[Reactogenicity associated to the intradermally administered inactivated poliovirus vaccine with a needle-free injector].

Introduction: As the goal of poliomyelitis eradication is about to be accomplished, the need for an affordable and appropriate inactivated poliovirus vaccine (IPV) for use in developing countries has become a target for WHO.

Objective: To evaluate the reactogenicity of the inactivated poliovirus vaccine.

Method: An experimental-type multicenter study was conducted, as part of a Phase I-II controlled clinical randomized and blinded assay, in 471 healthy infants of both sexes born in July and August 2006 in Camagüey province. The parents of the children who met the inclusion criteria gave their consent in writing. The children received three doses of the inactivated poliovirus vaccine at 6, 10 and 14 weeks after birth. This vaccine came form the Institute of Sera in Denmark and had been approved for use in this assay by the Cuban regularoty authorities, Low 0.1 mL inactivated poliovirus vaccine dose was intradermally administered to the study group A in the anterolateral side of the left thigh using the needle-free injector called Biojector 2000. The usual 0.5 mL dose was intramuscularly administered on the same site using a pre-filled syringe. The adverse events were observed during the first hour, 24, 48, and 72 hours after the immunization, as well as 7 and 30 days afterwards. The pediatrician in charge of the health area evaluated the reactogenicity at first and then the family physician was in charge of observing the adverse events in the remaining period.

Results: The 79.6% of children in group A and 75% in group B completed the research protocol. Mild local adverse reactions prevailed, mainly induration, pain and redness at the injection site.

Conclusion: the Clinical trial proved the safety of the inactivated poliovirus vaccine for intramuscular administration, and also showed the safety of the intradermal route of administration and of the needle-free injector.