BA.4 and BA.5 Have Become Dominant Omicron Subvariants in the U.S.
On July 5, the Centers for Disease Control and Prevention (CDC) announced that two new subvariants of omicron, BA.4 and BA.5, have become the dominant strains of the COVID-19 coronavirus in all parts of the United States.BA.5 currently makes up 54 percent of new cases, with its sister subvariant, BA.4, accounting for about 16 percent of recent infections.In Europe, BA.4 and BA.5 are driving a summertime COVID-19 surge. Analysis of data by The New York Times showed that infections climbed to 57 cases a day per 100,000 people (as of July 6) from 33 cases a day per 100,000 people just two weeks earlier.In a media briefing on July 6, Dr. Michael Ryan, MPH, the executive director of the World Health Organization’s Health Emergencies Program, said that many European countries…