Cases of the BA.2 subvariant of ómicron increase in the United States and are already a third of covid-19 infections

WHO warns of spread of new variant of Omicron 2:24 (CNN) — Cases of the BA.2 subvariant of Omicron increased in March in the United States. Now, this variant represents more than a third of covid-19 infections in the country. The BA.2 subvariant of omicron caused about 34.9% of coronavirus cases in the United States last week. That compares to 22% in the previous week and 12% of cases in the week ending March 5, according to the US Centers for Disease Control’s (CDC) variant tracker. its acronym in English) that was updated early this Tuesday. Some regions have higher BA.2 infections than others. The BA.2 subvariant caused more than half of the infections in the Northeast last week, according to CDC data. The lowest rates of BA.2 infections last week, around 20%, were in the South and Midwest. What distinguishes the covid-19 BA.2 subvariant from the omicron? 0:54In recent weeks, the spread of the BA.2 omicron subvariant in the United States has slowed. After roughly doubling every week through February, BA.2 is now rising 10 to 12 percentage points week over week. The United States has seen slow but steady growth in BA.2 cases since January, even as overall cases, hospitalizations and deaths have decreased. Currently, the BA.2 subvariant has led to Covid-19 infections rising again in Britain and parts of Europe, where it has become the dominant strain of the SARS-CoV2 virus. Health officials have warned that BA.2, along with reduced mask use, may cause a rise in COVID-19 cases in the United States. Although also classified as an omicron, BA.2 is genetically distinct from BA.1. About 40 mutations separate BA.2 from BA.1, the original strain of the omicron variant, making it as distinct as the alpha variant was from delta.