Novel vaccine proven effective against Zika virus

A uniquely designed experimental vaccine against Zika virus has proven powerful in mice, scientists have found, paving the way for preventing the infection that causes babies to develop serious birth defects.

The vaccine, developed by researchers at Ohio State University in the US 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 single-dose vaccine, carrying the genes for two or three Zika proteins, proved effective in triggering an immune response that prevented later infection by Zika virus, researchers said.

"In this study, 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 Jianrong Li, a professor at Ohio State, who led the study published in the journal Nature Communications.

Babies born to Zika-infected mothers are sometimes born with a birth defect called microcephaly.

Other 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.

There's no vaccine available currently and the only protection against Zika are preventative measures such as insect repellant, staying indoors and wearing long sleeves and pants.

Shan-Lu Liu, a study co-author from Ohio State, said 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, he said.

The study included experiments in mice with severely compromised immune systems - a necessary step to make sure that mice could get sick after infection with Zika virus.

When the vaccinated mice were exposed to Zika virus, their weak immune systems fought it off swiftly and efficiently, convincing the research team that their design had worked.

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.