1 Department of Pediatrics and Microbiology, State University of New York Upstate Medical Center
A partially immunized recreational school population in central New York has been studied during the course of an outbreak of poliovirus Type I infection. The data indicate that some increased resistance to poliovirus Type I infection occurred following immunization but that the effect was limited to extra-household contact and was not apparent within households where infection occurred regardless of the immunization status of either the presumptive source or contact.
Relatively poor antigenicity of the vaccine used seems the best explanation for the lack of demonstrable effect on prevalence of pharyngeal polioviruses among infected persons. The present study emphasizes the need for universal immunization if clinical poliomyelitis is to be effectively controlled with Salk-type poliomyelitis vaccine, and it further provides a base-line for studies with attenuated polioviruses in this population.