One dengue vaccine is currently licensed, Sanofi SA's Dengvaxia, with Mexico in December becoming the first country to give it approval.
Marie-Paule Kieny, WHO assistant director-general for health systems and innovation, says the U.N. health agency's response is "proceeding very quickly"
Doctors analyzed data on nearly 6,200 health care workers over two flu seasons at one teaching hospital in Mexico.
This would be the world's first licensed malaria vaccine, even though it's only about 30 percent effective and its protection fades over time.