Trials of indigenous cholera vaccine successful so far

An indigenous cholera vaccine has been found safe and effective in the second stage clinical trial, prompting the scientists to plan for the last round of the trial on 1,000 people to firmly establish its potential.

Developed by researchers at the National Institute for Cholera and Enteric Diseases (NICED), Kolkata, the single dose oral vaccine has been found better than a Rs 400 two-dose vaccine, available in the market.

Cholera continues to be a public health threat in South East Asia including India, Africa and parts of the South America. It affects more than 100,000 Indians and kills 8000-10,000 every year primarily among the poor in West Bengal, Tamil Nadu, Maharashtra and Andhra Pradesh.

“The phase-II trial on 44 adults shows the vaccine is safe and effective and it can be taken forward for the phase-III trial,” G B Nair, former director of NICED, who led the vaccine development effort told Deccan Herald.

It would be effective against an emerging and more virulent strain of the cholera bug, said Nair, who currently heads the Translational Health Sciences and Technology Institute, here. When in use, the oral vaccine could be given to everybody above 12 months of age.

As per Indian drug regulatory requirement, every new drugs and vaccines have to undergo three phases of clinical trials to prove its safety and efficacy. The third phase would be the biggest, in which the drug or vaccine is tested on the largest number of people to check its efficacy. The entire process can take anything between 10-15 years.

“In the next step, NICED would test the vaccine’s safety on children before going ahead for phase-III in which some of the kids too will be given the vaccine,” said T Ramamurthy, a senior NICED scientist.

The indigenous vaccine has two distinct advantages over two other products currently available in the market. Swedish vaccine Duckoral is expensive and used primarily as the vaccine for travellers visiting cholera-endemic areas.

The second vaccine in the market is Shanchol – developed by Seoul-based International Vaccine Institute and manufactured by Shantha Biotechnics in Hyderabad – which would be difficult to administer in a public health campaign because if the recipient does not return after two weeks for the second dose, the vaccine (Shanchol) won’t protect much.

The department of biotechnology has begun talks with pharmaceutical companies in order to rope one of them in the phase-III.

In the phase-II trial – published in the journal PLOS One – 44 persons were given the vaccine whereas 43 individuals were in the control group. The NICED vaccine remains stable at least for 12 months.