Vaccine group Gavi is set to launch a series of major measles vaccination campaigns to try to halt a global surge in the viral disease. It aims to immunize up to 45 million children in seven developing countries in Asia and Africa over the next six months. The GAVI vaccine alliance said on Wednesday it will work with governments and groups including the World Health Organization and UNICEF to target children under five years old the age group most vulnerable to the disease. Measles cases have risen dramatically in recent years. According to the World Health Organization measles had infected