Inactivated poliovirus vaccine: past and present experience.

Many countries have made use of inactivated poliovirus vaccine (IPV) in their national poliovirus control programs since 1955. Until 1961 IPV was the only vaccine available for the control of poliovirus, but subsequently many countries opted to use the Sabin attenuated poliovirus vaccine (OPV), which was perceived as more effective in preventing intestinal infection and in ensuring community protection by spreading to unvaccinated contacts of vaccinees. Nevertheless, IPV has remained the vaccine of choice in several countries, where experience has shown that it represents a safe and effective option for disease control. IPV limits subsequent infection of the pharynx and intestine in vaccinees, and is able to control circulation of poliovirus in a vaccinated population, providing effective community protection. Furthermore IPV contains only killed virus and cannot cause vaccine-associated paralytic poliomyelitis as OPV sometimes does. This paper reviews the history of the use of IPV, with emphasis on its efficacy and its ability to safely protect communities in which it is used. As the incidence of poliomyelitis declines new control strategies should take account of the knowledge of the use of poliovirus vaccines acquired since 1955.