EXPLAINER: BA.2 variant takes over. What’s known about it?

By LAURA UNGAR
AP Science Writer

An extra-contagious version of the coronavirus has taken over the world. The omicron variant called BA.2 is now dominant in at least 68 countries, including the U.S. The World Health Organization says it makes up about 94% of sequenced omicron cases submitted to an international coronavirus database. And the Centers for Disease Control and Prevention says it was responsible for 72% of new U.S. infections last week. One reason it’s gained ground: It’s about 30% more contagious than the original omicron. But it doesn’t seem to cause more severe disease. Vaccines appear just as effective against it, limiting hospitalizations and deaths.