Abstract

Inactivated poliomyelitis vaccine, produced by the RIVM, has been evaluated for its immunogenic potential in humans in several countries in different vaccine compositions and in various vaccination regimes. A vaccine containing 40-8-32 DU/dose of poliovirus types, 1, 2 and 3 respectively, is considered suitable for use in humans. The vaccine is 90-100% effective after one dose given to 6-months-old infants and after 2 doses given to 2-months-old infants, when circulating antibodies are used as criterion. Although it is generally accepted that durable immunity is not only related to sero-immunity but also with immunologic memory, a third vaccination is advocated to induce longterm immunity. A vaccine of essentially the same antigenic composition and given in a two-dose regimen, has proven to be effective during an outbreak of paralytic poliomyelitis, caused by polio virus type 1. Observations of adverse events (AE) in vaccination trials, in which IPV produced by the RIVM was given in the control group and the absence of reported AE at RIVM's Medical Center Immunizations, indicate that AE of the present IPV are limited to local reactions and (undefined) irritability in a minority of recipients.