Vaccine can prevent mosquito from transmitting dengue

Aussie scientists to help India reduce incidence of disease

Can mosquitos be injected with a vaccine to prevent them from transmitting the dengue virus to humans?

That’s what Australian scientists are working on. The scientists were in New Delhi looking for a partnership to help India, which reported the highest dengue cases — 37,000 — in 2012.

The Eliminate Dengue Research Programme is a not-for-profit international collaboration active in Australia, Vietnam, Indonesia, China, Singapore, Colombia and Brazil.

The scientists have transferred the Wolbachia bacteria from the fruit fly into mosquitoes, and found that when it is present in mosquitoes, it reduces their ability to transmit the dengue virus.

In a nutshell, scientists have vaccinated mosquitoes against dengue, as a result of which they will not be able to transmit it to humans. “Wolbachia acts like a vaccine for mosquitoes by blocking dengue virus transmission by them, and thereby preventing human infection with dengue,” said programme manager Peter Ryan.

The programme is managed by Melbourne’s Monash University. Ryan said the Wolbachia bacteria has the potential to be used against other insect- transmitted diseases.

“We have demonstrated that Wolbachia’s presence in mosquitoes reduces their ability to transmit other viruses such as chikungunya and yellow fever as well as parasites that cause malaria,” he said.

Explaining the science behind the research, Ryan said, “Our aim is to seed wild mosquito populations with bacteria through a controlled number of releases of Wolbachia-infected mosquitoes, which will then breed with the wild mosquito population.”

He said such an experiment was carried out in Australia’s Cairn area that has 1,000 houses in 2011. “In the past two years, we found that 80 per cent of mosquitoes cannot transmit dengue. But we cannot say if the number of dengue cases in humans has come down as we need a bigger sample size,” said Ryan.

Ryan, who was in New Delhi to attend a biotechnology conference, said they are ready to share the technology for free so that countries can innovate and develop it according to their biological and ecological conditions. “Dengue is a big problem and many people die of it. We want to provide a cost-effective and affordable way to countries to deal with the menace,” he said.

Scientists believe they have found a practical and environmentally sensitive approach to suppressing dengue with the potential for area-wide implementation at low cost.