The first vaccine against dengue fever won clearance in Mexico, an initial step toward preventing a mosquito-borne infection that puts half of the world's population at risk.
Sanofi expects more approvals in "upcoming weeks" for the product, called Dengvaxia, in Latin America and Asia, Olivier Charmeil, who heads the Paris-based company's vaccines unit, said in a telephone interview. The injection can thwart all four types of the virus, which has appeared in Portugal, France, Florida and Japan recently and increased the risk of "explosive outbreaks," according to the World Health Organization.
Outbreaks are on the rise. Unlike malaria, another disease spread by mosquitoes, dengue affects wealthier urban populations in middle-income countries in Latin America and Asia in addition to poorer African nations. A water shortage in Sao Paulo prompted residents to store drinking supplies in pots and tanks, creating breeding grounds for mosquitoes and a dengue epidemic involving thousands of cases this year. In Hawaii, 139 cases have been confirmed in an ongoing outbreak, most of them in local residents.