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Immunization Systems Management Group (IMG)

Inactivated Polio Vaccine (IPV) Comprehensive technical module R ationale for IPV introduction & OPV withdrawal in relation to Objective 2 of The Polio Eradication & Endgame Strategic Plan. Immunization Systems Management Group (IMG). Version date: February 10, 2014.

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Immunization Systems Management Group (IMG)

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  1. Inactivated Polio Vaccine (IPV)Comprehensive technical moduleRationale for IPV introduction & OPV withdrawal in relation to Objective 2 of The Polio Eradication & Endgame Strategic Plan Immunization Systems Management Group (IMG) Version date: February 10, 2014

  2. Glossary of terms & abbreviations • cVDPV Circulating Vaccine-Derived Poliovirus • DTP3 Diphtheria Tetanus Pertussis (third dose) • GPEI Global Polio Eradication Initiative • IMG Immunization Systems Management Group • IPV Inactivated Polio Vaccine • OPV Oral polio vaccine • bOPV (bivalent, contains types 1 and 3) • mOPV (monovalent) • OPV1 (type 1 component of OPV) • OPV2 (type 2 component of OPV) • OPV3 (type 3 component of OPV) • SAGE Strategic Advisory Group of Experts on Immunization • VAPP Vaccine-associated paralytic poliomyelitis • VDPV Vaccine-derived poliovirus • WHA World Health Assembly • WHO World Health Organization • WPV Wild poliovirus IPV introduction

  3. Definitions IPV introduction

  4. Objectives of this module Note: this is a comprehensive stand-alone deck of slides with an accompanying document • Provide Technical background on Polio & Polio vaccines as it relates to Objective 2 of GPEI’s Polio Eradication & Endgame Strategic Plan • Review Rationale for OPV cessation • Review Rationale for IPV introduction • Review of SAGE recommendations for IPV introduction IPV introduction

  5. Key messages for IPV introduction & OPV cessation • IPV recommended by SAGE • All countries introduce at least one dose of IPV into the routine immunization system before the tOPV-bOPV switch • OPV cessation crucial • OPV cessation must occur for the world to be polio free because OPV in rare cases can cause paralytic disease • OPV cessation--2 phases • Removal of type 2 in 2016 (tOPV to bOPV switch globally) • bOPV cessation in 2018-2019 (complete cessation of OPV) • IPV rationale • Ensures that a substantial proportion of the population is protected against type 2 polio after OPV2 cessation • Added IPV benefits • Mitigates risks of type 2 reintroduction in association with OPV2 cessation & facilitates polio eradication by boosting immunity to types 1&3 • IPV clarifications • Recommended for routine immunization…not campaigns • Recommended in addition to OPV…not replacing any OPV IPV introduction

  6. GPEI Accomplishment: Significant Decline in Polio-paralyzed Children, 1988-2013* *as of 31 December 2013 IPV introduction

  7. As wild polioviruses are eradicated, number of vaccine-derived cases exceedswild poliovirus cases A hypothetical scenario of estimated VDPV cases compared to reported cases of wild poliovirus (as of 31 December, 2013) IPV introduction

  8. The Polio Eradication & Endgame Strategic Plan 2013-2018 The Plan differs from previous eradication plans “complete the eradication and containment of all wild, vaccine-related, andSabin poliovirusessuch that no child ever again suffers paralytic poliomyelitis.” IPV introduction

  9. The Plan has four objectives IPV introduction

  10. Objective 2 of The Plan addresses the Endgame through three distinct stages 2019-2020 2016 Before end 2015 Ongoing STRENGTHENING of routine immunization services IPV introduction

  11. Timeline for implementation of Objective 2, the Endgame Last wild polio case tOPV-bOPV switch Global certification Stop bOPV Anticipated timeline 2013 2014 2015 2016 2017 2018 2019-2020 Phase in IPV IPV in routine immunization • Before end of 2015: introduce one dose of IPV in immunization programs of all countries, prior to tOPV-bOPV switch • 2016:tOPV-bOPV switch globally • 2019-2020: withdrawal of bOPVafter the world is certified polio-free in 2018 IPV introduction

