CDC data show another new secondary variable, BA.4, accounting for 12.8% of new infections.
Two infectious sub-strains now account for more than 90% of new infections in the United States.
CDC data shows that confirmed cases contracted with two extra variables continue to increase since mid-May.
Two sub-variants are more contagious than the earlier variants of Omicronand also seems to evade protection from vaccines and previous infections more easily than most previous vaccines, according to health experts.
Source: IANS
