Kristian G. AndersenGeverifieerd account

Several more genomes (n=19) have been released and this picture still holds true with a plausible (note, *lots* of caveats) median date of ~ early/mid-December.https://twitter.com/K_G_Andersen/status/1219280708188827649 …

This suggests little diversity in founding viruses: - Either a single animal infected many people, - Multiple animals with similar viruses caused the initial infections, - Or there was only very few crossovers which then spread through person to person transmission.

To me the lack of diversity strongly implies that this is primarily person-person transmission.

Yes, there's very little diversity in the population (~1 SNP / genome). We can't really distinguish small animal founder population infecting humans vs human-to-human - no SNPs are currently transmitted and we have a star topology.

It's clear from the epi data that human-to-human transmission does occur, however, we don't yet know how prevalent it is. Could be all cases (but 1) are H2H, could be a small subset. What we *can* conclude, is that people aren't being infected from a widespread animal reservoir.