SHORT THREAD: with a couple of big take home messages and some *speculation* on the VOC. This study confirms our worst fears regarding the degree of transmission advantage for the variant of concern. 1/n

The study:

https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2020-12-31-COVID19-Report-42-Preprint-VOC.pdf

We are seeing increases in R(t) of between 0.4-0.7, which can also be expressed as a multiplicative advantage on R of between 50 and 75% percent. This variant will lead to tens of thousands more deaths unless we take drastic measures now and roll out the vaccine quickly. 2/n

There is also, unfortunately, statistically significant evidence for more circulation in the under 20s. This is where the speculation starts. We will probably never know exactly how the VOC came about. 3/n

One possibility is the immunocompromised patient hypothesis, another is that the virus has been circulating freely, unrestricted, in the under 20s due to the failure of UK lockdowns to limit transmission in educational settings in a meaningful way. 4/n

What next? We must take drastic measures here. By allowing primary schools to open in a 'business as usual' way next week in the UK, we are basically trying our luck here, both in an epidemiological, and an evolutionary sense. 5/n