Seroimmunity to polioviruses in an urban population of Italy.

In a seroepidemiological survey on immunity to polioviruses, carried out in Rome, neutralizing antibodies were titrated on 602 serum samples collected from individuals aged from 6 months to 88 years. The geometric mean titres were 25.24, 25.92, and 18.12 for poliovirus types 1, 2, and 3, respectively. The number of seronegative results for each virus strain was very low (</=1.5%). The immune status of the study population could therefore be considered satisfactory. The distribution of antibody reactivity in different age groups was similar for poliovirus types 1 and 3, while for type 2 a significant difference in titres was found between adults and children.