Thread by @HsiaoMarvin

It’s been an intense and frantic week. I am exhausted but can’t sleep so might as well tweet about my thoughts on B.1.1.925 1/n

First the incredible duo @Tuliodna @rjlessells gave a really good media briefing. If you have not watched it it is worth your time. 2/n

As @jburnmurdoch and many others have pointed out, the most concerning aspect of the variant is the speed at which it is spreading and that it is displacing delta.

https://twitter.com/jburnmurdoch/status/1463956686075580421

But despite the exponential grow the number currently is still small by South African wave standards. This is because prior to the emergence of B.1.1.925, we had almost the lowest case count since the beginning of pandemic. 4/n

The reason for this new low nadir, in my opinion, is because we many people had some degree of immunity from past infection. Prior to the delta 3rd wave, our seroprevalence was already 50-60%. It would not surprise me if this number go up to 80%+ in November. 5/n

The SGTF data point toward variant emergence and rapid expansion in early to mid November. That’s 2 weeks ago. We now have more than 100 sequenced full length genome. Most people will not understand how insanely fast we had been by pre-pandemic standards. 6/n

So it is still early days and I think this is a wake up call that remind us pandemic is far from over. But in my mind not panic time. We have to watch hospitalization in the coming days for severity in our highly exposed population 7/n

We need to all do our bit to protect those who are vulnerable. Mask up and get vaccinated. Go for second dose or booster if it’s your turn. Socialize responsibly and remind each other of the risks of poorly ventilated, crowded places. 8/n

There are still many things to learn about B.1.1.925. For example I just found out earlier today that it’s mutations that result in the S69-70 SGTF is slightly different from VOC alpha on the nucleotide level. Clearly evolved from a different path. 9/n

Finally I have to take my hats off to my incredible colleagues. The tireless NGS-SA team, the iLEAD group at Wits/NHLS responsible for the national Ct/SGTF report, my epi and lab colleagues. Really silent heros doing amazing work 🙏 goodnight 10/n