Feature: Zika vaccine is next frontier in fight against Zika virus

Shannan Rossi, Ph.D., picks up a plastic vial, gently shakes it and looks closely at what it holds - the larvae of an Aedes aegypti mosquito whose species is rapidly spreading the Zika virus throughout the Americas.

"See that little wiggly guy in there? That's the larval stage that you usually see in a flower pot," said Rossi, a research scientist at the University of Texas Medical Branch at Galveston. "If you leave standing water around your house, you're gonna see a ton of them in a couple of days and they're going to want to bite you. And you're going to get a ton of mosquitoes all at once."

Rossi and her research colleagues at UTMB-Galveston are at the forefront of efforts to understand and control the virulent Zika virus, most commonly spread through the bite of an Aedes aegypti mosquito.

Rossi set up mosquito traps in her backyard in Galveston, where she collects mosquitoes for testing at UTMB. Last year, she travelled to Salvador, Brazil, to set up improved diagnostics for Zika, chikungunya and dengue in collaboration with the FioCruz Foundation.

Researchers at UTMB-Galveston are making headway in the battle against Zika, which was first isolated in 1947 in Uganda. The Zika virus emerged as a global concern after a series of outbreaks in 2007 across the Pacific followed by a dramatic spread in the Americas in 2014 and 2015.

Florida has become the epicenter for Zika in the United States, with 322 travel-associated cases of the virus and six locally acquired cases as of Aug. 3, according to the Centers for Disease Control and Prevention (CDC) in Atlanta.

In Harris County, which encompasses the Houston area, a baby born with microcephaly linked to the Zika virus has died in Texas, marking the state s first Zika-related death, the Texas Department of State Health Services reported on Aug. 9.

During her pregnancy, the mother was in Latin America, where she was infected, and the baby acquired the infection in the womb. The baby died shortly after birth.

Statewide, Texas has reported 99 cases of the Zika virus, including two infants with microcephaly from Harris County. All Texas cases are related to travel abroad to areas with active Zika transmission.

There have been no reported cases of the Zika virus transmitted by mosquitoes in Texas, but Texas is on alert for the possibility local transmission.

Across the United States, there have been 1,818 travel-associated cases of Zika reported, and six locally acquired mosquito-borne cases, according to the CDC.

The race for a vaccine has begun in earnest, with UTMB-Galveston helping to lead the way, said Scott Weaver, Ph.D, director of UTMB's Institute for Human Infections and Immunity, and scientific director of the Galveston National Laboratory.

"We're seeing rapid progress on vaccine development," Weaver said. "The first step was to make a DNA clone of the Zika virus, and that clone allows us to manipulate it genetically. Using mice, we are testing mutants of the virus made with clones to find ones that are attenuating (weakened).

Meanwhile, UTMB researchers have reported that a drug to treat Zika virus infections could already exist and be available on the market. A team of researchers tested over 770 different U.S. Food and Drug Administration approved therapeutics and found that more than 20 of those decreased Zika virus infection.

The team recommended that some of the drugs found to be effective against the Zika virus be considered for testing in clinical studies, but it would take some time before they are ready for clinical trials. There are no approved vaccines or specific therapies available yet.

Until a vaccine is found, health professionals are urging that people take precautions to avoid contracting Zika. The advice is especially crucial in Florida, where locally acquired cases have been reported.

"We should be concerned because there's a risk we could have local transmission here (Harris County)," Weaver said. "When infected travelers comes here, there's a chance they could initiate the cycle. We're seeing a lot of imported cases now, with the highest risk in Florida."

The best advice, he said, is to use some common sense.

"The important thing is to put the risk in perspective," Weaver said. "The individual risk is only to pregnant women and their partners. But the risk to everyone is influenced by travelers returning from affected areas who may not show the symptoms, but they could initiate mosquito-borne transmission.

"Those people really need to recognize that even though they feel fine they need to reduce their exposure," he said. Endit