Magic drop

scientists from the Dhaka-based International Centre for Diarrhoeal Disease Research (icddr,b) have recently initiated clinical trials to study the efficacy of an oral diarrhoea vaccine in Bangladesh. The vaccine is being manufactured by the international pharmaceutical giant GlaxoSmithKline. It has been developed by Baltimore-based John Hopkins University.

The vaccine would prove to be better than the ones available at present as it has been derived from the virus affecting humans rather than from virus affecting animals. It is also being tested in South Africa, Finland, Peru and the us. The trials in Bangladesh, being carried out at the Dhaka Shishu Hospital in collaboration with the World Health Organisation, will be conducted over the next two years. If they prove successful, the vaccine would be very useful for the country where diarrhoea kills around 20,000 children each year. " These trials would also help other developing countries,' says David Sack, director of icddr,b.

The vaccine consists of a single strain of a rotavirus, which causes the disease. To make the vaccine, the virus is weakened so that it is unable to cause the disease but brings about immunity against the virus. When earlier tested on infants at the us-based Cincinnati Children's Hospital Medical Centre, the researchers found that out of the 108 children who received two doses of the vaccine, only two contracted the disease. On the other hand, 18 out of 107 children who did not receive the vaccine got the disease. Expressed mathematically, the efficacy of the vaccine was found to be 89 per cent.

However, the vaccine has some mild side effects such as fever, vomiting and immediate occurrence of diarrhoea. There is also a chance that the weakened virus might revert to its infectious form. On the positive side, the vaccine can be easily administered as it is given orally and it might prove to be cost-effective.