India has ended a long and expensive fight against polio and now the World Health Organization (WHO) has declared the country free of the crippling disease.

According to BBC News, India has gone three years without a new case of polio, meaning it is considered to be eradicated. WHO now says 80 percent of the world is polio-free.

WHO is aiming to finish the fight against polio by 2018 and the disease is still endemic in Afghanistan, Nigeria and Pakistan. Syria, a country that had previously ridded itself of polio, recently experienced an outbreak.

Southeast Asia now joins the Americas, Western Pacific and Europe as four of six total WHO regions to be declared polio free. India's fight against polio spanned two decades and cost billions of dollars, making the victory one of the most satisfying in world health history.

India began an aggressive vaccination campaign focusing on children, since that is who the disease mainly affects. One in every 200 people infected with polio can also face paralysis from the disease.

"This is very significant because before this region was certified polio-free, we had half the world's population polio free," Dr. Poonam Khetrapal Singh, WHO South East Asia regional director, told BBC News. "With the South East Asia region being added we now have 80% of the population polio free.

"This was a problem the region was struggling with for a long time, but now finally, we are polio free."

The Global Polio Eradication Initiative was started in 1988, Reuters reported. WHO, Rotary International and the U.N. Children's Fund were among the globe's leaders in ensuring its mission. When it began, at least 350,000 children in 125 countries were dying or becoming paralyzed from polio sickness.

In 2013, that number has plummeted to just 406 cases, representing a 99.9 percent drop. Now, the world will focus its energy on that last 0.1 percent.