A ZIKA VIRUS VACCINE candidate is effective at preventing the Zika virus passing from mother to fetus in preclinical animal studies, according to a new study in the journal npj Vaccines.
The research is a collaboration between Trudeau Institute, Texas Biomedical Research Institute’s Southwest National Primate Research Center (SNPRC), and Walter Reed Army Institute of Research (WRAIR), where the vaccine was developed.
“The vaccine has been shown to be safe for non-pregnant humans, but of course, we need to know if it is safe and effective for the people at greatest risk: pregnant women and their fetuses,” says In-Jeong Kim, PhD, a viral immunologist at Trudeau Institute and the first paper author. “Our proof-of-concept studies conducted at Trudeau and Texas Biomed show very promising results that the vaccine given before pregnancy will provide high levels of protection for mothers and babies.”
The 2015-2016 Zika outbreak in Brazil and other countries in the Americas caused a surge in miscarriages and a constellation of birth defects, called Congenital Zika Syndrome, including abnormally small heads and neuro-developmental disorders. This prompted the World Health Organization to declare the Zika outbreak a public health emergency of international concern.
“It’s important to test vaccines before the next large outbreak because there will be another,” says Jean Patterson, PhD, a virologist at Texas Biomed and a senior paper author. “Zika is part of a family of viruses known to go through cycles. These viruses tend to spread rapidly through naïve populations that have never been exposed to the virus before, then infections drop-down for years because most people have been exposed. As more and more people are born, there is a new group of naïve individuals in which the virus can once again wreak havoc. We want to help break that cycle.”
The purified, inactivated Zika vaccine (ZPIV) candidate was developed by a team at WRAIR using the same technology they used to develop a Japanese encephalitis vaccine. The vaccine has been tested in non-pregnant animals, showing it effectively clears the virus from the blood. In Phase 1 human trials, it has been shown to be safe and elicit a protective immune response.
