Preeradication vaccine policy options for poliovirus infection and disease control

Abstract

With the circulation of wild poliovirus (WPV) types 1 and 3 continuing more than a decade after the original goal of eradicating all three types of WPVs by 2000, policymakers consider many immunization options as they strive to stop transmission in the remaining endemic and outbreak areas and prevent reintroductions of live polioviruses into nonendemic areas. While polio vaccination choices may appear simple, our analysis of current options shows remarkable complexity. We offer important context for current and future polio vaccine decisions and policy analyses by developing decision trees that clearly identify potential options currently used by countries as they evaluate national polio vaccine choices. Based on a comprehensive review of the literature we (1) identify the current vaccination options that national health leaders consider for polio vaccination, (2) characterize current practices and factors that appear to influence national and international choices, and (3) assess the evidence of vaccine effectiveness considering sources of variability between countries and uncertainties associated with limitations of the data. With low numbers of cases occurring globally, the management of polio risks might seem like a relatively low priority, but stopping live poliovirus circulation requires making proactive and intentional choices to manage population immunity in the remaining endemic areas and to prevent reestablishment in nonendemic areas. Our analysis shows remarkable variability in the current national polio vaccine product choices and schedules, with combination vaccine options containing inactivated poliovirus vaccine and different formulations of oral poliovirus vaccine making choices increasingly difficult for national health leaders.

Figure 1.

Number of countries (a) reporting cases of wild polioviruses (WPVs) by year and endemic status and (b) distribution of number of years individual countries reported cases between 2000 and 2012.⁽³⁾

Figure 1.

Number of countries (a) reporting cases of wild polioviruses (WPVs) by year and endemic status and (b) distribution of number of years individual countries reported cases between 2000 and 2012.⁽³⁾

Figure 2:. Decision tree of national poliovirus routine immunization policy choices*

* Some countries that use OPV apply exclusion criteria from OPV vaccination and use IPV for the small number excluded individuals.

Figure 3:. Decision tree for routine immunization national schedules that only use tOPV, based on current national schedules⁽³³⁾ *

* Always delivered as standalone oral formulation. Some countries that use OPV apply exclusion criteria from OPV vaccination and use IPV for excluded individuals. ** Cuba vaccinates all children under 3 years of age in two annual campaigns, and Japan currently lists a schedule with only 2 doses.

Figure 4:. Decision tree for routine immunization national schedules including any use of IPV, based on current national schedules⁽³³⁾*

(a) Birth and primary immunization options. (b) Booster options. * Some countries that use OPV apply exclusion criteria from OPV vaccination and use IPV for excluded individuals (applies above for some schedules that include OPV).

Figure 4:. Decision tree for routine immunization national schedules including any use of IPV, based on current national schedules⁽³³⁾*

(a) Birth and primary immunization options. (b) Booster options. * Some countries that use OPV apply exclusion criteria from OPV vaccination and use IPV for excluded individuals (applies above for some schedules that include OPV).

Figure 5:. Decision tree of supplemental immunization activity (SIA) policy choices and options*

* Some countries that use OPV apply exclusion criteria from OPV vaccination and use IPV for excluded individuals