This is the fifth year of mass vaccinations in Pakistan, and, despite the scale of the task involving over 160,000 vaccination centres across the country, it's been a remarkable success.

In 1993, there were 1,800. After two years of vaccinations, the number of cases went down to 36. United Nations health officials say Pakistan should be able to eradicate polio by the year 2000.

'Polio' is short for poliomyilitis, a highly infectious virus which attacks the brain and spinal cord and can cause paralysis and muscle wastage.

The cost of the vaccination programme is small - about $10 million a year. The challenge for the government has been to mobilise the number of health workers needed to reach the population at risk.

There's been a campaign on national television and radio, and school days have been organised around the vaccination programme.

This is the one health issue where Pakistan can be proud of its achievements. Otherwise, the country has had a poor health record.

The reason is the spending priorities of the politicians. Half the budget goes on paying off Pakistan's massive debt, and half of the rest on defence; there's little left over for social development.

About half the population does not have access to health facilities or clean water and there are over 300,000 people estimated to die every year from easily preventable diseases.