UK PM Johnson says "open questions" on whether lockdown came too late

British Prime Minister Boris Johnson said on Friday there were open questions as to whether lockdown was introduced too late, as COVID-19 was poorly understood in its early stages.

Asked whether lockdown came too late, Johnson said: "When you listen to the scientists, the questions that you've just asked are actually very open questions as far as they are concerned.

"This was something that was new, that we didn't understand in the way that we would have liked in the first few weeks and months, and ... the single thing that we didn't see at the beginning was the extent to which it was being transmitted asymptomatically from person to person," he told the BBC.