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Managing the risk of circulating vaccine-derived poliovirus during the endgame: oral poliovirus vaccine needs.

Duintjer Tebbens RJ, Thompson KM - BMC Infect. Dis. (2015)

Bottom Line: The strategy seeks to prevent any cVDPV outbreaks after OPV cessation, although actual events remain stochastic.The model suggests the need to increase trivalent OPV use in SIAs by approximately 40 % or more during the year before OPV2 cessation and to continue bOPV SIAs between the time of OPV2 cessation and OPV13 cessation.Managing the risks of cVDPVs in the polio endgame will require serotype-specific OPV SIAs in some areas prior to OPV cessation and lead to demands for additional doses of the vaccine in the short term that will affect managers and manufacturers.

View Article: PubMed Central - PubMed

Affiliation: Kid Risk, Inc., 10524 Moss Park Rd., Ste. 204-364, Orlando, FL, 32832, USA. rdt@kidrisk.org.

ABSTRACT

Background: The Global Polio Eradication Initiative plans for coordinated cessation of oral poliovirus vaccine (OPV) use, beginning with serotype 2-containing OPV (i.e., OPV2 cessation) followed by the remaining two OPV serotypes (i.e., OPV13 cessation). The risk of circulating vaccine-derived poliovirus (cVDPV) outbreaks after OPV cessation of any serotype depends on the serotype-specific population immunity to transmission prior to its cessation.

Methods: Based on an existing integrated global model of poliovirus risk management policies, we estimate the serotype-specific OPV doses required to manage population immunity for a strategy of intensive supplemental immunization activities (SIAs) shortly before OPV cessation of each serotype. The strategy seeks to prevent any cVDPV outbreaks after OPV cessation, although actual events remain stochastic.

Results: Managing the risks of OPV cessation of any serotype depends on achieving sufficient population immunity to transmission to transmission at OPV cessation. This will require that countries with sub-optimal routine immunization coverage and/or conditions that favor poliovirus transmission conduct SIAs with homotypic OPV shortly before its planned coordinated cessation. The model suggests the need to increase trivalent OPV use in SIAs by approximately 40 % or more during the year before OPV2 cessation and to continue bOPV SIAs between the time of OPV2 cessation and OPV13 cessation.

Conclusions: Managing the risks of cVDPVs in the polio endgame will require serotype-specific OPV SIAs in some areas prior to OPV cessation and lead to demands for additional doses of the vaccine in the short term that will affect managers and manufacturers.

No MeSH data available.


Related in: MedlinePlus

Impact of SIA intensity on cVDPV outbreaks after OPV2 cessation and OPV13 cessation showing the total paralytic incidence (i.e., including paralysis from OPV-related viruses in all reversion stages) in a block with a cVDPV outbreak in the event of insufficient homotypic OPV SIA. a Paralytic incidence due to serotype 2 polioviruses after OPV2 cessation in 2016, with or without tOPV intensification. b Paralytic incidence due to serotype 1 polioviruses after OPV13 cessation in 2019, for different scenarios of SIA frequency between January 1, 2017
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Fig1: Impact of SIA intensity on cVDPV outbreaks after OPV2 cessation and OPV13 cessation showing the total paralytic incidence (i.e., including paralysis from OPV-related viruses in all reversion stages) in a block with a cVDPV outbreak in the event of insufficient homotypic OPV SIA. a Paralytic incidence due to serotype 2 polioviruses after OPV2 cessation in 2016, with or without tOPV intensification. b Paralytic incidence due to serotype 1 polioviruses after OPV13 cessation in 2019, for different scenarios of SIA frequency between January 1, 2017

Mentions: Figure 1a shows the expected paralytic cases from serotype 2 polioviruses (PV2) for 2016-2019 with (solid blue curve) and without (red dashed curve) tOPV intensification prior to OPV2 cessation. The failure to intensify tOPV use prior to OPV2 cessation increases both the risk of missing the target date for OPV2 cessation, [30, 40] and the risk of cVDPV2 outbreaks after OPV2 cessation (Fig. 1a). Intensification of tOPV SIAs prior to OPV2 cessation prevents cVDPV2 outbreaks after OPV2 cessation such that the solid line becomes and remains 0 soon after OPV2 cessation. For the dashed curve without tOPV intensification, a cVDPV2 outbreak originates from a single subpopulation modeled as the under-vaccinated communities within one of the blocks representing the last reservoirs of WPV transmission (i.e., high R0, low RI coverage, poor SIA quality). Assumed aggressive response that involves block-wide SIAs [25] controls the outbreak in the subpopulation and prevents spread beyond it. The cVDPV2 outbreak in Fig. 1a results in over 50 expected paralytic cases and requires approximately 120 million filled mOPV2 doses from the outbreak response vaccine stockpile within the approximately 3.5-month duration of the outbreak response.Fig. 1


Managing the risk of circulating vaccine-derived poliovirus during the endgame: oral poliovirus vaccine needs.

