'The number of households overtly refusing oral polio vaccine is the lowest ever, and the resistance is now more sporadic and significantly less,' the minister said.

'In May 2009, less than 0.1 percent of the 3.3 crore households in Uttar Pradesh and less than 0.1 percent of the 1.59 crore households in Bihar refused vaccination,' he added.

Refusal by families to allow their children to be given the vaccine in parts of Bihar and Uttar Pradesh was blamed partially for the large number of cases in this part of country. Some people harbour a prejudice that polio drops can lead to impotency in children during adulthood.

India is one of the few countries that is still reporting polio cases in the world.