At Least Seven More Years To Develop Safe Dengue Vaccine

BANGKOK, March 22 (Bernama) -- It will probably take another seven years before a dengue vaccine which is safe and effective against all four strains of the dengue virus can be produced, an expert said ahead of a World Health Organisation's (WHO) Dengue Prevention and Control in Asia Pacific Conference in Chiang Mai.
Professor Duane J. Gubler, Director of Hawaii-based Asia Pacific Institute for Tropical Medicine and Infectious Disease, said that there were five to six vaccine candidates on trial now but many challenges were delaying its mass production.
"We made a commitment 30 years ago during a meeting in Singapore to develop dengue vaccine. But we still have a few more years before we can really use it as a shield against the mosquito-borne disease," he told a press conference, here Wednesday.
Dengue fever is transmitted by the Aedes aegypti mosquito, which bites during daylight hours.
Gubler said it was important to develop the vaccine earlier as the dengue endemic would get worse this century due to the rapid growth in population, globalisation and urbanisation.
Among institutions in the advanced stage of developing the vaccine were Thailand's Mahidol University and Walter Reed Army Institute of Research (WRAIR), said Gubler, adding that the Bill Gates Foundation had also given a grant of US$55 million for dengue research.
He said among challenges facing researchers were that animals were not a good model to test the vaccine.
According to reports, a modern dengue vaccine was first produced at WRAIR in the late 1970s to early 1980s and co-developed by GlaxoSmithKline Biologicals.
The vaccine being developed at Mahidol, which received a US$10 million grant from WHO 10 years ago, is still in the process of human trials.
Dr Kevin Palmer, WHO's Regional Adviser for Malaria and Vector-Borne and Parasitic Diseases, said before 1950, dengue epidemics in the region occurred at an interval of 10 to 20 years but were now occurring between two and three years. He said it was now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, Southeast Asia and the Western Pacific, adding that it was spreading to previously unaffected countries like Bangladesh, Bhutan and Queensland in Australia.
"In the past, it was an urban disease but is now spreading to rural areas where the poor live and lacked good medical facilities. Without proven vaccine, prevention is the best measure now," he said.
Palmer said community involvement and good case management were vital in tackling the problem and cited Malaysia and Singapore as good examples on how well-planned programmes were carried out effectively to deal with the dengue outbreak.
On the Chiang Mai conference, Palmer said experts from various United Nations agencies and potential donors like Asian Development Bank would review the current situation of dengue in Asia Pacific and try to raise fund to fight the disease.
"The problem is, people and political powers forget dengue after the end of an outbreak. It's also not getting enough publicity in the west because of the perception it's confined to this region. We hope to get the same commitment as the support given to fight avian flu," he said.
In the western pacific region, 1.8 million cases of dengue were reported between 1991 and 2004, with the case fatality rate of 0.5 percent.
WHO said countries reporting maximum cases of dengue include Vietnam, Malaysia, the Philippines, Cambodia, Laos, Singapore, French Polynesia, New Caledonia and China.