An organisation that supports the development of vaccines against dengue fever is predicting they will be available in about five to seven years.
The Pediatric Dengue Vaccine Initiative says it supports seven companies, including three in developing countries, that are close to or are already testing their dengue vaccines on humans.
Last week, it agreed to help Hawaiian company, Hawaii Biotech, to develop a vaccine with a grant of 10 million US dollars.
The organisation's, Dr Richard Mahoney, says it wants to ensure that the vaccines will be available and affordable, especially to people in developing countries.
"We're doing that in a number of ways. One of them is to work with a number of companies, so that we can stimulate competition. Also, developing countries' manufacturers have demonstrated their ability to produce vaccines at lower costs, so that's why we give high priority to working with developing countries' manufacturers."
Dr Richard Mahoney