Modeling strategies to increase population immunity and prevent poliovirus transmission in the high-risk area of northwest Nigeria

J Infect Dis. 2014 Nov 1;210 Suppl 1:S412-23. doi: 10.1093/infdis/jit834.


Background: Nigeria continues to struggle in its efforts to eliminate circulating live polioviruses using oral poliovirus vaccine (OPV).

Methods: We modeled population immunity, and we estimated cases and the timing of transmission die-out for numerous policies that could accelerate the elimination of wild poliovirus type 1 (WPV1) and help Nigeria manage the risks of circulating vaccine-derived polioviruses (cVDPVs). We used a differential-equation based poliovirus transmission and OPV evolution model focused on northwest Nigeria to characterize the impact and trade-offs of potential vaccination strategies, including the introduction of inactivated poliovirus vaccine (IPV).

Results: Northwest Nigeria appears close to reaching the threshold of population immunity it must exceed to stop WPV1 transmission if it continues immunizing previously under-vaccinated children. Avoiding type 2 cVDPVs (cVDPV2s) will depend on using sufficient amounts of trivalent OPV, which will also reduce the risks of cVDPV2s after coordinated cessation of type 2-containing OPV (OPV2). Using IPV during the OPV cessation period may increase population immunity, but it leads to a much lower impact on cVDPV risks than ensuring sufficient trivalent OPV use prior to OPV2 cessation.

Conclusions: Northwest Nigeria needs to intensify and sustain its immunization efforts to achieve and maintain higher levels of population immunity.

Keywords: IPV; OPV; eradication; polio; population immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Models, Statistical
  • Nigeria / epidemiology
  • Poliomyelitis / immunology
  • Poliomyelitis / prevention & control*
  • Poliomyelitis / transmission*
  • Poliovirus / isolation & purification*
  • Poliovirus Vaccine, Oral / administration & dosage*
  • Poliovirus Vaccine, Oral / immunology*
  • Vaccination / methods*
  • Vaccination / statistics & numerical data*
  • Young Adult


  • Poliovirus Vaccine, Oral