The scientist whose modelling led to the first UK lockdown has said more future lockdowns are "unlikely".
Imperial College London's Professor Neil Ferguson told the BBC the UK is "likely to be on a steady course now out of this pandemic".
But the epidemiologist did warn there could be a withdrawal of some freedoms if any new variants proved resistant to vaccines.
The next step of the government's roadmap out of lockdown relies on the data supporting an easing of restrictions, ministers have said.
Professor Ferguson said that data on falling Covid case rates, hospitalisations and deaths was "encouraging".
He told the BBC that although a further lockdown "can't be completely ruled out", he has become "increasingly optimistic" in recent months.
"In the worst-case scenario, if we have a new variant pop up which does manage to evade the vaccines, say late summer/early autumn, there may be a need to roll back on some of these measures at least temporarily until we can boost people's immunity," he said.
"Do I think it's likely to happen? No, I don't. I think we are much more likely to be on a steady course now out of this pandemic, at least in this country."
He said new variants would need to be monitored "carefully", but the UK has gone from a "terrible situation" in January to a "remarkably good situation now".
Life would "feel a lot more normal" by early summer, he said, although questions remain over whether summer holidays abroad would be possible.
"We will have many fewer restrictions. Whether we have none at all it's too early to say," he added.
