Monday marked the third year since a case of polio was reported in India, a milestone that will pave the way for a World Health Organization certification officially recognizing the defeat of the disease in the subcontinent and the region as a whole, where it had long been a stronghold for the crippling malady.

A large-scale polio vaccination effort involving more than 2 million people combing throughout the nation's cites, slums and backwaters to inoculate the masses is at the center of the disease's downfall in the country of 1.2 billion people. The vaccination program is considered one of India's greatest public health success stories.

Ghulam Nabi Azad, India's Health Minister, called Monday's three-year anniversary a "monumental milestone" that marked the success of something once thought impossible in a nation that accounted for half of all the world's polio cases as recently as 2009.

"We have completed a full three years without a single polio case and I'm sure that in the future there won't be any polio cases," Azad said at a press conference, the AFP reported.

The World Health Organization (WHO) contends that a single country cannot be certified polio-free, but rather regions as a whole are certified as polio-free. By marking its third year without a case of polio, India paves the way for the entire Southeast Asia region to certified as free of polio by the WHO. After 12 months the WHO recognizes the absence of polio in a nation, but polio is considered eradicated only after three years pass without new infections.

"Historically, India has been the largest endemic reservoir of polio in the world with between 50,000 to 100,000 paralytic polio cases occurring each year between 1978 and 1995. It has also been one of the main sources of polio importation for other countries," the WHO said in a statement. "Three years of being polio free is a notable milestone for the country as a whole, but the success of the immunization and awareness campaign has had a wider impact - with this achievement, it is hoped that soon the entire Southeast Asia region can be considered certifiably free from polio."

WHO officials will convene in March to officially determine the polio status for the Southeast Asia region.

The last known case of polio in India was reported Jan. 13, 2011, when Rukshar Khatoon, an 18-month-old girl living in a Kolkata slum, was found with the disease, according to the AFP.

The girl now attends school and is living a "normal life," although she is still hampered by the effects of polio.

"She can now stand on her feet and walk, but can't run," her father Abdul Saha told the APF. "When her friends play, she remains a spectator." Saha, a father of four, told the AFP that it was a "grave mistake" when he took his son to get immunized, but not two of his daughters.