UK’s Johnson Says Lockdown Lifting Will Be Cautious but Irreversible

"We've got to be very prudent and what we want to see is progress that is cautious, but irreversible," Johnson told reporters. "If we possibly can, we'll be setting out dates."

"If because of the rate of infection, we have to push something off a little bit to the right - delay it for a little bit - we won't hesitate to do that."

Johnson, who will set out his plan to lift lockdown on February 22, said the rates of infection were still very high and that too many people were still dying.

"The risk is that if you have a large, as it were, volume of circulation, if you've got loads of people, even young people getting the disease, then a couple of things happen: first of all, you have a higher risk of variants and mutations within the population, where the disease is circulating," he said.

"Secondly, there will also be a greater risk of the disease spreading out into the older groups again," Johnson said.

"Although the vaccines are effective and great, of course no vaccination program is 100 percent effective, so when you have a large volume circulating, when you have got a lot of disease, inevitably, the vulnerable will suffer. So that's why we want to drive it right down, keep it right down."