  12. Technical Rationale for Oral Polio Vaccine (OPV) Cessation Key Messages • Because OPV in rare cases can cause paralytic disease, OPV cessation must occur for the world to be polio free. • OPV cessation will occur globally in two phases: • removal of type 2 component (switch from tOPV to bOPV) in 2016 • followed by bOPV withdrawal and cessation of OPV use in 2018-2019. IPV introduction

  13. Oral Polio Vaccines (OPV) in routine and supplementary immunization activities globally • Types of OPV • Trivalent OPV (tOPV): types 1, 2, and 3 • Bivalent OPV (bOPV): types 1 and 3 • Monovalent OPV (mOPV): types 1 or 2 or 3 • Currently, TRIVALENT is the most commonly used OPVin routine immunization globally, while BIVALENT is more commonly used in supplementary immunization activities. IPV introduction

  14. Types of polioviruses • Wild • 99% reduction in cases of wild poliovirus since 1988 • Type 1 (341 cases as of 20 November 2013†) • Type 2 (eliminated worldwide in 1999) • Type 3 (none detected since November 2012) • VAPP** • Vaccine-associated paralytic poliomyelitis (VAPP)** • Estimated ~250-500 globally per year • Type 2 accounts for about 40% of VAPP • OPV related • VDPVs* • Vaccine derived polioviruses (VDPV) • Most are circulating VDPVs (cVDPVs)* • ~49-184 per year since 2008 (through 20 Nov 2013) • Type 2 cVDPVsaccount for 97% of cVDPVs † More up-to-date numbers can be found at http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx *Other extremely rare VDPVs include primary immunodeficiency VDPVs (iVDPVs) and ambiguous VDPVs (aVDPVs) **Refers to spontaneous reversion to neurovirulence of one of the attenuated viruses in OPV. VAPP occurs in OPV recipients or their close contacts in contrast to cVDPVs which are widely transmitted in a community and are not likely to be related to contact with a recent vaccine recipient. IPV introduction

  15. What does it mean for the world to be polio-free? • Eradication • Endgame • Plan refers to wild virus • Plan refers to management of VDPVs and VAPP • Complete interruption of transmission and elimination of all polio disease • Wild polioviruses • Vaccine-derived polioviruses (VDPVs) • Vaccine-associated paralytic poliomyelitis (VAPP) • Eradication & Endgame Strategic Plan 2013-2028 refers to both wild and vaccine-derived polioviruses IPV introduction

  16. Rationale for continuing use of OPV until Polio Eradication & Global Certification • Wild poliovirus still circulating • As long as there are susceptible persons in other countries, there is risk of export of the virus to these countries.” • Endemic in 3 countries – reservoirs for re-infecting others (Pakistan, Afghanistan, Nigeria) • In 2013, polio cases in 5 other countries previously polio free countries (Somalia, Kenya, Ethiopia, Cameroon, Syria) • Eradication requires OPV • OPV is a critical component of the eradication strategy until polio transmission is interrupted globally & the world is certified polio-free, • Risk of polio spread into other regions of the world is real without the continued use of OPV • OPV is appropriate for eradication • Inexpensive • Easy to administer • Offers good oral and intestinal immunity—needed for interruption of person to person transmission IPV introduction

  17. Objective 2 of the Plan calls for a phased withdrawal and containment of OPV globally • Phase 1 • 2016 • Remove type 2 by switch from tOPV to bOPV… OPV withdrawal Type 2 • Phase 2 • 2019-2020 • …followed by bOPV withdrawal and cessation of OPV use in 2019-2020 All OPV IPV introduction

  18. Rationale for removing type 2 component of OPV (OPV2) • Risks of OPV2 far outweigh the benefits • Thus, need to remove OPV2, but need to maintain population immunity against type 2 with IPV prior to OPV2 cessation • Type 2 poliovirus apparently eradicated since 1999 (last case detected in Aligarh, India) • New diagnostics and experience suggest that type 2 cause >95% of cVDPVs • Type 2 causes 40% of VAPP today • Type 2 component of OPV interferes with immune response to types 1 and types 3 IPV introduction

