A mainland-manufactured vaccine for Japanese encephalitis will be tested for possible use in Asia under a US$27 million grant from the world's richest couple, Bill and Melinda Gates. Project director of the Seattle-based Children's Vaccine Programme, Julie Jacobson, said the vaccine development was being fast-tracked as immunisation of children seemed to be the only option to control the virus. Japanese encephalitis, which put a 38-year-old Yuen Long woman in intensive care last month, has spread fast in Asia, killing one in three of those infected. Most of its victims are children under 15. Almost half of the survivors are left with a long-term disability, including paralysis, seizures and mental retardation, said Dr Jacobson in a telephone interview from Seattle. The mosquito-borne disease attacks the central nervous system, leading to inflammation of the brain's membranes. Dr Jacobson said: 'Vaccination is the answer to Japanese encephalitis. A lot has been done worldwide to eradicate mosquitoes, but they [the methods] do not work.' She said once a reliable and effective vaccine is found for mass production, the foundation would lobby the World Health Organisation to include Japanese encephalitis in the mandatory childhood immunisation programme. She added that three weeks ago she had visited the Beijing doctor who developed the vaccine and asked for documentation for the vaccine testing to proceed.