"Oral polio vaccine (OPV) contains an attenuated (weakened) vaccine-virus, activating an immune response in the body. When a child is immunized with OPV, the weakened vaccine-virus replicates in the intestine for a limited period, thereby developing immunity by building up antibodies."- (It is not quick immune response) style="font-size: 1.04761904761905em; font-family: Times New Roman, Times, serif">en/index.htmlOPV is a live attenuated vaccine.:"The oral polio vaccine (OPV) was developed in 1961 by Albert Sabin. Also called "trivalent oral polio vaccine" or "Sabin vaccine". OPV consists of a mixture of live, attenuated (weakened) poliovirus strains of all three poliovirus types."- style="font-size: 1.04761904761905em; font-weight: bold; font-family: Times New Roman, Times, serif; margin: 0 0 0 8px; text-indent: 0">OPV is used in epidemic:"As IPV does not stop transmission of the virus, oral polio vaccine is used wherever a polio outbreak (epidemic) needs to be contained, even in countries which rely exclusively on IPV for their routine immunization programme (e.g. the polio outbreak in the Netherlands in 1992)."- style="font-size: 1.04761904761905em; font-family: Times New Roman, Times, serif"> InactivatedpoliovaccinelPV.aspxMaternal antibody interferes with immune response:"Live OPV virus stimulates antibody formation by inducing a mild infection in the gastrointestinal tract and the blood of immunized children. The presence of circulating maternal antibodies may modify the infection created by the attenuated vaccine virus and reduce both the serum and gut response to OPV immunization. While circulating maternal antibodies may suppress the infant's serum antibody response, only very high maternal antibody titers can prevent the intestinal phase of successful poliomyelitis immunization. Even those children who do not develop serum antibodies maybe protected if they have had the vaccine intestinal infection."-">