  19. Rationale for retaining Types 1 & Types 3 components of OPV (bivalent OPV) until global certification of polio eradication • Type 1 causes all polio cases related to wild virus today • Few VDPV cases are type 1 • Few VAPP cases in immunocompetent individuals • Type 3 last detected in November, 2012 (as of 20 November 2013) • Few VDPV cases are type 3 • Most VAPP cases (60%) in immunocompetent persons are type 3 • While lack of detection since November 2012 is promising, the period without detection to date is not long enough to assume eradication—due to potential silent transmission, certification of eradication requires at least 3 years without detection of virus. IPV introduction

  20. Risks associated with OPV2 cessation • Short-term risks • Time-limited risk of cVDPV2 emergence, highest 1-2 years after OPV2 cessation • Medium & long term risks • Poliovirus re-introduction from a vaccine manufacturing site, research facility, immune deficient persons, diagnostic laboratory, or bioterrorism Two main risks are associated with OPV2 cessation These risks are mitigated by strengthening routine immunization and introduction of IPV IPV introduction

  21. Role of OPV post-eradication Maintaining a stockpile of monovalent OPVs (mOPV1, mOPV2, mOPV3) Using mOPVs to control outbreaks of cVDPVs or re-introduction from a manufacturing site, research facility, or diagnostic laboratory Stockpile of mOPVs would allow a type-specific response for rapid interruption of outbreak IPV introduction

  22. Technical Rationale for Introduction for Inactivated Polio Vaccine (IPV) Key Messages • Introducing IPV before the tOPV-bOPV switch in 2016 will ensure that a substantial proportion of the population is protected against type 2 polio after OPV2 cessation and mitigate risks associated with OPV2 cessation • IPV is recommended for routine immunization programmes & not campaigns • IPV is given in addition to OPV doses and does not replace any OPV doses IPV introduction

  23. Planned use of IPV: SAGE Recommendations • SAGE recommended that all countries introduce at least 1 dose of IPV in their routine immunization programmes to mitigate the risks associated with the withdrawal of type 2 component of OPV • Single dose of IPV at 14 weeks of agewith DTP3, in addition to OPV3 or OPV4. • Countries have flexibility to consider alternative schedules • All endemic and other high risk countries should develop a plan for IPV introduction by mid-2014 and all OPV-only using countries by end-2014 WER, 3 Jan 2014, vol. 89, 1 (pp 1-20): at http://www.who.int/wer/2014/wer8901/en/index.html IPV introduction

  24. Features of Inactivated Polio Vaccine (IPV) • Not a live vaccine – no risk of VAPP or VDPVs • Must be administered by intramuscular or subcutaneous injection • Trivalent – produces antibodies to types 1, 2 and 3 poliovirus • A high proportion of vaccinees, generally > 95% of children, have serum neutralizing antibodies after 3 doses to all three polio serotypes • Appears equivalent to OPV in inducing pharyngeal immunity • Inferior to OPV in inducing gut immunity • More costly to produce than OPV • Partners are working towards achieving the lowest possible price for GAVI and non-GAVI countries. • Collaborations & investigations underway to explore two “low cost” IPV options: • fractional dose intradermal • adjuvanted intramuscular IPV • GAVI will cover the full cost of purchase for GAVI eligible and graduating countries IPV introduction

  25. Rationale for introducing at least one dose of IPVprior to the tOPV-bOPV switch Introducing IPV before the tOPV-bOPV switch in 2016 will ensure that a substantial proportion of the population is protected against type 2 polio after OPV2 cessation. One dose of IPV will: IPV • Reduce risks associated with OPV2 cessation • Lower risk of re-emergence of type 2 polioviruses • Facilitate interruption of transmission with the use of monovalent OPV2 if type 2 outbreaks occur • Boost immunity against types 1 & 3 thus hastening polio eradication IPV introduction

  26. Individual protection against paralytic disease induced by IPV – REDUCE RISKS IPV IPV introduction

  27. Impact of one dose of IPV* * Estı´variz CF et al. Lancet 2012; 12(2):128-35 Primary role of one dose of IPV is intended to be a RISK MITIGATION strategy to reduce risk of re-emergence of type 2 polioviruses after OPV2 cessation Seroconversion against type 2 after one dose of IPV ranges from 32-63%. Persons who seroconvert should be protected against paralytic polio Seroconversion rates are higher when vaccine is administered later in infancy presumably because of waning maternal antibody Persons who seroconvert should be protected against paralytic polio IPV introduction

