By ROBERT LANGRETH | Bloomberg | Published: February 1, 2021 Stars and Stripes is making stories on the coronavirus pandemic available free of charge. See other free reports here. Sign up for our daily coronavirus newsletter here. Please support our journalism with a subscription. A COVID-19 mutation that likely confers partial resistance to the antibodies produced by vaccines is now in the U.S., spurring scientists to probe new ways to battle a disease that's constantly changing and could remain active for years. The South African variant has already spread quickly across the African continent and has been seen in at least 24 countries outside of Africa. It was reported in South Carolina on Jan. 28 and in Maryland two days later. If that looks like just a beachhead, note that a U.K. mutation first seen in Colorado on Dec. 29 has been detected in 29 U.S. states in less than a month. Both variants are considered more contagious than the original strain.