On 21 February 2011, NSTDA, Chiang Mai University, Mahidol University and BioNet-Asia Co., Ltd. announced a licensing agreement for chimeric dengue vaccine. The agreement will enable BioNet-Asia Co., Ltd. to further develop four serotypes of chimeric live-attenuated vaccine into a commercial product.
The four serotypes of dengue vaccine candidate were jointly developed by Assoc. Prof. Nopporn Sittisombut (Chiang Mai University and Medical Biotechnology Research Unit, BIOTEC), Dr. Poonsook Keelapang (Chiang Mai University) and Assoc. Prof. Sutee Yoksan (Mahidol University) with research fund from NSTDA.
Dengue is caused by four closely related viruses, dengue serotypes 1 - 4, which are single-stranded RNA viruses spreading primarily through the A. aegypti mosquito. A set of tetravalent, live-attenuated dengue vaccine was developed previously by serial passages of dengue viruses in appropriate mammalian cells. From the study, a number of modifications of genetic material in different regions of the genome of dengue serotype 2 was found to result in the attenuation of virus virulence. This discovery leads to the construction and testing of the chimeric viruses which comprise of the prM-E coding region from recent dengue clinical isolates on the genetic background of attenuated virus. Based on promising results from the neurovirulence and immunogenicity testings in mice, the chimeric viruses are considered to have a good potential to be developed further as vaccine candidate for the safety and efficacy studies in non human primate model.
BioNet-Asia Co., Ltd. is a biotech company based in Thailand with core business in the development and marketing of vaccines in the emerging countries. It is expected that this collaboration will lead to a commercial dengue vaccine available to Thais and expand to ASEAN market and beyond.