Dr Chaturvedi has made original contribution to our knowledge of the immune response to Dengue virus infection. Starting with the epidemic of Dengue fever in Kanpur, Dr Chaturvedi extended his studies in the animal model and worked out the precise mechanism of immune-suppression mediated by factors induced by Dengue virus, thus opening up a new field of investigation using other virus models. These studies are valuable for obtaining a better understanding of Dengue Haemorrhagic Fever and Shock Syndrome prevalent in several parts of South-East Asia.