annex10_general_faq_ipv_intro.pdf | |
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annex11_technical_faqs.pdf | |
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Why are countries being asked to withdraw OPV type 2?
There are three types of wild poliovirus (WPV) - type 1, type 2 and type 3 - each of which is targeted by a different component of the trivalent oral polio vaccine (tOPV).
Global polio eradication will require stopping the use of all OPV in routine immunization programmes beginning with the withdrawal of the OPV2 component through the replacement of all tOPV with bivalent OPV (bOPV). This is because the risk of paralytic polio disease due to the type 2 component of OPV now outweighs its benefits (after eradication of WPV1 and WPV3 the risks of continued bOPV use will also eventually outweigh the benefits). OPV is a live attenuated vaccine which, in rare cases, can cause paralytic disease, in one of two main ways:
· Vaccine Associated Paralytic Poliomyelitis (VAPP): for every 2.7 million 1st doses of OPV that are administered globally, the vaccine recipient or a close contact is paralyzed due to a reversion of the vaccine virus to neurovirulence. There are an estimated 250 – 500 VAPP cases globally per year. The type 2 component of the vaccine virus accounts for about 40% of these cases.
· circulating Vaccine Derived Poliovirus (cVDPV) outbreaks: these rare outbreaks occur when a vaccine-related virus is passed from person-to-person, mutating along the way and acquiring the wild virus transmissibility and neurovirulence characteristics. Almost all cVDPV outbreaks in recent years have been caused by a type 2 vaccine-derived virus.
Although wild polio virus type 2 was eradicated globally in 1999, vaccine-related type 2 viruses continue to cause the majority of cVDPV outbreaks and cases and many VAPP cases. The WHO Strategic Advisory Group of Experts on immunization (SAGE) has therefore called for a global, coordinated withdrawal of the type 2 component of trivalent OPV from routine immunization programmes in 2016. For countries which use only OPV in their routine immunization programmes, this will require switching from trivalent OPV to bivalent OPV (type 1 and 3) for that purpose.
Why should countries introduce IPV?
Following the withdrawal of the type 2 component of OPV globally, countries that have not introduced IPV would be at an increased risk of outbreaks in the case of reintroduction of a type 2 virus. Such a reintroduction could occur due to the emergence of a cVDPV2 at the time of OPV2 withdrawal or shortly thereafter, or due to breaks in the biocontainment processes in laboratories that have stored the viruses (e.g. for vaccine production, QA/QC, diagnostics). If some degree of population immunity to type 2 poliovirus is not in place, a reintroduction or cVDPV2 emergence could potentially result in a substantial polio outbreak or even re-establishment of transmission globally.
Consequently, the introduction of at least 1 dose of inactivated poliovirus vaccine (IPV) (which contains killed virus components), prior to OPV type 2 withdrawal, will ensure populations are primed against type 2 polio should there be a reintroduction. In addition, in children who have previously received OPV, 1 dose of IPV will boost both their humoural and mucosal immunity to types 1 and 3, potentially hastening the eradication of these two wild viruses.
When do countries need to introduce IPV and switch to bOPV?
SAGE has called for a global withdrawal of type 2-containing OPV as soon as possible, and ideally by the end of 2016. OPV2 withdrawal would be achieved by switching from trivalent OPV (tOPV) to bivalent OPV (bOPV) – containing only types 1 and 3 vaccine poliovirus – in routine immunization programs.
SAGE recommends that prior to the ‘tOPV-bOPV switch’ all countries that currently use only OPV in their routine immunization programmes should introduce at least 1 dose of IPV into their routine schedules (i.e. by end-2015).
This sets the stage for ending bOPV use entirely in 2019-2020.
What schedule should countries be using for IPV, and how many doses are recommended?
SAGE will make its final recommendation on the immunization schedule for IPV in November 2013 on the basis of available evidence. A detailed review of that evidence at June 2013 showed that the optimal timing for administering 1 dose of IPV in a routine immunization schedule is at the DTP3 contact. In countries with a 6, 10, and 14 week immunization schedule, this would mean that IPV would be administered at 14 weeks of age. For countries with a 2, 3, and 4 month schedule, the IPV dose would be administered at 4 months of age. The dose of IPV will be administered in addition to the third dose of OPV, given at the same visit.
