NextBillion - An Initiative of the William Davidson Institute at the University of Michigan

Tuesday, April 19, 2016

The world is closer than ever to eradicating polio, the horrible disease that inflicts paralysis on its primarily young victims. It’s not far-fetched to say that very soon the world will see its last polio case.

But the tail end of the eradication efforts has been threatened by the very thing that made eradication programs a success: the vaccines themselves, which — in rare instances — can cause small outbreaks.

To combat that risk, starting this week 155 countries are switching over to a slightly safer form of the oral polio vaccine. The new vaccine is a lot like the current one, except that it will no longer immunize against one type of polio (Type 2), which was declared eradicated in 2015. In the next two weeks, the old vaccine will be discontinued completely.

“This represents the largest withdrawal of one vaccine, and associated roll out of another vaccine in history,” the Polio Eradication Initiative reports. International health agencies procure billions of doses of the oral vaccine every year.