HealthDay News — More children worldwide are being paralyzed by polio viruses from vaccines than from viruses in the wild, according to new data.
The World Health Organization and partners last week noted nine new vaccine-linked polio cases in Nigeria, Congo, Central African Republic, and Angola, the Associated Press reported.
Seven other African countries have similar outbreaks, and there have also been cases in Asia.
It is rare, but the live virus in oral polio vaccine can mutate into a form that can cause new cases. All the current vaccine-related cases have been caused by a type 2 virus in the vaccine. The wild version of the virus was eliminated years ago, the AP reported.