As recently as the 1950s, polio was a dreaded, incurable disease that killed or paralyzed millions of children each year. The U.S. alone had 58,000 cases in 1952. Then came the invention of a vaccine by Jonas Salk, one of the great medical breakthroughs of the 20th century. By the 1960s, widespread vaccination campaigns had virtually eliminated polio from Europe and the U.S. Polio lingered in the U.S., mainly in the Amish population who refused to accept vaccinations, but it finally disappeared in 1979.
The worldwide campaign to eliminate polio started in 1988, when 350,000 infections were recorded. Polio is extremely difficult to control, because a large majority of infected people show no symptoms, but they can still spread the virus. Vaccination campaigns need to treat everyone who comes in contact with an infected individual in order to break the cycle of transmission. This is especially hard to do in remote areas of poor countries, especially when the populace is suspicious and uncooperative.
The greatest challenge in India came in the desperately poor, crowded regions of the north, where health care, hygiene, and education are all very poor. The vaccination efforts were made even more difficult by conspiracy theories among the Muslim population. As Simon Denyer wrote in the Washington Post this week:
"Rumors spread among the region's numerous Muslims that the polio vaccination campaign was an American conspiracy to wipe them out, by making their sons impotent and their daughters infertile.... Vaccinators were stoned as they approached Muslim neighborhoods. 'The general mind-set was that the immunization campaign was aimed at ending our lineage,' said Anwar Ahmad, the head of a madrassa in a Muslim neighborhood in the city of Meerut."The campaign turned around after UNICEF and Rotary international launched a major education effort that first convinced Muslim leaders, and then everyone else, that the vaccine would benefit their communities. With this success in India, polio is now endemic in only three countries in the world: Afghanistan, Pakistan, and Nigeria. The same rumors and conspiracy theories that plagued India have spread within Muslim populations in these countries as well, but India shows that the misinformation - and polio - can be defeated.
Unfortunately, even here in the U.S. we have our own conspiracy theorists: the anti-vaccination zealots over at Age of Autism, where Dan Olmsted and Mark Blaxill recently posted a series of articles claiming that polio is "a harmless intestinal bug" that only causes disease when triggered by pesticides or by arsenic. Never mind that there is no evidence to back this truly wacky assertion; these two anti-vaxxers seem happy to invent facts to support their single-minded campaign against all vaccines, even when the vaccines are demonstrably saving tens of thousands of lives.
Polio is still with us, and it could return. Besides the 3 countries with endemic polio, 9 other countries continue to suffer polio cases that were imported from endemic countries. Without widespread vaccination in those countries, polio could re-establish itself in any of them.
If polio stays out of India, we can thank the thousands of health care workers who traveled to remote villages, in extremely difficult conditions, to dispense lifesaving vaccines. Their heroic efforts have paid off for everyone. We should also thank the combined efforts of the WHO, UNICEF, Rotary International, the Gates Foundation, and the CDC, all of whom are backing the worldwide effort to eradicate polio. Let's root for humanity to win this one.