"Strain" is unfortunately an overloaded scientific term. In many circumstances every unique viral genome will be counted as a separate strain. If we use this criteria then we've seen 1150 "strains" out of 2243 #SARSCoV2 genomes currently up at https://t.co/JHWNUOwchc. 3/13

— Trevor Bedford (@trvrb) March 30, 2020