Polio Could Be Eradicated Within One Year

We might be on the verge of completely eliminating one of the world's most devastating diseases: polio.

The prehistoric virus might soon join smallpox—which was eradicated in 1980—to become the second infectious condition humanity has ever officially put a stop to. According to the World Health Organization (WHO), we could see the disease gone by as early as a year from now.

This year, Pakistan and Afghanistan are the only countries to have experienced cases of wild (as opposed to vaccine-derived) polio. They only saw two and seven cases each, bringing the world total to a puny nine.

The WHO estimates that even if cases do increase in the summer months, the disease, which was once responsible for paralyzing thousands of children, could no longer harm anyone.

"We absolutely need to keep the pressure up, but we think we could reach the point where we have truly interrupted the transmission at the end of the year or the end of the low season [winter] next year," Michel Zaffran, the WHO's director of polio eradication told The Guardian.

The disease, which is spread through human contact, primarily affects areas plagued by poor sanitation. The WHO is concentrating its efforts in areas where the virus is known to still be a problem, including the Pakistani capital of Karachi, and two other areas in the country.

In Afghanistan, 47 districts have been prioritized for vaccination and monitorization. One of the challenges facing health workers is that 32 of them are under the control of anti-government forces, according to the WHO. Political conflicts in the region have previously interfered with vaccination efforts.

The downturn in polio cases can largely be credited to the global polio eradication initiative, which since 1988 has reportedly administered vaccines to over 2.5 billion children. The oral vaccine, which is the most frequently administered, can cost as low as 10 cents a dose.

The injectable version of the vaccine is safer in some regards, because it contains an inactivated version of the virus that's incapable of mutating back to an infectious state. An Indian pharmaceutical billionaire began selling the injectable version at a loss in 2013, and the CDC says a switch to this form of protection will take place in the future, once there are no longer wild cases of the disease reported.

In the meantime, between April 17 and May 1, 150 countries will switch from one oral vaccine to another. The original vaccine, the trivalent oral poliovirus vaccine (tOPV) protects against three types of polio, whereas the new vaccine, bivalent oral poliovirus vaccine (bOPV) only protects against two.

The switch is being made because one kind of polio, wild poliovirus type 2, hasn't been reported since 1998. In extremely rare circumstances, generally when a population is not adequately vaccinated, the live virus in the oral vaccine can sometimes mutate and infect people.

In 90 percent of the cases where people were infected, wild poliovirus type 2 was responsible for the outbreak, so the global polio eradication initiative decided to remove it.

According to the WHO, in 1988 there were an estimated 350,000 cases, and by 2014 there were only 359 reported instances of the disease. If polio is eliminated, it will be a tremendous victory for vaccination advocates, and clear evidence that coordinated international public health efforts can have dramatic and encouraging effects.