12.05 pm: Dow advances more than 600 points     US stocks were higher in noon trading following reports from South Africa that the new coronavirus (COVID-19) Omicron variant is milder in nature.   At midday, the Dow climbed 603 points to 35,183, while the S&P 500 added 40 points at 4,579 and the tech-heavy Nasdaq gained 32 points to 15,117.
US stocks higher midday as Omicron concerns ease