Polio immunization policy in the United States: a new challenge for a new generation.

The primary reason that live poliovirus vaccine is recommended in the United States today is because it may immunize contacts who have not otherwise chosen to be vaccinated. This policy places contacts at risk of paralysis from an untested, unlicensed "spread virus" vaccine and places infants at risk for an unproven, theoretical benefit to others, not themselves. The licensed killed poliovirus vaccine provides equivalent protection to those vaccinated, with no risk to recipients or contacts. The preceding analysis by Hinman, et al, is an interesting exercise in modeling, but many of their assumptions are open to question. Their sweeping conclusions are not justified by the type of analysis performed, which should yield an overall assessment of a decision environment not a single optimal choice. No measure of perceived social consequence or patient attitude is included, although this is of central importance today. Their report lends an aura of credibility to one conclusion, but this credibility is illusory at best. The major social issue today is not which vaccine to use, but how should polio immunization policy be evaluated.