The actor said that there had been far fewer polio cases this year than when he first became a UNICEF ambassador.
"Feel proud and delighted that finally our efforts have been successful. Started in 2002, with over 1000 cases and today just one in West Bengal," he wrote on Twitter.
"This year's Polio Campaign… no case reported from Uttar Pradesh and Bihar, which are most vulnerable states. Only one case in West Bengal!" he added.
The actor attended an event in Mumbai where he launched a new UNICEF campaign for polio, and was honoured by the government and UN officials for his work towards polio eradication.
"UN officials tell me that hopefully by early next year we shall be able to announce that India is finally free of polio," he continued. "I am so delighted that the polio eradication campaign and my incessant plea of 'do boond zindagi ke' has proved so successful!!
"But let's not sit back, let's keep at it to completely free our country of this dreaded disease… each Indian owes this to the nation."
The veteran star also thanked other celebrities who were involved in the campaign, and gave a word of advice to all parents.
"May I also add here that polio is incurable, but it can be prevented provided the vaccine is taken in time," he said. "And yes, on some of the campaign videos I did invite Sachin (Tendulkar), Aishwarya, SRK (Shah Rukh Khan), and Jaya (Bachchan) to promote the cause… so thank you to all!!"