CHICAGO — Takeda Pharmaceutical Co’s experimental dengue vaccine was highly effective at preventing the mosquito-borne disease in a late stage study, but it failed to protect against one type of the virus in people with no prior exposure to dengue.was 80.2% effective at preventing dengue among children and teens in the year after they got the shot, according to results of a Phase III study published in the New England Journal of Medicine on Wednesday.
Experts have long been concerned that a dengue vaccine that is only partially protective could increase the risk of severe disease after exposure to a second type of the virus. There is an urgent need for an effective dengue vaccine. The tropical disease infects nearly 400 million people a year and kills up to 25,000 people.
But preliminary evidence suggests the vaccine failed to protect against dengue 3 in children and teens with no prior dengue exposure, and there was not enough evidence to make a call about its effect on dengue 4, researchers said.