‘The switch’ was supposed to be a major step toward eradicating polio. Now it’s a quandary
Three years ago, the leaders of the international campaign to eradicate polio pulled off a landmark feat, phasing out a problematic component of the vaccine used in developing countries, and introducing a newer version that they hoped would put the world on a better footing to finally eliminate a global scourge.
Now, some organizers are weighing whether “the switch,” as the process was known, needs to be reversed.
