Experience of vaccination with inactivated poliomyelitis vaccines in Iceland.

Iceland, as a few other European countries, has used inactivated vaccine against poliomyelitis from the beginning in 1956. No cases of paralytic polio occurred since 1960. For 17 years neither isolations of poliovirus nor suspected cases of the clinical disease have been recorded. Studies on neutralizing antibodies in sera of vaccinees were not too encouraging after 4 injections. A 5th vaccination of IPV was therefore given to those children who lacked antibodies to any type of poliovirus. One month after the 5th injection 70% had antibodies against all 3 types of poliovirus and only 2% lacked antibodies against both types 1 and 3. In countries where no virus to boost immunity exists any longer during the life of an individual it may be necessary to secure booster effects at regular intervals after primary vaccination and later in life. This will be included in the vaccination schedule against polio in Iceland.