A north Queensland tropical health expert says there is a long way to go before a potential dengue vaccine is ready for widespread use. A two-year study involving more than 10,000 children in the Asia-Pacific region found a drug was effective in preventing the mosquito-borne virus in 56 per cent of cases. The research was funded by drug company Sanofi Pasteur and published in the Lancet medical journal. The head of James Cook University’s tropical health and medicine division, professor Ian Wronski, says a longer study, and success rate around the 90 per cent mark, is needed. “It does have some effectiveness over the four sub-types and that’s good and it’s up from the traditional 30 per cent coverage that vaccines have had up until now,” he said. “So it is progress but it’s not there yet. “That’s way below something like 90 per cent which is what you’d be looking for. “In addition, I think the trial was followed for a couple of years. You’d really want a longer period of time because you’d want to be sure, for instance, that it didn’t trigger haemorrhagic fever.”