LONDON—Stock markets roared higher on Wednesday, reversing much of the previous session’s losses, as investors used the dip in prices to bet the latest COVID-19 variant would not derail the economic recovery. The EUROSTOXX rose 1.1 percent in early trading while Britain’s FTSE 100 rallied 1.3 percent and Germany’s DAX 0.75 percent. Wall Street futures pointed to a strong open. MSCI’s gauge of stocks across the globe was up 0.42 percent by 0900 GMT on Wednesday, having shed 1.5 percent the previous day, when investors took fright at a warning from drugmaker Moderna that existing vaccines are unlikely to be as effective against the Omicron variant. In Asia, stocks rose 1.1 percent as traders reversed course after a sharp selloff the day before took the regional benchmark to a 12-month low. “We expect market focus to gradually shift away from Omicron and toward positive growth and earnings trajectory, allowing equities …