A dengue vaccine, tested on 10,275 children in the age-group of 2-14 years in Asia, has shown an overall efficacy of 56.5 per cent, according to study reported in The Lancet. More trials of the vaccine are now being conducted in India.
While leading company Sanofi Pasteur is the main funder, the chief investigator has been identified as Dr Maria Rosario Capeding of the Research Institute for Tropical Medicine, Philippines.
India has witnessed a dramatic rise in dengue from 18,860 cases recorded in 2011 to 75,454 cases reported last year, according to data from the National Vector Borne Disease Control Programme (NVBDCP). Following the promising results of the study, another trial of the vaccine is now being conducted in India to examine its success.
According to officials from the NVBDCP, the compilation of the trial results will be done by Sanofi Pasteur in December this year, while the results will be announced in 2015.
Dr A C Dhariwal, director of NVBDCP, told The Indian Express, “It is good news for us. The trial is now going on in India and we will examine the results before making it part of our dengue prevention measures.”
The vaccine trial in Asia, which was in its phase III, was conducted in five countries — Indonesia, Malaysia, Thailand, Philippines and Vietnam — for 25 months. Children were given a three-dose vaccination schedule with an interval of six months. The trial results showed 88.5 per cent reduction in dengue haemorrhagic fever (a nearly fatal stage of dengue) and 67 per cent drop in need for hospitalisation due to dengue.
According to Sanofi Pasteur, the vaccine trial will now be conducted in Latin America and the Caribbean on over 20,000 children aged nine to 16 years.
The World Health Organisation (WHO) estimates close to 100 million dengue infections, caused by mosquito Aedes Aegypti, every year, of which maximum are reported from Asia and Latin America.
With no treatment in line for dengue, unlike malaria, the control and prevention of this disease has posed a major challenge.
Dr Om Srivastava, director of department of infectious diseases at Jaslok Hospital (Mumbai), said, “The count of dengue cases in the country is huge. Though the efficacy of the trial is not very high, it will still reduce the burden of dengue to some extent.”
According to the research in The Lancet, the vaccine has shown varying effects on the four different dengue serotypes with efficacy ranging from 34.7 to 72.4 per cent. Experts said dengue control through this vaccine can vary depending on the serotype.
Dr Kalpana Baruah, joint director at NVBDCP, said, “In India, serotype-1 is the most common dengue virus. We are keenly awaiting the results of the trial in India because it will help in prevention of the disease. Our focus is more on prevention than treatment as there is only supportive treatment for dengue.”
This year till June-end, there have been 3,763 dengue cases reported from all over the country, including two deaths recorded in Kerala. Last year, there were 167 deaths due to dengue.