“…And the major part of the OPV used for vaccination in Iran has been provided by the local manufacturer which used MRC-5 cells for vaccine production. Exhaustive national surveillance of all acute flaccid paralysis (AFP) cases in Iran, especially in recent years, revealed that only a few cases (six cases during 10-years of surveillance) had VAPP, mostly in association with immunodeficiency (iVAPP), have been reported as yet [Parvaneh et al, 2007;Rahimi et al, 2007a,b;Davarpanah et al, 2008;Mamishi et al, 2008;Shahmahmoodi et al, 2008Shahmahmoodi et al, , 2009, and no increased level of complications was observed in vaccinees. The risk of VAPP among recipients and/or contacts was 1 case per 745,000 to 7,142,000 used doses of OPV in different parts of the world [WHO, 1982;Nkowane et al, 1987;Joce et al, 1992;Strebel et al, 1992;Prevots et al, 1994;Andrus et al, 1995;Kohler et al, 1999;Zimmerman and Spann, 1999;SamoDlovich et al, 2007].…”