Thread by @LongDesertTrain

1/8 Fascinating and important study here. Finds that a Delta-specific vaccine could leave us vulnerable to Beta & similar variants, while a Beta-specific vaccine would leave us vulnerable to Delta. What can protect us from both? The Original Recipe D614G vaccine.

https://twitter.com/sigallab/status/1441029985397919754

2/8 Beta and Delta are far apart in evolutionary terms, so the effectiveness of antibodies against each are much reduced against the other—a 34-fold decrease in the case of Delta nAb's against Beta.

https://twitter.com/sigallab/status/1441030021498429440

3/8 Delta-specific antibodies also saw a 27-fold reduction in neutralization against a SARS-CoV-2 virus isolated from an HIV patient w/long-term infection. This virus had presumably evolved to evade the host's immune response. It's thought the Alpha variant originated this way.

4/8 But the current vaccines saw much less reduction in neutralization, seeing just a 2-fold reduction against Delta (somewhat smaller than the reduction seen in some other studies).

https://twitter.com/sigallab/status/1441030029333471241

5/8 This confirms what @profshanecrotty said in an excellent interview on TWiV w/@profvrr & friends: each vaccination dose improves our antibody response against variants, even if it uses the original D614G spike. See 54:08-55:48 (link starts at 54:08).

6/8 Another excellent segment from that @profshanecrotty interview discusses how our immune system creates variations of B cells designed to combat possible variants, yet another aspect of our immune system that amazes me. 40:10-42:36 Transcript below

7/8 Also a great discussion on boosters from 49:18-54:07. Transcript of the part from 49:18-51:24 below. Whatever you think of 3rd doses, I think it's hard to argue that they won't greatly decrease breakthrough infections this fall/winter and likely far beyond.

8/8 The whole germinal center discussion on that TWiV episode with Prof Crotty fascinated me, but I'm still fuzzy on the details of the process. Can anybody point me to a good primer on the subject?