This week, researchers began a coordinated worldwide effort to switch over to a new polio vaccine, and destroy all remaining stores of the old version in the process.
"This changeover is unprecedented," Walter A. Orenstein, MD, associate director of the Atlanta-based Emory University School of Medicine's vaccine center, told The New York Times.
Only 74 cases of polio were reported in 2015, and all were limited to Pakistan and Afghanistan. This is considered a huge win for vaccine science considering at its peak in 1952, more than 21,000 children were infected in the U.S. alone. The new vaccine only targets two strains, leaving out a third that the prior formulation fought off but was eradicated in the late 1990s.
The Global Polio Eradication Initiative aims to have the switchover completed by May 1. The process includes disposing of old vaccines and the deployment and storage of hundreds of millions of doses of the new version.