Single-Dose Zika Vaccine Candidate Looks Promising
VSV is an excellent vaccine vector with an extremely high level of gene expression
A uniquely designed vaccine candidate against Zika virus has proven powerful in mice, said a team of researchers at The Ohio State University (OSU), in a press release.
These OSU researchers developed and tested a single-dose vaccine, carrying the genes for 2 or 3 Zika proteins, proved effective in triggering an immune response in mice that prevented later infection by Zika virus, according to the study, which appears in the journal Nature Communications.
This research is important since there’s no Zika vaccine available today.
Babies born to Zika-infected mothers are sometimes born with a birth defect called microcephaly. Other pregnancy-related complications include miscarriage, stillbirth and other birth defects.
Research also suggests that a small percentage of people infected with the virus can contract Guillain-Barre syndrome, which affects the nervous system.
The only protection against contracting Zika are preventative measures, such as insect repellent, staying indoors and wearing long sleeves and pants when outdoors.
Zika is a member of the virus family Flaviviridae, which also includes other globally prevalent human pathogens such as dengue, yellow fever virus, West Nile virus, and Japanese encephalitis virus.
“There’s a long way to go, but we think this is a promising candidate for a human vaccine,” said Jianrong Li, DMV, Ph.D., an Ohio State professor of veterinary biosciences who led the study and developed the vaccine platform.
When this study began, the Ohio State team wondered if a novel approach to vaccination might prove effective against the virus – one in which they targeted a protective immune response by expressing two or three Zika proteins.
As a vehicle for the Zika proteins, they looked to vesicular stomatitis virus, or VSV, which is a foot-and-mouth disease in cattle. The weakened form of the virus is harmless in humans and mice.
In this experimental vaccine, VSV acts as a vehicle to deliver the genes for 2 or 3 key proteins from the Zika virus.
“It’s a good platform for human vaccines because people don’t have any antibodies against it and that allows VSV to successfully transport the vaccine without being stopped by the immune system,” said study co-author Mark Peeples, a pediatrics professor at Ohio State and researcher at Nationwide Children’s Hospital in Columbus.
Recently, several Zika vaccine candidates have been reported, including nucleic acid (DNA and mRNA), inactivated virus, subunit, VLP, vectored vaccines (including adenovirus and vaccinia virus), and live attenuated vaccines.
Although these vaccine candidates are promising, the continued exploration of other new Zika vaccines is needed, said these researchers
Other Ohio State University researchers who worked on the study are Jingyou Yu, Mijia Lu, Yuanmei Ma, Zayed Attia, Miaoge Xue, Xueya Liang, Kelsey Craig, Nirajkumar Makadiya, Jingyang He and Ryan Jennings.
No conflicts of interest were disclosed by these researchers.