Critics say that no sterilization system is perfect, farmed fish invariably escape and the impact of a genetically engineered salmon on wildstocks is unknown.
Laboratory stocks must be contained and safe management of the wild virus in inactivated polio vaccine (IPV) manufacturing sites must be assured before the world can be certified polio-free.
But the report laments that far too much of the harvesting of, and trade in, wild products is poorly supervised, with the result that habitats are degraded and stocks depleted.