For subtype BA.2, that analysis is still underway. "So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than omicron BA.1," said Chand.

Genetic variation within a subtype can be 15 to 20%, whereas variation between subtypes is usually 25 to 35%. 10 Over the past decade, advances in full-genome sequencing of HIV have led to the ...