Parental knowledge and choice regarding live and inactivated poliovirus vaccines

Background: Concern about the 8 to 10 cases per year of vaccine- associated paralytic poliomyelitis caused by the live oral poliovirus vaccine (OPV) has led to revised guidelines for immunization of children in the United States. The use of inactivated poliovirus vaccine (IPV) at 2 and 4 months of age could require administration of 3 injections per visit until combination products are available. Objective: To determine parents' knowledge of poliovirus vaccines and the choices they would make between IPV and OPV. Methods: Parents of 240 children aged 2 weeks to 18 months under the care of 10 private pediatricians in the Baltimore, Md, metropolitan area were interviewed prior to the announcement of revised advisory committee guidelines. Results: The majority (62.5%) of respondents were not aware that 2 poliovirus vaccines are available. After reviewing standardized information about the vaccines and 2 alternate schedules, most (75%) parents would consult someone (primarily their physician) before making a final choice of a vaccine schedule. If parents made the choice without consulting anyone else, 61.3% would choose to have their child receive IPV and 3 injections per visit as compared with an all-OPV schedule and 2 injections per visit. Inactivated poliovirus vaccine was preferred by most parents because it would reduce the risk for vaccine-associated paralytic poliomyelitis. Oral poliovirus vaccine was preferred by 37.9% of parents primarily because it was given orally. If the number of injections at each visit was the same for both vaccines, 76.3% of parents would choose the IPV schedule, and if the number of injections was reduced to 2 by combining IPV with another vaccine, 87.9% of parents would choose IPV. Conclusion: The number of injections per visit is an important issue, but a majority of parents would choose to have their children receive extra injections to prevent the low risk for vaccine-associated paralytic poliomyelitis.