What IPV vaccine presentation options exist?
Currently, IPV is prequalified by WHO in 1-dose, 2-dose and 10-dose presentations. WHO expects a 5-dose presentation to be available in 2014. OF NOTE: these products are unpreserved or preserved with 2 phenoxy-ethanol. This means that open vials of this vaccine must be discarded at the end of the immunization session or within 6 hours after opening, whichever comes first. These vaccines are licensed for use as a 0.5 ml dose administered intramuscularly.
IPV-containing hexavalent presentations which use a-cellular pertussis vaccine are also available but at substantially higher cost.
What will the IPV vaccine cost?
WHO anticipates that for the 73 GAVI-eligible and graduating countries the price of the IPV standalone vaccine will be at or slightly below US$ 1.00/dose. For other low and middle income countries, the vaccine is expected to be available at a price of US$1.30-1.50/dose.
The current IPV-containing hexavalent vaccines, which use an acellular pertussis component, are substantially more expensive (priced at US$20-40/dose).
Is the vaccine’s cost expected to drop over time?
Achieving an IPV price substantially below US$ 1.00 per dose will require new products or delivery methods to be licensed. Possible options include the administration of a fractional dose (i.e. 1/5th of a full dose of IPV) through the intradermal (ID) route, or the intramuscular administration of a new IPV product containing a lower level of antigen with an adjuvant to enhance immune response. These options are unlikely to be licensed and accessible before 2016-2018.
However, intradermal administration of IPV brings additional programmatic complexities. Countries that wish to utilize ID IPV will need to ensure they have an appropriately trained and staffed workforce.
The development of an IPV-containing hexavalent vaccine with whole-cell pertussis, which would be affordable for low and middle income country markets, is not expected before 2020.
Is there enough IPV vaccine available globally?
Yes. There is enough production capacity for current IPV standalone products, to meet the needs for all OPV-using countries to introduce one dose of IPV into their routine immunization programme.
However, to ensure sufficient IPV is available when countries are ready to introduce it, it is essential that all countries define their target introduction dates as soon as possible (i.e. by end-2013 if possible but definitely by mid to end-2014).
What financial support is available?
A multi-faceted IPV financing strategy is being developed to assist countries to introduce 1 dose of IPV into their routine immunization programmes by the end of 2015.
This strategy includes a combination of GAVI-assisted procurement, subsidized pricing for introduction in some low and low-middle income countries that are not GAVI-eligible, and self-procurement of low cost products by others. To establish a comprehensive global financing and supply strategy for fast-track IPV introduction using current whole-dose IPV, WHO and its GPEI partners will need country-specific IPV introduction plans and timelines by the end of 2014 at the latest.
How do countries apply for the financial support?
The mechanisms for obtaining financial support will be developed by end-2013; financial support will be available to all countries introducing IPV that can demonstrate a need.
GAVI-eligible and GAVI-graduating countries will likely receive support through the GAVI Alliance, in a process similar to that followed for other new vaccines. Financing mechanisms for non-GAVI eligible countries are being explored. More information on this will be available towards the end of 2013.
Is there technical assistance available to support IPV introduction?
Support for IPV introduction is available from WHO regional office technical focal points as well as from WHO/HQ and immunization partners. Work is underway to develop guidance and tools to help WHO country office staff discuss this issue with their National Immunization Technical Advisory Groups (NITAGs) and MoH counterparts.
Many countries are already planning to introduce other vaccines before 2016. How does IPV introduction impact these plans? There are potential benefits to introducing IPV at the same time as other new vaccines. Studies in Ghana showed efficiencies in cost and time can be gained by introducing two new vaccines at once. Countries planning to introduce other new vaccine(s) in 2014 or 2015 may therefore wish to consider a joint introduction. This option should be discussed with regional immunization staff as soon as possible in order to ensure adequate time for planning.
