Thread by @DrEricDing

📌VARIANT update on #MuVariant vs #DeltaVariant— it seems Ecuador #SARSCoV2 sequencing shows Mu variant competing well versus the Delta variant—both displacing all others. Lambda and Iota almost extinct. ➡️#MuVariant hanging on & expanding next to Delta.🧵
nextstrain.org/ncov/gisaid/so…

2) That said, in Colombia, where #MuVariant first emerged & once dominant, #DeltaVariant is outpacing Mu. Interesting Ecuador they are more or less tied, but in Columbia Delta is winning. Maybe because immunity against Mu has been building longer in Colombia—while Delta is new.

https://twitter.com/trvrb/status/1447566563532414988

3) What about #MuVariant vs #DeltaVariant in the US? It seems Delta is harder to control than Mu. Mu seems to rank second in R(t) — the R at current time — behind Delta. This is I guess good. But as Delta goes away, and we lift restrictions- will R(t) of Mu stay under 1? Dunno.

https://twitter.com/trvrb/status/1447566575125495809

4) Delta is generally much more transmissible than Mu. But notice how they sometimes overlap in some instances— that maybe there some situations where Mu can still keep pace with Delta. Hmmmm. Have to be watchful of both.

https://twitter.com/trvrb/status/1447566579646930944

5) again, we see other situations where #MuVariant definitely hangs on versus Delta, while Delta still faster that Mu most of the time in transmission.

https://twitter.com/trvrb/status/1447566584734572562

6) Let’s look at this graph by @ftzo more carefully… it does seem that Mu is on par with some subtype strains of #DeltaVariant, while Mu lags slightly behind other Delta variant subtype strains.

7) I agree with @trvrb’s analysis (he’s a @macfound Genius Award winner!) that if Delta wasn’t here at the same time, #MuVariant would likely be dominating the globe right now. This also suggests more variants could arise to displace Delta too once it drops. #vaccinate please.

8) Vaccine efficacy across variants generally similar (though #DeltaVariant is a tad lower below in purple)— but main problem is the huge drops in Pfizer efficacy with time to just 47% against infection after 5 months—waning is why we need the booster. thelancet.com/journals/lance…

9) That said, the vaccine’s effectiveness at preventing #COVID19 hospitalizations held steady at close to 90% for as long as six months. What’s more, it maintained that power across vaccine recipients of all age groups. latimes.com/science/story/…