Recent reports suggest that Indian scientists at the National Center for Biological Sciences (NCBS)-Tata Institute of Fundamental Research in Bengaluru have developed a DNA vaccine candidate against dengue virus.
The researchers selected a portion of the most important viral protein, called EDIII, from all four serotypes of the virus. They also selected the NS1 protein from the DENV2 serotype, which is known to cause severe dengue.
The study, titled ‘Immune Profile and Response of a Novel Dengue DNA Vaccine Encoding EDIII-NS1 Consensus Design Based on the Indo-African Sequence’, published in MedRxiv, explains the major problems faced by scientists in developing dengue vaccine .
Study author Dr Arun Shankardas said, “In conventional vaccines, whole envelope proteins are used, which can lead to antibody dependent enhancement – ADE (where the viral antigen binds to the less effective antibody making the virus more effective). ).”
“We only used domain III of the envelope protein from all four serotypes to avoid ADE. We added the NS1 protein which is known to generate both T cell and B cell responses,” he adds.
Prof Sudhir Krishna, senior author and anchor, Dengue Vaccine Development Program at NCBS in Bengaluru, explains, “We know that the virus has four serotypes, but we found that there were genetic variations within the serotypes. Any sequence with a difference of more than 6 percent is considered a distinct genotype. The team created a consensus sequence that is also identical across genotypes.”
In addition, he stresses the need for more collaboration, “including the Translational Health Science and Technology Institute (THSTI), Rajiv Gandhi Center for Biotechnology and NIMHANS, to bring teams across India to work together.”
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