Shot in the arm in fight against dengue: First vaccine on its way

New Delhi: The world's first effective vaccine against dengue could be available by 2015. Scientists have announced a major breakthrough, with a candidate vaccine recording a 60%-90% protection rate against three main virus strains (DENV 1, 3 and 4) that cause the disease.      The vaccine, CYD-TDV, was also found to be safe, with no serious side-effects on those who received it. Currently, no vaccine is available for protection against dengue, and efforts to develop one have been hit by the fact that the disease is caused by four different related viruses—DENV 1, 2, 3 and 4. The disease, which is caused by mosquitoes and is endemic in ove r 100 countries, also appears to be unique to humans. Hence, scientists cannot use animal models to test prospective vaccine candidates.      The findings will be published in British medical journal, The Lancet, on Tuesday. Using GM mosquitoes to kill mosquitoes W estern scientists have developed genetically modified mosquitoes which could be the new weapon in curbing mosquito numbers and fighting dengue. P 17 Dengue vaccine fails against deadly strain  New Delhi:In three years, there could be a vaccine to fight dengue. One of the researchers, Dr Derek Wallace from Sanofi Pasteur, said, "Our study constitutes the first ever demonstration that a safe and effective dengue vaccine is possible. Further trials of CYD-TDV are currently underway in a number of countries and our hope is positive results of this trial will be confirmed by these larger studies in a wide range of epidemiological settings."     Researchers based in France and Thailand said they had tested the effectiveness of CYDTDV on 4,002 Thai children aged between four and 11. Around 2,669 kids were given the CYD-TDV vaccine, while 1,333 were given a placebo. The vaccination schedule was three doses given six months apart.      Secondary tests showed the vaccine was effective against DENV 1, 3 and 4, but not DENV 2, which appeared to be resistant to the effects of the vaccine. Dr A C Dhariwal, head of India's National Vector-Borne Disease Control Programme, said, "A vaccine will greatly benefit India where children are major victims of this disease. This candidate vaccine protects against dengue virus strain 1 which is the commonest and strains 3 and 4 which causes mild manifestations. However, it is the strain 2 that causes dengue hemorrhagic fever which is life threatening. And this vaccine does not protect against this strain."