  28. Rationale for administering IPV after 14 weeks of age, in the context of the Endgame Plan • The immune response to intramuscularly administered IPV varies based on the number of administered doses (higher with more doses) and the age at vaccination (higher with delayed immunization). • 3 doses: ~100% against all 3 serotypes • 2 doses: ~90% against all 3 serotypes, when administered >8 weeks of age • 1 dose: ~19%-46% against Type 1, 32%-63% against Type 2, and 28%-54% against Type 3 poliovirus. • It is important to note that immune response to one dose of IPV is substantially higher, particularly against Type 2 poliovirus (63%) when administered at 4 months of age compared to 6 weeks to 2 months of age (32%-39%). • Thus, SAGE recommends a single dose of IPV at 14 weeksor first contact afterwards, or with DTP3/OPV3 or for countries administering a birth dose of OPV, at the time of the OPV4 dose IPV introduction

  29. Poliovirus type 2 seroconversion & priming • In a study from Cuba, among those who did not seroconvert after 1 dose of IPV, 98% had a priming response to a subsequent dose of IPV--that is, they developed significant antibody responses within 7 days of subsequent exposure to IPV. • Persons without priming who are seronegative would not be expected to make detectable antibody for at least 10-14 days or longer after immunization. • Persons who are seronegative but primed may also be protected against paralytic polio although data are conflicting as to whether priming alone is protective. Sutter RW – Presentation to SAGE IPV Working Group June 2013 based on: Resik S et al N Engl J Med 2013;368:416-24 IPV introduction

  30. IPV Evidence: One IPV dose prevents VAPP in Hungary. Implies priming induces clinical protection. In 1992, single-dose IPV at 3 mos of age, before OPV receipt VAPP number of cases In 2006, IPV-only schedule Year In contrast, effectiveness against type 1 in Senegal was 36% (0%-67%) implying that seroconversion is the predictor of immunity. Sutter RW – Presentation to SAGE IPV Working GroupJune 2013 IPV introduction

  31. Outbreak control with mOPV2 in a population which previously received IPV -- REDUCE RISKS IPV

  32. IPV Evidence: What impact is one dose of IPV in routine immunization likely to have during SIAs in outbreak situations? Comparison of 2-dose response, Faden et al, JID, 1990**These data are based on a US study in Baltimore and Buffalo. Impact on seroconversion of IPV followed by OPV is similar to IPV-IPV or OPV-OPV Thus, with one dose of IPV a proportion of the population is already immune. Use of mOPV in an outbreak control setting in a population who received a dose of IPV is likely to lead to higher immunity levels than a single dose of mOPV in a completely susceptible population Thus, population immunity thresholds to terminate poliovirus transmission are more likely to be reached after a dose of IPV followed by mOPV compared to a single dose of mOPVonly in response to an outbreak. IPV introduction

  33. IPV in reducing transmission of polioviruses – Interrupt Transmission IPV

  34. OPV challenge studies: Shedding of poliovirus in IPV versus OPV vaccinees • IPV is equivalent to OPV in reducing oral shedding but is inferior to OPV in reducing intestinal shedding. • To the degree that polioviruses are transmitted orally, IPV should be equivalent to OPV. • To the extent that polioviruses are transmitted via the fecal-oral route, IPV is likely to be inferior to OPV. From Vidor E et. al, Poliovirus Vaccine – Inactivated, Vaccines 6th edition, Elsevier, 2013 IPV introduction

  35. Although IPV may not be as effective as OPV in decreasing prevalence of poliovirus excretion in stool, IPV may still decrease transmission IPV does reduce the duration of shedding and the amount of virus shed in the stool. Thus, IPV should decrease the spread of polioviruses if they are introduced, compared to a fully unvaccinated population. IPV introduction From Sutter et al. Poliovirus vaccine-live, Vaccines 6thed, Elsevier, 2013

