Thread by @Morbillivirus

It's #SARSCoV2 #Omicron time! We have some hopefully significant findings on neutralising antibodies (nAbs) in the 70-89 age group, a group who are at high-risk from #COVID19 medrxiv.org/content/10.110…

The @vGlycoproteins team, including @pizza_regret and @The1stNazerick (joint 1st authors) have looked at neutralisation of >20 different #SARSCoV2 Spike proteins from across the globe🌏🌍🌎!

Sera is from an elderly cohort, vaccinated with Pfizer 3 weeks apart.

Getting to the last figure first, of course #Omicron. At 3 and 20-weeks post 2nd dose the nAb response to Omicron is pretty much non-existent. However, at 4 weeks post 3rd dose (aka #BoosterJab) all people had detectable neutralising antibodies, which is good news 🙏👍

Left graph is the 70-79 age group (solid circles) and right graph is 80-89 age group (open circle). Red dot person is N ELISA positive. Comparing ELISA to nAb titre we see clear evidence for the #BoosterJab having a big effect.

However, this isn't our whole story. We also looked at 20 other Spikes to try and understand #SARSCoV2 antigenicity. All these Spike constructs and the funky figure were made by @PeacockFlu as part of the UK #G2P consortium.

For some of the less well known VUIs we got some pretty interesting results, including a small improvement in neutralisation for AY.4.2 (vs. Delta) which we weren't expecting. Aside from #Omicron C.1.2 looked the worst.

The #VOC nAb titres were consistent with what's been seen so far, but the low starting titres in this particular cohort make Beta look pretty bad... well at least until Omicron came along! Graph key A/A

At a more technical level we confirmed by RBD-ELISA that likely a significant part of this escape is down to Abs failing to bind epitopes changed by 484 substitutions in #SARSCoV2 Spike

This was a great team effort with scientists from #UKHSA, University of Surrey and Imperial College London. Thanks to everyone involved!!!👍👏👍👏