Polio has almost been eliminated in the world. Africa reported no new cases of polio in 2014 for the first time ever. Javier Martin from the National Institute for Biological Standards and Control in Potters Bar in the United Kingdom and colleagues have found a mutation produced by one type of polio vaccine that may cause the disease to linger on or even mutate into a different crippling form.
Polio is prevented with two different types of vaccines. Inactivated polio vaccine uses inactive virus to produce antibodies to the disease. Inactivated polio vaccine does not prevent the growth of live polio virus in the mucosal lining of the intestines. Oral polio vaccine contains weakened live virus and does prevent the excretion of live virus from the digestive tract. Oral polio vaccine can produce unexpected vaccine-induced polio and the use of the oral vaccine has been discontinued.
The researchers found one person n Britain that has been excreting live polio virus into the sewage system of Britain for 28 years. They also found people in Slovakia, Finland, Estonia, and Israel that produced live polio vaccine in their feces. The polio that is excreted is not virulent at present. The production of the new polio variant is the result of immunodeficiency. The researchers expect that a new vaccine may have to be developed to cope with the excreted polio virus in sewage because the virus could mutate into a virulent form in sewage.
