New evidence that dengue antibodies trigger life-threatening infections

Source: Science Magazine

It’s a disease theory fit for a spy novel: Protective antibodies can turn double agent, teaming up with the dengue virus to make an infection more severe, even life-threatening. First proposed more than 40 years ago, antibody-dependent enhancement (ADE) has won over many doubters but still has impassioned skeptics. Now, a finding from a large, long-term study in Nicaraguan children adds compelling evidence that ADE is real, occurring when people previously infected with dengue—and with the right level and type of dengue antibodies still in their blood—become infected again.

“It wasn’t my life mission to prove or disapprove ADE,” says molecular biologist Eva Harris of the University of California, Berkeley, who started the study to better understand dengue epidemiology and pathology. “We kind of stumbled into it. And I never was really convinced until these data.”

Dengue, spread by mosquitoes, sickens up to 100 million people each year, mostly in tropical regions of the world. The virus has four “serotypes,” each of which triggers a unique antibody response. Someone infected for the first time with any of the serotypes typically has a mild, flulike disease that causes fever and muscle pains but does not require hospitalization. But those who become infected with a second serotype later are at risk of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), which can cause massive fluid loss, organ failure, and death.