Sunday, November 23, 2008

Polio Eradication

Because I had polio at age 5, the hoped-for eradication of the disease is something I keep up with. Most efforts heretofore have used a so-called "trivalent" oral vaccine that is intended to simultaneously immunize against Type 1, Type 2 and Type 3 versions of polio. Type 2 polio is believed to be already extinct worldwide. Recently, monovalent vaccines against Type 1 and Type 3 have been separately certified. This is important because in endemic areas of the world such as India and Nigeria, the virus is so prevalent that the oral immunizations against multiple types compete with each other in binding to the gut. Therefore the monovalent versions are believed to be and mostly have been proven to be more potent. Sometimes the trivalent version is still used when both Type 1 and Type 3 are still present. Those are now alternated with the monovalent versions in various campaigns.

The success of the most recent campaigns has been mixed. The geographic diversity has been reduced to fewer countries, but, the absolute number of infected people has increased. The reason for this is mostly because of Islamic distrust of the rest of the world. They believe that medical personnel are trying to sterilize them and some imams vigorously campaign against it. Some medical people in Pakistan have been killed. Of course, Islamic doctors campaign in favor of immunizations. Northern India, Pakistan, and Afghanistan are now the major reservoirs in Asia with mostly Nigeria infecting the rest of Africa sporatically.

No one knows how all this will turn out. In Nigeria, it is the corruption of officials hoping for a bribe that holds up things combined with religious fervor doing likewise. In Asia, it is mostly religion.

It is not obvious how much longer the world will continue to fund the eradication effort. If things collapse, infection will spread again worldwide. So far, there is still hope that the monovalent potency will reinvigorate the campaign. Asia has mostly type 3 and a bit of Type 1 combined, whereas in Africa it is the opposite. I hope everyone will contribute to the effort. The worldwide economic collapse is not helping things. There is still hope. Saudia Arabia holds a trump card. They do not allow haj unless a person is accompanied by a polio immunization certificate.

No comments: