An experimental single dose vaccine against the Zika virus has proven to be powerful in mice, new research has found. The vaccine employs an uncommon two-pronged approach to fighting the virus, which is spread by mosquitoes and is most serious for pregnant women and their foetuses. The vaccine, carrying genes for two or three Zika proteins, proved effective in triggering an immune response that prevented later infection by the virus.
“The vaccine was potent, safe and highly effective, at least in the short term. There’s a long way to go, but we think this is a promising candidate for a human vaccine,” said lead author Jianrong Li, a professor at The Ohio State University in the US.
The experimental vaccine holds particular promise because it appears to afford an adequate immune response with one dose. In hard-to-reach and resource-poor areas, that becomes especially valuable, added Shan-Lu Liu, co-author at the varsity. In the study, appearing in the journal Nature Communications, the team targeted a protective immune response by expressing two or three Zika proteins and looked to vesicular stomatitis virus, or VSV — a foot-and-mouth disease in cattle.
In the experimental vaccine, VSV acts as a vehicle to deliver the genes for two or three key proteins from the Zika virus, carrying them into the mouse and expressing them inside some of the cells in the mouse so that the immune system could respond and build up a defence against Zika.
In addition, experiments in mice with severely compromised immune systems showed that vaccination helped their weak immune systems to fight off the virus swiftly and efficiently.
The early success with this vaccine has encouraged this team to use the same approach to fight other related viruses, including Dengue fever, the researchers said.
However, the next big question is “will this be protective in humans?”, the researchers said.