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.
The goal of the switch was to remove from circulation the part of the vaccine that protected against type 2 polioviruses, which were declared eradicated in 2015. The oral vaccine contains live but weakened polioviruses, which can on occasion paralyze children.
Thorough planning on how to do it safely was undertaken and, in most of the world, the switch was a success. But not so in parts of Africa, where three years later, type 2 vaccine viruses are being found over a widening swath of territory.
Many experts are banking on a new oral vaccine that all hope may solve the growing problem. If all goes well, the polio program may be able to start using it in mid-2020.
Read full, original post: ‘The switch’ was supposed to be a major step toward eradicating polio. Now it’s a quandary