Thread by @BillHanage

I think it is fair to say now that B.1.1.7 is definitely more transmissible, and possibly more virulent. This also reports cases that have acquired E484K, a mutation found in the other variants. This is concerning, but not reason to go crazy. A thread 1/n assets.publishing.service.gov.uk/government/upl…

First let's put to bed any suggestion that overdispersion in transmission explains B.1.1.7's rise. Consider data from Denmark, Ireland and now LA to mention only a few. It's behaving as we expect 2/n

https://twitter.com/DocJeffD/status/1356661499289161731?s=20

This is the weekly increase in England documented in the linked report since early October. It's quite interesting that it's not taken over completely but don't want to speculate why 3/n

The estimate is still that B.1.1.7 is about 50% more transmissible than previously circulating viruses, although I want to point out that the exact number might reflect something about contact patterns in the UK. The report includes interesting data from contact tracing 4/n

I recommend you read the report, but these differences are consistent with increased transmissibility, and while small they are remarkably consistent by region. They also seem a little higher for transmission to both direct contacts and close contacts 5/n

The report also states that 11 genome sequences were obtained in which B.1.1.7 has acquired E484K, a mutation that is also found in the other variants and has been implicated in reduced neutralization by convalescent plasma 6/n ncbi.nlm.nih.gov/pmc/articles/P…

Firstly this should not be very surprising. There have been a lot of opportunities for B.1.1.7 to mutate. Indeed it sounds like it has acquired the mutation at least twice. What is it likely to mean? 7/n

Well for a start we should remember that both B.1.351 and P.1 both have a number of *other* changes in addition to E484K that might be important contributors to their epidemiology. Oranges are not the only fruit and E484K is not the only mutation 8/n

Yes E484K may well have some impact on the virus's ability to reinfect, but that's not the same thing as entirely evading the immune system. And that goes for vaccine induced immunity too 9/n

There has been waaaaay too much reporting of E484K as heralding 'vaccine escape'. That's misleading. It may reduce the efficacy of some vaccines to some degree against some variants, but that's not the same thing as escaping them at all 10/n

People will vary in the immune response they mount following vaccination (or infection) and some will be more easily (re)infected than others. Some viruses will be better at it than others and yes, some of that will be because of specific mutations 11/n

basically what @pathogenomenick said 👇🏼12/n

https://twitter.com/pathogenomenick/status/1356688687858384904?s=20

I want to be clear that the report of the mutation is serious and the situation needs to be very closely monitored, but it would be wrong if I didn't point out that E484K has happened other times and the lineage has apparently gone extinct of its own accord 13/n

Finally this should be a reminder that viruses of concern don't only come from overseas. They can be generated in our own communities and the more transmission happens, the more likely that is 14/n theguardian.com/world/2021/feb…

So let's do whatever we can to slow transmission down, and place barriers in the way of the virus by vaccinating people. If the efficacy *is* any lower, we will need to immunize more to have the same effect, so let's get going 15/end