Vaccine against Dengue

After two decades of research, a vaccine for dengue is at last ready, courtesy the French vaccine manufacturer Sanofi Pasteur. The Mexico government has granted approval to the use of Dengvaxia for patients aged 9 to 45 years living in areas where dengue is endemic. The preventive vaccine is an injected three times over a period of six months. There are four serotypes of the dengue virus DV-1, DV-2, DV-3 and DV-4, and the breakthrough vaccine was found to produce antibodies against all four. In clinical trials in Latin America and Asia involving more than 40,000 children and adolescents, the vaccine was observed to give immunity to two-thirds of people aged 9 years. More significantly, it was most effective at protecting against severe dengue which can prove fatal — preventing 93 percent of such cases. No serious side-effects were observed during the trials, which was a major positive. Clinical trials were also conducted on Indian adults in Delhi, Ludhia, Bengaluru, Pune and Kolkata. But even though India has been hard hit by the dengue virus, it will be likely several months before dengue patients in the country are treated with the vaccine. Sanofi Pasteur has said the vaccine, being manufactured at two locations in France, is ready to be shipped to India. But Indian regulators will surely be observing how the vaccine works out in Mexico and await formal guidance from the World Health Organization, before taking the decision to import it. The French company has filed for approval of Dengvaxia in 20 countries where dengue is endemic, but questions about pricing remain. Reportedly, Sanofi Pasteur will set a price that would ‘reflect the value’ of the vaccine in terms of the savings it could bring about elsewhere. Since the total global cost annually of treating dengue is estimated to amount to 9 billion dollars while prevention strategies including mosquito nets cost a further 6-9 billion dollars, it will be interesting to see what formula the company applies to price its vaccine. This will be the most important factor if the vaccine is to be imported to India, where average 20,000 people every year are being hospitalised because of dengue, as per government figures. But the actual number of dengue hospitalizations in the country may be as high as 50 lakh, according to a study in 2014. Assam too has been affected by the dengue mece, carried by the Aedes Aegypti mosquito, with the parasitic disease bringing down mostly adults. A vaccine is good news for the State, provided it is affordable.