BA.4, BA.5 gain ground in US, pose higher risk of breakthrough infections
enlarge † A person has a positive SARS-CoV-2 rapid test on February 17, 2022 in Berlin, Germany. Omicron subvariant BA.2.12.1 has overtaken BA.2 as the… Read More »BA.4, BA.5 gain ground in US, pose higher risk of breakthrough infections