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.
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.
Authors: Radboud J Duintjer Tebbens; Mark A Pallansch; Stephen L Cochi; Derek T Ehrhardt; Noha H Farag; Stephen C Hadler; Lee M Hampton; Maureen Martinez; Steve G F Wassilak; Kimberly M Thompson Journal: Risk Anal Date: 2018-01-03 Impact factor: 4.000
Authors: Radboud J Duintjer Tebbens; Lee M Hampton; Steven G F Wassilak; Mark A Pallansch; Stephen L Cochi; Kimberly M Thompson Journal: J Vaccines Vaccin Date: 2016-10-03
Authors: Dominika A Kalkowska; Richard Franka; Jeff Higgins; Stephanie D Kovacs; Joseph C Forbi; Steven G F Wassilak; Mark A Pallansch; Kimberly M Thompson Journal: Risk Anal Date: 2020-04-29 Impact factor: 4.000
Authors: Radboud J Duintjer Tebbens; Mark A Pallansch; Steven G F Wassilak; Stephen L Cochi; Kimberly M Thompson Journal: PLoS One Date: 2015-06-11 Impact factor: 3.240
Authors: Radboud J Duintjer Tebbens; Mark A Pallansch; Stephen L Cochi; Steven G F Wassilak; Kimberly M Thompson Journal: BMC Infect Dis Date: 2015-09-24 Impact factor: 3.090