U.S. stocks dropped sharply on Friday as a new Covid variant found in South Africa triggered a global shift away from risk assets. The Dow Jones Industrial Average dropped 905.04 points, or 2.53%, for its worst day of the year, closing at 34,899.34. The S&P 500 lost 2.27% to close at 4,594.62, while the Nasdaq Composite slipped 2.23% to finish at 15,491.66. The Dow was down more than 1,000 points at session lows. The downward moves came after World Health Organization officials on Thursday warned of a new Covid-19 variant that’s been detected in South Africa. The new variant contains more mutations to the spike protein, the component of the virus that binds to cells, than the highly contagious delta variant. Because of these mutations, scientists fear it could have increased resistance to vaccines, though WHO said further investigation is needed. On Friday, the WHO deemed the new strain a variant of concern and named it omicron....