CVDPV still is weaker than "wild" polio - only about 1000 cases ever (out of billions of vaccinations), and outbreaks are controlled quickly (if slower than the

CVDPV still is weaker than "wild" polio - only about 1000 cases ever (out of billions of vaccinations), and outbreaks are controlled quickly (if slower than the original expectation). Apparently both due to remaining mutations and since it's nearly all polio type 2 - which was otherwise eradicated a long time ago, apparently that type is a bit less "fit". It's a problem, but one that can be managed by the existing tools which brought polio down to this level - many countries switched from trivalent OPV or removed OPV2 precisely to avoid this scenario, and a new OPV2 vaccine will hopefully eliminate the problem in the affected areas: http://polioeradication.org/wp-content/uploads/2020/07/cVDPV2-nOPV2-fact-sheet-July-2020.pdf http://polioeradication.org/wp-content/uploads/2020/07/cVDPV...