BA.2.12.1 Is All “Revved Up”
This week, Allegheny County and 27 other counties in Pennsylvania find themselves hosting “high” community levels of COVID-19, according to CDC surveillance data. The United States experienced a steady rise of COVID-19 illnesses during the month of May, with the highest increases seen in the Northeast, Upper Midwest, and Florida. Infectious disease experts blame the springtime emergence of Omicron subvariants BA.2 and (more recently) BA.2.12.1, waning immunity from infection after vaccination and prior infections, and the lifting of mask mandates and other precautionary restrictions. Near the end of May, BA.2.12.1 became the dominant strain in the U.S., accounting for nearly 60% of new cases diagnosed (66% in Pennsylvania, according to Allegheny Alerts ). BA.2.12.1 is the most contagious variant of SARS-CoV-2 yet. Fenit Nirappil and colleagues expect problems after the warm and festive Memorial Day weekend: “This one is really revved up, and it’s probably getting up the...