NEW YORK — The U.S. government is buying more monkeypox vaccines as a surprising international outbreak continues to grow, health officials said Friday. As of Friday, the U.S. had identified 45 cases in 15 states and the District of Columbia. More than 1,300 cases have been found in about 30 other countries outside the areas of Africa where the virus is endemic. Officials say the risk to the American public is low, but they are taking steps to assure people that medical measures are in place to deal with the growing problem. A two-dose vaccine, Jynneos, is approved for monkeypox in the U.S. The U.S.