Poliovirus Immunization with Fractional Doses of Inactivated Vaccine

Although much progress has been made toward eradicating poliomyelitis, pockets of polio infection requiring continued vaccination efforts still exist in resource-poor areas. To evaluate the use of fractional doses of inactivated poliovirus vaccine (IPV), researchers randomized 310 Cuban infants to receive either a standard (full) intramuscular dose of IPV or a fractional intradermal dose of IPV (one fifth the standard dose) at ages 4 and 8 months.

Seroconversion rates to poliovirus types after administration of the second dose of full or fractional IPV were >90% (see table).

Comment: Although responses to fractional doses of inactivated poliovirus vaccine were lower than responses to full doses, more than 90% of infants who received the reduc…