In January 1988, a prestigious panel appointed by the Institute of Medicine (IOM) reviewed policy options for vaccination against poliomyelitis.1 The IOM last reviewed this subject in 1977, at which time it concluded that live, trivalent oral poliovirus vaccine (OPV) was the preferred vaccine but recommended killed, inactivated poliovirus vaccine (IPV) for immunodeficient people and those with immunodeficient family contacts.
The new IOM review was prompted in part by licensing of an enhanced potency inactivated polio vaccine (E-IPV). This vaccine, produced in human diploid cells, has a higher an tigenic content than does conventional IPV and, therefore, children can be satisfactorily immunized with fewer doses.2 A combined diphtheria and tetanus toxoids and pertussis vaccine (DTP)-E-IPV will likely become avail able within 2 to 5 years.
Other developments prompting the IOM review included the following: (1) the probable interruption of transmis