There are three types of wild poliovirus (WPV) - type 1, type 2 and type 3 - each of which is targeted by a different component of the trivalent oral polio vaccine (tOPV).
Global polio eradication will require stopping the use of all OPV in routine immunization programmes beginning with the withdrawal of the OPV2 component through the replacement of all tOPV with bivalent OPV (bOPV). This is because the risk of paralytic polio disease due to the type 2 component of OPV now outweighs its benefits (after eradication of WPV1 and WPV3 the risks of continued bOPV use will also eventually outweigh the benefits). OPV is a live attenuated vaccine which, in rare cases, can cause paralytic disease, in one of two main ways:
· Vaccine Associated Paralytic Poliomyelitis (VAPP): for every 2.7 million 1st doses of OPV that are administered globally, the vaccine recipient or a close contact is paralyzed due to a reversion of the vaccine virus to neurovirulence. There are an estimated 250 – 500 VAPP cases globally per year. The type 2 component of the vaccine virus accounts for about 40% of these cases.
· circulating Vaccine Derived Poliovirus (cVDPV) outbreaks: these rare outbreaks occur when a vaccine-related virus is passed from person-to-person, mutating along the way and acquiring the wild virus transmissibility and neurovirulence characteristics. Almost all cVDPV outbreaks in recent years have been caused by a type 2 vaccine-derived virus.
Although wild polio virus type 2 was eradicated globally in 1999, vaccine-related type 2 viruses continue to cause the majority of cVDPV outbreaks and cases and many VAPP cases. The WHO Strategic Advisory Group of Experts on immunization (SAGE) has therefore called for a global, coordinated withdrawal of the type 2 component of trivalent OPV from routine immunization programmes in 2016. For countries which use only OPV in their routine immunization programmes, this will require switching from trivalent OPV to bivalent OPV (type 1 and 3) for that purpose.
Why should countries introduce IPV?
Following the withdrawal of the type 2 component of OPV globally, countries that have not introduced IPV would be at an increased risk of outbreaks in the case of reintroduction of a type 2 virus. Such a reintroduction could occur due to the emergence of a cVDPV2 at the time of OPV2 withdrawal or shortly thereafter, or due to breaks in the biocontainment processes in laboratories that have stored the viruses (e.g. for vaccine production, QA/QC, diagnostics). If some degree of population immunity to type 2 poliovirus is not in place, a reintroduction or cVDPV2 emergence could potentially result in a substantial polio outbreak or even re-establishment of transmission globally.
Consequently, the introduction of at least 1 dose of inactivated poliovirus vaccine (IPV) (which contains killed virus components), prior to OPV type 2 withdrawal, will ensure populations are primed against type 2 polio should there be a reintroduction. In addition, in children who have previously received OPV, 1 dose of IPV will boost both their humoural and mucosal immunity to types 1 and 3, potentially hastening the eradication of these two wild viruses.
When do countries need to introduce IPV and switch to bOPV?
SAGE has called for a global withdrawal of type 2-containing OPV as soon as possible, and ideally by the end of 2016. OPV2 withdrawal would be achieved by switching from trivalent OPV (tOPV) to bivalent OPV (bOPV) – containing only types 1 and 3 vaccine poliovirus – in routine immunization programs.
SAGE recommends that prior to the ‘tOPV-bOPV switch’ all countries that currently use only OPV in their routine immunization programmes should introduce at least 1 dose of IPV into their routine schedules (i.e. by end-2015).
This sets the stage for ending bOPV use entirely in 2019-2020.
What schedule should countries be using for IPV, and how many doses are recommended?
SAGE will make its final recommendation on the immunization schedule for IPV in November 2013 on the basis of available evidence. A detailed review of that evidence at June 2013 showed that the optimal timing for administering 1 dose of IPV in a routine immunization schedule is at the DTP3 contact. In countries with a 6, 10, and 14 week immunization schedule, this would mean that IPV would be administered at 14 weeks of age. For countries with a 2, 3, and 4 month schedule, the IPV dose would be administered at 4 months of age. The dose of IPV will be administered in addition to the third dose of OPV, given at the same visit.
