For the first time, researchers have tested a Zika vaccine in animals that do not have a natural resistance to the virus. The synthetic DNA jab protected 100% of vaccinated animals from Zika infection, brain damage and death.
In the study, 100% of animal models were protected from Zika infection after receiving the DNA vaccine and undergoing a Zika challenge, the Wistar Institute said in a statement. They were also shielded from degeneration in the cerebral cortex and hippocampus, areas of the brain that were damaged in unvaccinated animals.
The candidate blocked infection by rallying an antigen-specific response from antibodies and T cells that neutralized the virus. And as a plus, it also prevented the virus from spreading to the brain, a significant step against a virus that can cause infected infants to be born with microcephaly, a birth defect characterized by an abnormally small head.
"Our results support the critical importance of immune responses for both preventing infection as well as ameliorating disease caused by the Zika virus," said lead researcher David Weiner, executive vice president and director of the Vaccine Center at Wistar, in the statement. "As the threat of Zika continues, these results provide insight into a new aspect of the possibly protective ability of such a vaccine as a preventative approach for Zika infection."
There is no approved vaccine or therapy against Zika, but the candidate, which is being developed by the Wistar Institute, Inovio Pharma and GeneOne Lifesciences, is the furthest along in development. It recently entered its second human trial and previously demonstrated success in mouse and monkey studies.A number of biotechs, as well as the NIH and Big Pharmas GlaxoSmithKline and Sanofi are testing different approaches to developing a Zika vaccine.