For how long Omicron has been circulating is an important question. Most estimates land ~mid October & identification of cases with no travel links to SSA indicates early evidence of community transmission. See threads by @K_G_Andersen & @trvrbhttps://t.co/TKawdpfiSe (4/n) pic.twitter.com/9Jfiq7b04S

— Muge Cevik (@mugecevik) December 3, 2021