Duintjer Tebbens RJ, Thompson KM - BMC Infect. Dis. (2015)

Impact of SIA intensity on cVDPV outbreaks after OPV2 cessation and OPV13 cessation showing the total paralytic incidence (i.e., including paralysis from OPV-related viruses in all reversion stages) in a block with a cVDPV outbreak in the event of insufficient homotypic OPV SIA. a Paralytic incidence due to serotype 2 polioviruses after OPV2 cessation in 2016, with or without tOPV intensification. b Paralytic incidence due to serotype 1 polioviruses after OPV13 cessation in 2019, for different scenarios of SIA frequency between January 1, 2017
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4582727&req=5

Fig1: Impact of SIA intensity on cVDPV outbreaks after OPV2 cessation and OPV13 cessation showing the total paralytic incidence (i.e., including paralysis from OPV-related viruses in all reversion stages) in a block with a cVDPV outbreak in the event of insufficient homotypic OPV SIA. a Paralytic incidence due to serotype 2 polioviruses after OPV2 cessation in 2016, with or without tOPV intensification. b Paralytic incidence due to serotype 1 polioviruses after OPV13 cessation in 2019, for different scenarios of SIA frequency between January 1, 2017
Mentions: Figure 1a shows the expected paralytic cases from serotype 2 polioviruses (PV2) for 2016-2019 with (solid blue curve) and without (red dashed curve) tOPV intensification prior to OPV2 cessation. The failure to intensify tOPV use prior to OPV2 cessation increases both the risk of missing the target date for OPV2 cessation, [30, 40] and the risk of cVDPV2 outbreaks after OPV2 cessation (Fig. 1a). Intensification of tOPV SIAs prior to OPV2 cessation prevents cVDPV2 outbreaks after OPV2 cessation such that the solid line becomes and remains 0 soon after OPV2 cessation. For the dashed curve without tOPV intensification, a cVDPV2 outbreak originates from a single subpopulation modeled as the under-vaccinated communities within one of the blocks representing the last reservoirs of WPV transmission (i.e., high R0, low RI coverage, poor SIA quality). Assumed aggressive response that involves block-wide SIAs [25] controls the outbreak in the subpopulation and prevents spread beyond it. The cVDPV2 outbreak in Fig. 1a results in over 50 expected paralytic cases and requires approximately 120 million filled mOPV2 doses from the outbreak response vaccine stockpile within the approximately 3.5-month duration of the outbreak response.Fig. 1

Bottom Line: The strategy seeks to prevent any cVDPV outbreaks after OPV cessation, although actual events remain stochastic.The model suggests the need to increase trivalent OPV use in SIAs by approximately 40 % or more during the year before OPV2 cessation and to continue bOPV SIAs between the time of OPV2 cessation and OPV13 cessation.Managing the risks of cVDPVs in the polio endgame will require serotype-specific OPV SIAs in some areas prior to OPV cessation and lead to demands for additional doses of the vaccine in the short term that will affect managers and manufacturers.

View Article: PubMed Central - PubMed

Affiliation: Kid Risk, Inc., 10524 Moss Park Rd., Ste. 204-364, Orlando, FL, 32832, USA. rdt@kidrisk.org.

ABSTRACT

Background: The Global Polio Eradication Initiative plans for coordinated cessation of oral poliovirus vaccine (OPV) use, beginning with serotype 2-containing OPV (i.e., OPV2 cessation) followed by the remaining two OPV serotypes (i.e., OPV13 cessation). The risk of circulating vaccine-derived poliovirus (cVDPV) outbreaks after OPV cessation of any serotype depends on the serotype-specific population immunity to transmission prior to its cessation.

Methods: Based on an existing integrated global model of poliovirus risk management policies, we estimate the serotype-specific OPV doses required to manage population immunity for a strategy of intensive supplemental immunization activities (SIAs) shortly before OPV cessation of each serotype. The strategy seeks to prevent any cVDPV outbreaks after OPV cessation, although actual events remain stochastic.

Results: Managing the risks of OPV cessation of any serotype depends on achieving sufficient population immunity to transmission to transmission at OPV cessation. This will require that countries with sub-optimal routine immunization coverage and/or conditions that favor poliovirus transmission conduct SIAs with homotypic OPV shortly before its planned coordinated cessation. The model suggests the need to increase trivalent OPV use in SIAs by approximately 40 % or more during the year before OPV2 cessation and to continue bOPV SIAs between the time of OPV2 cessation and OPV13 cessation.

Conclusions: Managing the risks of cVDPVs in the polio endgame will require serotype-specific OPV SIAs in some areas prior to OPV cessation and lead to demands for additional doses of the vaccine in the short term that will affect managers and manufacturers.

No MeSH data available.


Related in: MedlinePlus