Pitt Researchers: Previous Exposure To Dengue Fever Protects Against Zika

Feb 19, 2019

University of Pittsburgh researchers have found that previous exposure to Dengue Fever lowers the risk of infection from the Zika virus, which may have implications for maternal health.

The study was conducted with nearly 1,500 research volunteers residing in Salvador, Brazil, an "epicenter" of the 2015 Zika outbreak. Researchers found that each doubling of Dengue antibody levels corresponded to a 9 percent reduction in risk of Zika.

"What we don't know is how long this protection lasts," said Pitt's Ernesto Marques, the study’s senior author and an infectious disease expert. "We assume it’s for life, but we have only been observing for a very short time."

 

The World Health Organization says both viruses are spread through mosquito bites and are most often found in tropical and sub-tropic environments. 

 

Dengue infection results in flu-like symptoms that can sometimes be deadly while people infected with Zika don’t get very sick, if they become ill at all. The real danger with Zika is birth defects, such as underdevelopment of the brain or low muscle tone.

 

Currently there’s no Zika vaccine, but there is one for Dengue Fever. So Marquesz said, based on these results, OBGYNs might want to start giving the Dengue vaccine to women who plan to become pregnant.

“If we use currently approved Dengue vaccines or vaccines that are already close to become approved, you could boost Dengue responses... and could provide some degree of protection,” he said. 

Marques cautions though, that this theory needs to be tested. 

Cristina Cassetti is a virologist with the National Institute of Allergy and Infectious Diseases, which helped fund the study. She said when the Zika epidemic began there was concern that previous exposure to Dengue would make people more susceptible to Zika.

"So the study, for the first time, showed the contrary," said Cassetti.

Cassetti said this might provide the basis for creating a Zika vaccine, since researchers will now investigate how Dengue exposure provides protection. 

"What exact protein of Zika do they target? What antibodies generated are protected?" she said. 

The study was published this month in the journal “Science.”

WESA receives funding from the University of Pittsburgh.