School children in the Philippines are no longer receiving a vaccine for dengue virus after the manufacturer announced people were at risk for developing more severe cases of the disease if they hadn't been previously infected with the virus before immunization, reports the New York Times. The Dengvaxia vaccine by Sanofi Pasteur is currently the only licensed one for the virus in the world.
Why it matters: As many as 390 million people around the world are infected each year with dengue virus. Most who are treated can survive the disease but in some cases it turns into a hemorrhagic fever that can be deadly. In the Philippines, more than 730,000 school-aged children have been vaccinated with Dengvaxia as part of a nearly $70 million government-funded immunization program. It appears the Dengvaxia vaccine makes hemorrhagic fever more likely.