Getting dengue first may make Zika infection much worse

Cell, mice experiments reveal antibodies gone rogue

dengue antibody and dengue virus

FRIEND OR FOE   A dengue antibody (blue, shown bound to a dengue virus protein, red, in this molecular model) can ease Zika’s entry into cells, a new study finds.

Laguna Design/Science Source

Being immune to a virus is a good thing, until it’s not.