1/5 Growing evidence that E484 variants (e.g. SA variant) can largely escape evenly strongly neutralising serum from first wave (in past week, by Andreano et al. https://www.biorxiv.org/content/10.1101/2020.12.28.424451v1 and by Greaney et al https://www.biorxiv.org/content/10.1101/2020.12.31.425021v1).

2/5 And that, while the Kent variant (N501Y del69/70) spreads faster [enhanced ACE-2 complementarity], its RBD mutation is not as deleterious to first wave antibody responses. Good thread: https://twitter.com/jcbarret/status/1343863090279043073

3/5 I’ve seen enough to think the current vaccines/a strong first wave response should work for N501Y alone (Kent) but not in combination with E484K (SA).

4/5 Evidence suggests the low-SHM/protective IGHV3-53/3-66 response (a commonly-believed “path of least resistance” for the immune system in response to the first wave) is rendered non-complementary by this charge switch in the centre of its epitopes.

5/5 ChAdOx2 should incorporate E484K (and possibly other mutations) and be ready for priority distribution to countries where E484 variants are now dominant (e.g. SA).