What IPV vaccine presentation options exist?
Currently, IPV is prequalified by WHO in 1-dose, 2-dose and 10-dose presentations. WHO expects a 5-dose presentation to be available in 2014. OF NOTE: these products are unpreserved or preserved with 2 phenoxy-ethanol. This means that open vials of this vaccine must be discarded at the end of the immunization session or within 6 hours after opening, whichever comes first. These vaccines are licensed for use as a 0.5 ml dose administered intramuscularly.
IPV-containing hexavalent presentations which use a-cellular pertussis vaccine are also available but at substantially higher cost.
What will the IPV vaccine cost?
WHO anticipates that for the 73 GAVI-eligible and graduating countries the price of the IPV standalone vaccine will be at or slightly below US$ 1.00/dose. For other low and middle income countries, the vaccine is expected to be available at a price of US$1.30-1.50/dose.
The current IPV-containing hexavalent vaccines, which use an acellular pertussis component, are substantially more expensive (priced at US$20-40/dose).
Is the vaccine’s cost expected to drop over time?
Achieving an IPV price substantially below US$ 1.00 per dose will require new products or delivery methods to be licensed. Possible options include the administration of a fractional dose (i.e. 1/5th of a full dose of IPV) through the intradermal (ID) route, or the intramuscular administration of a new IPV product containing a lower level of antigen with an adjuvant to enhance immune response. These options are unlikely to be licensed and accessible before 2016-2018.
However, intradermal administration of IPV brings additional programmatic complexities. Countries that wish to utilize ID IPV will need to ensure they have an appropriately trained and staffed workforce.
The development of an IPV-containing hexavalent vaccine with whole-cell pertussis, which would be affordable for low and middle income country markets, is not expected before 2020.
Is there enough IPV vaccine available globally?
Yes. There is enough production capacity for current IPV standalone products, to meet the needs for all OPV-using countries to introduce one dose of IPV into their routine immunization programme.
However, to ensure sufficient IPV is available when countries are ready to introduce it, it is essential that all countries define their target introduction dates as soon as possible (i.e. by end-2013 if possible but definitely by mid to end-2014).
What financial support is available?
A multi-faceted IPV financing strategy is being developed to assist countries to introduce 1 dose of IPV into their routine immunization programmes by the end of 2015.
This strategy includes a combination of GAVI-assisted procurement, subsidized pricing for introduction in some low and low-middle income countries that are not GAVI-eligible, and self-procurement of low cost products by others. To establish a comprehensive global financing and supply strategy for fast-track IPV introduction using current whole-dose IPV, WHO and its GPEI partners will need country-specific IPV introduction plans and timelines by the end of 2014 at the latest.
How do countries apply for the financial support?
The mechanisms for obtaining financial support will be developed by end-2013; financial support will be available to all countries introducing IPV that can demonstrate a need.
GAVI-eligible and GAVI-graduating countries will likely receive support through the GAVI Alliance, in a process similar to that followed for other new vaccines. Financing mechanisms for non-GAVI eligible countries are being explored. More information on this will be available towards the end of 2013.
Is there technical assistance available to support IPV introduction?
Support for IPV introduction is available from WHO regional office technical focal points as well as from WHO/HQ and immunization partners. Work is underway to develop guidance and tools to help WHO country office staff discuss this issue with their National Immunization Technical Advisory Groups (NITAGs) and MoH counterparts.
Many countries are already planning to introduce other vaccines before 2016. How does IPV introduction impact these plans? There are potential benefits to introducing IPV at the same time as other new vaccines. Studies in Ghana showed efficiencies in cost and time can be gained by introducing two new vaccines at once. Countries planning to introduce other new vaccine(s) in 2014 or 2015 may therefore wish to consider a joint introduction. This option should be discussed with regional immunization staff as soon as possible in order to ensure adequate time for planning.