Madagascar reports 9th circulating vaccine-derived poliovirus type 1 case of 2015

What are Vaccine-derived polioviruses (VDPVs)? The Global Polio Eradication Initiative defines it as follows: The oral polio vaccine contains a live, attenuated (weakened) vaccine-virus. When a child is vaccinated, the weakened vaccine-virus replicates in the intestine and enters into the bloodstream, triggering a protective immune response in the child. Like wild poliovirus, the child excretes the ["]