Polio Vaccinations - The end of a scourge?

It was only a few decades ago that Jonas Salk's research led to the use of the deactivated polio virus to inoculate and immunize children. It was a medical breakthrough, but Western leaders were suspicious of the vaccine's safety. So the first large scale vaccinations took place in Cuba, where Fidel Castro welcomed the vaccine.

Since then, the polio vaccination effort has progressed in fits and spurts. In the 1960's researchers discovered SV40 contamination of the vaccination, that elicited more fear. But over time the effort steadily gained popularity and trust. In 1988 the World Health Assembly led a worldwide program to eradicate the disease that for the most worked. In 2003, the World Health Organization (WHO) reported fewer than 700 cases worldwide, down from 350,000 in 1988.

Yet the history of polio has shown that infectious disease eradication is challenging even with an effective vaccination. The majority of polio cases occur in remote regions of the world,where people have little access to running water, sanitation, food, or basic health provisions. Poorer countries are challenged trying to distributed vaccines because of lack of refrigeration. Ice packs chill the vaccines effectively, but need to be refrozen and in many rural areas where basic amenities like electricity are scarce. Transportation to distribute the vaccines is also difficult in remote terrain. Communication also proves challenging. Accurate records of vaccinations need to be maintained and villages need to be notified of upcoming vaccinations and convinced that the medicine is safe for their children.

Despite these challenges, the World Health Organization (WHO) reports that from 1998 to 2003, "the world's largest public health campaign" the Global Polio Eradication Initiative spanned 200 countries and employed 20 million volunteers, costing $3 billion dollars. When WHO wrote the report, they were confident the effort would pay off since only six countries remained polio-endemic: Nigeria, India, Pakistan, Niger, Afghanistan and Egypt. Doctors predicted that polio would be successfully eradicated by December 2005 (a postponement from 2002, which was a postponement from 2000). But today polio has re-emerged in eleven countries. In four of these countries outbreaks were imported virus due to migration or travel. Yemen reported 179 new cases and Indonesia 2 new cases in the past week.

The new outbreak is being traced to Africa where several countries blocked vaccination programs in 2003-2004. Officials in Nigeria for instance, began to suspect polio vaccines were a plot of Western countries against the fertility of Muslim girls and halted their vaccination campaign. In Mali 11 officials were jailed for not allowing citizens to be immunized or religious reasons.

The latest initiative was to be the last push of the campaign before the deadline. The good news is still that the number of cases worldwide is small. But at this stage of the campaign, the cost to treat each subsequent case increases significantly. And, as the recent outbreaks show, successful eradication could only be accomplished with constant vigilance. In India, where polio is indigent, 24 million or so births per year require that many new vaccinations. Adding to the difficulty, India's resources allow less than $4 per person to be spent on health care -- other African countries can spend half that much.

The high costs of the current effort invites cost benefit analysis by health economists and public health officials, who estimate that as many as 5 million cases have been prevented, however; the remaining cases could cost as much as $600/case. Some argue that the money to treat these remaining cases could be spent on basics like electricity or sewers (sewage is often the source of the virus).

Sometimes eradication via vaccination seems elusive, always 6 months out of reach. But ridding the world of polio -- crippling scourge of a virus that it is, will always be worthwhile goal.

follow us on twitter!