On relaxing the current restrictions, Prof Ferguson said: "What we really need is the ability to put something in their place. If we want to open schools, let people get back to work, then we need to keep transmission down in another manner.
"And I should say, it's not going to be going back to normal. We will have to maintain some level of social distancing, a significant level of social distancing, probably indefinitely until we have a vaccine available."
BBC health correspondent James Gallagher said
if a vaccine were to be found, it was not expected that manufacturers would be able to mass produce it until the second half of 2021.
"Remember, there are four coronaviruses that already circulate in human beings. They cause the common cold, and we don't have vaccines for any of them," he said.