A study published in the British medical journal The Lancet suggests that a safe and effective dengue vaccine is possible. Hence, animals can't be used for vaccine trials.
Dr Derek Wallace from Sanofi Pasteur explained that CYD-TDV trials are being conducted in several countries, in a wide range of epidemiological settings. He assured that the positive results will soon be confirmed soon, as the extensive studies are underway. [Read: Treatment of Dengue Shock Syndrome]
France and Thailand based researchers tested effectiveness of CYD-TDV on a group of 4002 school children in Thailand, of age group 4-11 years. 2,669 children were given the CYD-TDV vaccine whereas 1,333 were given a placebo, to figure out the comparative effectiveness. The vaccination schedule constituted three doses of vaccine, which were given in a gap of 6 months. CYD-TDV vaccine was found to be effective against DENV 1, 3 and 4 (responsible for mild manifestations), but not on DENV 2 (associated with hemorrhagic fever).
Chairperson of India's National Vector Borne Disease Control Programme suggested that candidate vaccine will extensively benefit India where children are major victims of this disease.