There are some hints already as to which biological mechanisms might be in play with the apparent lower severity of the Omicron variant. The first obvious suspect is of course that it just seems less virulent because it infects people that have been vaccinated/infected by Covid already. But there's a 30% or so chunk of the South African population that still hasn't been either vaccinated or infected.
But recently it was found out that a) Omicron reproduces ten times more slowly than the original virus in lung cells, and b) it is almost incapable of generating syncitia - blobs of fused cells that viruses uses to better replicate and evade innate immune responses, a good correlate with severity in respiratory illnesses.
Edit - of course, as I said in a previous post, since this thing doesn't immunologically overlap much with Delta, you'll have both variants stacked one on top of the other in the middle of the Northern Hemisphere winter, when immunity is at its lowest. I'd recommend boosters to the elderly ASAP.
The best-case scenario would be an Omicron infection conferring at least temporary immunity to Delta. One-month immunity could be enough to break D's transmission chains when O is widespread enough.
Last edited by haxxiy - on 17 December 2021
