, much as deaths are caused by the flu each winter.

Ferguson, who stepped back from the Scientific Advisory Group for Emergencies (Sage) in May last year after a visit from his girlfriend that broke social distancing rules, but who remains on other government advisory committees, said it was “unlikely we will need a new lockdown or even social distancing measures of the type we’ve had so far”.

He said that, with a rise in social contact, Britain could “reach another point where we start seeing increasing case numbers again”, though at least vaccines had “changed the relationship between cases and hospitalisation”.

He also expressed sympathy for Matt Hancock after the disclosure of the former health secretary’s affair, which broke social distancing rules, rather than calling him a hypocrite for his criticism when Ferguson’s own private life made the headlines.

Overall, he said the UK, like elsewhere, would probably have to accept the continuing presence of Covid-19 as a potentially lethal threat.

“I suspect for several years, we will see additional mortality,” he said. “There’s a risk in the winter coming of thousands to tens of thousands more deaths.”

The epidemiologist said that if Boris Johnson had ordered the first lockdown a week earlier than he did in March last year, Britain’s first wave would have been been reduced by half and “maybe … by three-quarters”, saving more than 25,000 lives.

He said he understood the prime minister’s reluctance to shut down the economy at that point, amid uncertain modelling of the disease. However, he was less forgiving of the delay in locking down in the autumn, noting that about two-thirds of deaths in the UK from Covid have happened since 1 November.

The Imperial College immunologist said: “The idea that there was a trade-off between public health and the economy took hold in some elements of the political establishment,” but countries that had implemented measures earlier in the autumn had been able to lift them sooner.

Hancock had said he was “speechless” when news of Ferguson’s girlfriend’s visit broke – criticism that the scientist found “unnecessary” because he had already stepped down from Sage.

When closed-circuit TV footage was leaked of Hancock transgressing social distancing rules in an intimate embrace with a senior aide, Gina Coladangelo, Ferguson said he did not join in allegations of hypocrisy towards the politician.

“Actually, no, I didn’t. I felt very sorry for everybody involved. Being in the centre of that sort of media storm is horrific, even if there is reason for it,” he told the newspaper.

He added that while Hancock had lost his job, his own day-to-day life “didn’t actually change very much” after his scandal, which he admitted was a mistake.

“I just don’t think I was thinking,” he said. “I was working 18 hours a day and it hadn’t properly dawned on me that I was a public figure in that way.”