UF researchers detail new tactics against Zika, other viruses

Mosquito biting human flesh
Anopheles gambiae, AFPMB, (CC BY-NC-ND 2.0)

University of Florida scientists presented new research Sunday outlining ways to prevent the spread of the Zika and dengue viruses through the development of a Zika vaccine and a focus on spraying indoors to control mosquitoes.

Ira Longini, Ph.D., a professor in the department of biostatistics at the UF College of Public Health and Health Professions and the College of Medicine; and Natalie Dean, Ph.D., a post-doctoral associate in the department of biostatistics,, organized the panel during the American Association for the Advancement of Science meeting in Boston.

“This session was really about state-of-the-art approaches to controlling Zika and dengue,” Longini said. “Currently, we have a dengue vaccine and we have indoor residual spraying — two methods we could use to curtail transmission.”

Indoor residual spraying involves spraying for mosquitoes in hot spots inside people’s homes — the backs of closets and other dark, cool places where mosquitoes like to linger. Indoor residual spraying works because it places the insecticide where the mosquitoes are actually biting people, according to Longini. The spray remains effective for several months.

“Indoor residual spraying is probably the only vector-control method known to work for any arboviruses,” he said. Transmission of Zika, chikungunya and dengue would all be reduced through effective use of this technique.

The scientists also discussed efforts to make an effective Zika vaccine. There are many Zika vaccine candidates, several of which have the potential to move on to phase III trials. During this phase, the efficacy of the vaccine is tested on a relatively large group of people — typically several thousand.

The Zika virus is closely related to dengue, and much of the research about reducing Zika transmission initially sprung from the idea that what works for dengue might also work for Zika.

“The goal is to find evidence-based approaches for how to deal with Zika and dengue,” Dean said.

Wolbachia, a bacterium that infects insects, is another option scientists are considering to reduce the spread of dengue. Studies have shown that Wolbachia infection reduces dengue virus replication. Furthermore, when male Wolbachia-infected mosquitoes mate with females, the females are unable to reproduce. These bacteria may be able to help reduce the population of Aedes aegypti, the yellow fever mosquito.

Three speakers took art in the panel: Nicholas P. Jewell, Ph.D., a professor of biostatistics and statistics at the University of California, Berkeley School of Public Health; M. Elizabeth Halloran, M.D., D.Sc, a professor of biostatistics and epidemiology at the University of Washington School of Public Health; and Gonzalo M. Vazquez-Prokopec, Ph.D., a professor in the department of environmental sciences at Emory University.