The United States has reported a surge in cases of Omicron subvariant BA.2 in the last couple of weeks, according to the gene sequencing data of samples collected during this period. A San Diego-based gene sequencing company said that though the cases led by this variant of the virus have been growing slow in early January, the current estimate shows 50-70 percent of the cases reported currently are driven by Omicron BA.2 variant.