Evaluation of oral poliovirus vaccine delivery during the 1994 national immunization days in Pakistan.

Pakistan conducted national immunization days (NIDs) for the first time in 1994. To estimate coverage, to evaluate risk factors for failure to be immunized, and to determine the effectiveness of mass media, parents of 1288 children in 714 households in four districts were surveyed after the first NID round. In each district, a high proportion of children (93%-96%) received oral poliovirus vaccine (OPV) during the NID.