Tweet from trvrb at May 28, 2022 at 01:37PM
We now have enough co-circulation of Omicron sub-lineages BA.4, BA.5 and BA.2.12.1 in the US to make an assessment of relative fitness between these viruses. 1/12
— Trevor Bedford (@trvrb)
May 28, 2022
from http://twitter.com/trvrb