Team develops promising Zika vaccine candidates

Researchers around the world have been racing to develop a vaccine for the Zika virus, and it appears that a large team of US researchers have developed two very promising candidates.

According to a report published in the journal Nature, researchers developed one potential vaccine using a Zika virus isolated in Brazil, and another candidate using a Zika virus isolated in Puerto Rico. Preclinical results showed both candidates were able to protect mice against an infection with the Zika virus by stimulating the rodents’ immune system. Furthermore, neither candidate was found to have significant side effects.

One of the candidates, a purified inactivated virus vaccine (PIV), was developed by researchers at the Walter Reed Army Institute of Research (WRAIR) and this potential vaccine will be the first to move forward because it is based on a kind of vaccine that has prior approval to treat other flaviviruses, a genus of viruses that includes the West Nile virus, dengue virus and the Zika virus.

Mosquito sucking blood

The mosquito-borne illness has become one of the world’s most pressing health risks. (Image credit: Thinkstock)

Working with proven technologies

In a news release, Army officials said their scientists are trying to tamp down risk by steering clear of unproven technologies that could trigger a licensing delay.

“This critical first step has informed our ongoing work in non-human primates and gives us early confidence that development of a protective Zika virus vaccine for humans is feasible,” Col. Nelson Michael, the WRAIR Zika program co-lead, said.

WRAIR researchers are moving quickly to formulate and test the PIV vaccine, and they said they intend to start human clinical trials before the end of the year. Even more human trials are being planned by the National Institute of Allergy and Infectious Diseases (NIAID), through its Vaccine and Treatment Evaluation Units.

“Our laboratory in Thailand has been conducting biosurveillance for Zika for the past three years, since we started to observe dengue-like illnesses in Thailand and the Philippines that were not dengue and did not test positive for other likely causes,” Thomas said. “These efforts gave us a head-start for our vaccine development efforts.”

Infectious diseases have long been a menace to US military personnel, and the military has extensive skills and abilities in developing countermeasures. WRAIR is focusing on a Zika vaccine together with other government agencies.


Image credit: WRAIR