India was taken off a list of polio endemic countries by the World Health Organisation on Saturday, marking a massive victory for health workers battling the crippling disease.
"This gives us hope that we can finally eradicate polio not only from India but from the face of the earth," Prime Minister Manmohan Singh said.
The announcement leaves just three countries with endemic polio -- Pakistan, Afghanistan and Nigeria.
India, which last reported a fresh polio case more than 12 months ago, now will have to remain polio free for the next two years to be judged to have eradicated the disease, WHO representative in India Natela Menabde said.
"The government of India has coordinated a massive effort to rid our country of the terrible scourge of polio that has scarred the lives of thousands of thousand of children in India," Singh told a polio summit in New Delhi.
But "the real credit" for India's success in tackling polio goes to the volunteers who repeatedly vaccinated children, he said.
They visited slums and railway stations, construction sites and bus stops, using all means of transport to reach even the most far-flung corners of one of the world's most crowded and impoverished countries.
The success of the effort shows that "team work pays," Singh said.
Health Minister Ghulam Nabi Azad said he received a letter stating that the "WHO has taken India's name off the list of polio endemic countries in view of the remarkable progress that we have made during the past one year."
Polio -- which afflicts mainly the under-fives causing death, paralysis and crippled limbs -- travels easily across borders and is transmitted via the fecal matter of victims.
India has been a frequent exporter to other developing countries, but has also been re-infected from abroad. The ancient disease was wiped out from the 1970s in developed countries through successful vaccination campaigns.
In 2009, India accounted for half of all cases in the world, but infections plummeted to 42 in 2010 and none in the last 12 months.
The Indian government has spent $2 billion over the last 10-15 years on polio eradication efforts.