Professor Neil Ferguson, whose modelling led to a complete shutdown in March and April, said he was confident vaccinations would lead to social distancing being lifted.
He told a symposium yesterday hosted by the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA) at Imperial College, where he works: "I think it will vary from place to place, but in the UK or much of Europe, I think we will see a very difficult two or three months ahead as we go through winter.
"But as we get substantial numbers of people vaccinated - remember you need two doses spaced basically a month apart before you get immunity, so I mean, from your first dose to getting immunity is typically about four or five, six weeks - so even if we start vaccinating now we have to go that much further.
"So in reality, we will have a difficult few months with similar sorts of measures in place that we have now through to the end of March, I would say, in much of Europe.
"At that point, both because of seasonality, but also because a lot of the most vulnerable people will hopefully then be protected, we will be able to relax social distancing measures and current restrictions quite nicely.
"I'm certainly hoping so. I'm looking forward to going on holiday myself in late April, maybe May."
However, Prof Ferguson said it would still take many months after that "to get truly back to normal".