As the constant waxing and waning of COVID-19 rates in the United States continues, a pair of relatively newly identified subvariants of Omicron are suddenly being blamed for a growing proportion of new cases. BA.4 and BA.5 accounted for 5.4% and 7.4% of new cases, respectively, in the most recently weekly recap from the Centers for Disease Control and Prevention. After first being identified in South Africa, the pair have been gaining ground in the U.S. since April. A federal health official told NBC News that they’ll likely become the dominant SARS-CoV-2 infectants in the country by early autumn. This is significant because the short history of COVID-19 has shown that new variants tend to be more transmissible, though not necessarily more deadly or likely to cause serious illness, than their predecessors.
New Omicron Variants Have Landed in the U.S.—and They’re Moving Fast