Clinical Surveillance After Feeding Oral Attenuated Live Polio Vaccine

During widespread administration of oral poliomyelitis vaccine in the United States and Canada, a number of neurological conditions occurring within 30 days of vaccine administration were reported. After careful investigation, 11 cases of paralytic poliomyelitis in the United States and four cases in Canada have been accepted as being most probably vaccine-associated.The case of a 35-year-old man who developed paralytic poliomyelitis 17 days after taking oral vaccine is reported. Type III Poliovirus was isolated from his stools, and subsequent virological investigation of this virus strain suggested that it most likely was the attenuated strain. The McBride test gave an NK value of 90 and the rct/40 marker was positive. A rise in Type III antibodies was found in the patient's serum, and increased neurovirulence was demonstrated by intracerebral inoculation of monkeys.Since many cases of neurological involvement have not been accepted as vaccine-associated because of the lack of adequate early investigations, active clinical surveillance after oral polio vaccine administration is urged, and appropriate studies should be carried out in suspect neurological complications.