Read on Twitter
So there's your 0.4. what we presumably don't know yet (since this variant was quite localised) is whether that's entirely down to differences in the virus or partly down to regional differences in e.g. people's behaviour. https://twitter.com/whippletom/status/1341079218508222464
But let's say for argument's sake it's all down to the variant. A +0.4 effect on R would mean we'd need the level of lockdown than would have previously got us to R=0.6 to keep it under 1.
But if (as seems more likely?) it's a proportional increase of +50% then we'd need measures that would have previously got us to R=0.66. That might actually be an important difference!
This article says that in lockdown 1 we got R down to 0.57. If we need 0.6 that doesn't give us much wiggle room given that it's winter now and people are *tired*. 0.66 might be more achievable... https://news.sky.com/story/coronavirus-englands-r-number-dropped-lower-than-reported-in-lockdown-study-12028854
