Paralytic poliomyelitis in England and Wales 1976-7

In 1976-7 26 cases of paralytic poliomyelitis were notified, of which 6 were vaccine-associated. 16 of the 20 non-vaccine-associated cases were due to type-u poliovirus, the type usually associated with outbreaks. The most important factor in the increase was the occurrence of poliomyelitis in unvaccinated persons.