New discovery in Singapore may bring potential dengue vaccine

A research group led by Singapore 's Agency for Science, Technology and Research (A*STAR) on Tuesday announced their new discovery in crippling the ability of the dengue virus to escape the host immune system. The discovery, according to the scientists, could bring the world's first universal dengue vaccine candidate that can give full protection from all four serotypes of the virus. Besides the A*STAR's Singapore Immunology Network, the research also involves collaborations with Singapore's Novartis Institute of Tropical Diseases and Beijing Institute of Microbiology and Epidemiology. The dengue virus requires the enzyme called MTase, or 2'-O- methyltransferase, to chemically modify its genetic material to escape detection. The researchers then found that by introducing a genetic mutation to deactivate the MTase enzyme of the virus, initial cells infected by the weakened MTase mutant virus is immediately recognised as foreign. As a result, a strong protective immune response is triggered, and meanwhile, the mutant virus hardly has a chance to spread in the host. The researchers also demonstrated that the MTase mutant dengue virus cannot infect Aedes mosquitoes, which means that "the mutated virus is unable to replicate in the mosquito, and will not be able to spread through mosquitoes into our natural environment. " The team leader said their next step will be to work on a vaccine formulation that will confer full protection from all four serotypes with a single injection. "If this proves to be safe in humans, it can be a major breakthrough for the dengue vaccine field." Singapore experienced a dengue epidemic, with the total number of dengue cases reported so far this year at 14,363. This is significantly higher than the previous peak, though with fewer number of severe cases. After island-wide fighting for this epidemic, dengue cases these days have eased from the peak of 842 case per week. The total number from Aug. 4-10 was 258. However, the fifth dengue death was also reported on Tuesday.