By Mrinalika Roy and Emma Farge GENEVA (Reuters) -Countries should take quick steps to contain the spread of monkeypox and share data about their vaccine stockpiles, a senior World Health Organization official said on Friday. “We think that if we put in place the right measures now we probably can contain this easily,” Sylvie Briand, WHO director for Global Infectious Hazard Preparedness, told the U.N. agency’s annual assembly. Monkeypox is a usually mild viral infection that is endemic in parts of west and central Africa. It spreads chiefly through close contact and until the recent outbreak,…