of DPT, OPV, and Haemophilus influenzae type b (Hib) vaccine and a combination of DPT, OPV, measles-mumps-rubella vaccine (MMR), and Hib vaccine, but the temporal and clinical details are insufficient for proper evaluation. Another VAERS report of transverse myelitis was a duplicate of the case report published in 1990 and discussed above (the 24-year-old woman). In addition, at a public meeting held in January 1993, the committee heard about a 4-month-old girl who developed transverse myelitis, diagnosed by neurologists, a few days after her second DPT and OPV immunizations. This was thought by the physicians treating the girl to be related to her immunizations (see Appendix B).

None.

None.

There is biologic plausibility that viral vaccines can cause demyelinating disorders. Vaccine-strain poliovirus can enter the central nervous system and has been associated with a peripheral nerve demyelinating disorder, Guillain-Barré syndrome (see next section). The three cases of transverse myelitis following receipt of OPV reported in the literature, the two cases reported in VAERS, and the case identified by the committee in a personal communication are inadequate to indicate an association between OPV and transverse myelitis beyond that due to chance alone. At least five of the cases occurred following multiple immunizations, which complicates an assessment of a causal relation between OPV and transverse myelitis. No cases of transverse myelitis following receipt of IPV have been reported.