More than six decades on, it is hard to imagine the joy and relief that greeted news of the polio vaccine. In the US, church bells sounded, children were let out of school early and people embraced in the street at the prospect of vanquishing a virus that can cause paralysis, sometimes fatally.
The subsequent campaign against the virus has come remarkably close to eradicating it, in one of the great global health success stories. As recently as 30 years ago, 350,000 children a year were paralysed. Now, two of the three wild polio strains have been eradicated, and two years ago Africa was declared free of wild polio.
