Over 80% new U.S. infections caused by newer Omicron subvariants


Newer and most contagious Omicron subvariants, known as BA.4 and BA.5, make up more than 80% of current Covid-19 infections in the United States, according to data released by the U.S. Centers for Disease Control and Prevention (CDC).

The BA.5 subvariant accounted for 65% of new infections in the latest week ending July 9, while BA.4 accounted for 16.3 per cent of new infections, CDC data showed Tuesday.

BA.5 has become the dominant variant in the U.S., news agencies reported. Confirmed cases contracted by the two subvariants have kept increasing since mid-May, CDC data show.

The two subvariants are more contagious than earlier variants of Omicron, and also appear to evade protection from vaccines and previous infections more easily than most of their predecessors, according to health experts.

“Cases are rising again in the U.S., and could rise substantially later this summer or in the fall, when there is a return to offices, schools, and other indoor facilities,” Jeffrey Sachs, professor and director of the Center for Sustainable Development at Columbia University, told Xinhua in a recent interview.

Experts stressed that current public health tools, including masking indoors, avoiding crowds and getting booster shots, are still effective against severe illness, hospitalisations and deaths caused by BA.4 and BA.5.