Scientists closer to developing indigenous vaccine for diarrhoea3 min read . Updated: 14 May 2013, 10:48 PM IST
if approved for commercial use, could save at least 60,000 children a year from diarrhoeal deaths
New Delhi: Scientists in India have come the closest ever to developing a wholly indigenous vaccine called Rotavac that, if approved for commercial use, could save at least 60,000 children a year from diarrhoeal deaths and will cost a tenth of the price at which the cheapest comparable vaccine is currently sold.
While by no means a first-of-its-kind vaccine for rotavirus infections, it marks the first time that the entire chain of vaccine development—from discovering a new strain of virus to steering it through so-called Phase 3, or advance trials, mandatory for proving the efficacy of a vaccine, has been successful in India.
Internationally, successful Phase 3 trials are a precursor for companies applying for regulatory approval to launch commercial drugs.
A consortium of scientists that included researchers from the All Indian Institute of Medical Sciences, the National Institute of Immunology, Society for Applied Studies, Bharat Biotech International Ltd, as well as American institutions said they had received encouraging results from Phase 3 trials of a molecule that was tested in at least 7,000 impoverished children in three Indian cities.
The Phase 3 trials suggested that “...Rotavac significantly reduced severe rotavirus diarrhoea by 56% during the first year of life, with protection continuing into the second year of life", according to a press statement by the consortium.
Rotavirus is a family of viruses that is responsible for some 453,000 child deaths due to diarrhoea globally and kills at least 100,000 in India. Though vaccines are available for preventing rotaviral infections and they have efficacy rates of over 80%, experts associated with this Indian vaccine say there is still a compelling case for yet another such vaccine in India.
The Global Enteric Multicenter Study (GEMS) that enrolled more than 20,000 children from seven sites across Asia (including India) and Africa, said in study published in Lancet on Monday that rotavirus was the leading cause of diarrhoeal diseases among infants under 11 months across all sites and identified other top causes for which additional research is urgently needed. GEMS evaluated nearly 40 pathogens to map each one’s relative contribution to diarrhoeal disease. Combining data from all seven study countries, GEMS found that one in five children under the age of two suffers from so-called Multiple Skeletal Disorders each year, which increased children’s risk of death 8.5 times and led to stunted growth over a two-month follow-up period.
Currently, two vaccines are available for rotavirus infections: GlaxoSmithKline Pharmaceuticals Ltd’s Rotarix and Merck’s RotaTeq. Rotarix is priced at ₹ 2,398 for the complete course that comprises two doses and RotaTeq is a three-dose vaccine that costs ₹ 1,200. The new version that has been tested in India will cost $1 (around ₹ 55) a dose.
All rotavirus vaccines that are commercially sold, as well as the proposed Rotavac, were equally effective, said M.K. Bhan, former secretary of the department of biotechnology and among the discoverers of the rotavirus strains that is employed in Rotovac. However, better healthcare and nutrition available in developed countries means that the vaccine appeared more efficient there than in the developing countries, he added. “That’s why rotavirus vaccines in the West have an efficacy of around 80%," said Bhan, “were Rotavac administered in similar settings it would show similar numbers (around 80%) than the 60% and 56% we’ve obtained in our clinical trials among poor colonies in India." Given that the risk of secondary infections are the same, the extremely low cost of this vaccine means that it is absolutely essential for India’s health programme, Bhan added.
However, a major side effect of rotavirus vaccines, bowel constriction, hasn’t been entirely detailed in the case of the indigenous Rotavac and will be known only in subsequent stages of monitoring, Bhan said.
Krishna Ella, managing director of Hyderabad-based Bharat Biotech, said his company would be approaching the Drug Controller General of India in July for approval to produce the vaccine. It would take at least a year for commercialization of the product, he said. “We’ve invested about ₹ 60 crore in this project," said Ella, “and hopefully Rotavac will be popular not only in India but in several developing countries that face problems with diarrhoeal infections."
Independent experts said that 60% efficacy was a promising enough result to go ahead with developing a vaccine, provided there were no additional side effects. “It’s an encouraging number," said T.S. Balganesh, who leads a CSIR (Council of Scientific and Industrial Research) effort to develop new drugs for tuberculosis, “but that has to be seen in the light of the costs, side effects, ease of administering the vaccine etc. I’d wait for the research publication to be sure of all of these."