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.
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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.
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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