  36. IPV in boosting immunity in OPV primed individuals – Hastens Eradication IPV

  37. A single dose of IPV after prior doses of tOPV boosts immunity to types 1 & 3 • IPV could also play a role in the eradication efforts, in conjunction with bOPV, by boosting immunity against type 1 and 3 polioviruses in polio endemic countries and countries where poliovirus circulation has been reestablished. • Immune response to Types 1 & 3 significantly better with IPV at 6 months of age in children who received three prior doses of tOPVin Ivory Coast but were still seronegative* ** Fourth dose at 6 months • Seroconversion after one dose of IPV in seronegative children with prior OPV substantially higher than would be expected with one dose of IPV in polio vaccine naïve children. • Further, IPV in persons with prior OPV induces boosts in mucosal immunity. • Results from a similar study in Moradabad showed 91%-100% seroconversion for types 3 and 2 respectively among those who received IPV** *Moriniere BJ et al. Lancet 1993;341:1545-50, ** Estı´variz CF et al. Lancet 2012; 12(2):128-35, IPV introduction

  38. tOPV: 3 rings of protection against types 1, 2, and 3 tOPV-bOPV switch bOPV + IPV IPV adds protection against type 2 & boosts immunity to 1 & 3 (enhancing bOPV effect) bOPV + IPV Schematic description of technical rationale for use of at least one dose of IPV as part of the Endgame Strategy bOPV 2 rings of protection against types 1 and 3 Potential Type 2 outbreak requiring mOPV2 mOPV2 mOPV2 Type 1 bOPV + mOPV2 Protection against type 2 provided by supplementary use of mOPV2 in the setting of an outbreak Type 2 bOPV + IPV + mOPV2 bOPV& mOPV2effect is enhanced in an IPV population thus facilitating outbreak control Type 3

  39. IPV Presentations and Formulations • Stand-alone IPV • Only WHO prequalified formulation • 1-dose and 10-dose available now • 5-dose expected in late 2014 • Preservative : 2PE does not allow for Multi dose vial Policy application • Combination products • Tetravalent, pentavalent, hexavalent available • Combination with whole-cell pertussis not currently available • Substantially higher cost than stand-alone IPV IPV introduction

  40. Example 6-10-14 week schedule with IPV 1st contact after 14 weeks • Single dose of IPV at 14 weeksor first contact afterwards • All children who are behind on their schedule should receive one dose of the IPV at the first immunization contact after 14 weeks • Countries have flexibility to consider alternative schedules (e.g. earlier IPV administration based on local conditions) * Rotavirus vaccine may be administered in 2 or 3 doses, depending on the country schedule IPV introduction

  41. Administration of Inactivated Polio Vaccine (IPV) • IPV is administered by intramuscular injection (IM) or subcutaneously (SQ) in a dose of 0.5 ml into the outer part of the thigh • When given at the same visit, IPV and other injectable vaccines should be given at different injection sites at least 2 cm apart • For example, if IPV, Pentavalentvaccine, and Pneumococcal vaccine are to be given during the same visit, IPV and Pneumococcal should be in one thigh 2 cm apart and the Pentavalent vaccine (more reactogenic) in the other thigh • IPV should not be mixed with other vaccines in the same vial or syringe • IPV can be administered to prematurely born infants and children with immunodeficiencies (e.g., HIV, congenital or acquired immunodeficiency, sickle cell disease) IPV introduction

  42. Multiple Injections: Acceptability and Safety *http://www.cdc.gov/vaccinesafety/Vaccines/multiplevaccines.html *http://www.cmaj.ca/content/182/18/E843.full • Recently, more low and middle income countries have begun using multiple vaccine injections with the addition of pneumococcal vaccine and IPV • Substantial evidence has reinforced the well-established record of safety and acceptance of multiple injections from countries using multiple injections* • For example, US infants often receive 3 or more injections during each of the primary series vaccination visits • Giving a child several vaccinations during the same visit offers three major advantages: • Immunizing children as soon as possible provides protection during the vulnerable early months of their lives. • Giving several vaccinations at the same time means parents and caregivers do not need to make as many vaccination visits. 1 • It means that health care providers are able to more efficiently provide and deliver other health services by reducing the time they need to spend providing vaccinations. IPV introduction

  43. Specific notes on the recommended IPV schedule* • IPV does not replace ANY of the OPV doses – that is, IPV will be given in addition to OPV and OPV will continue to be used per current practice for now • IPV is recommended for routine immunization programmes and not campaigns because injections are difficult to accommodate in campaigns against polio • The higher the IPV coverage the better, but even low coverage will provide direct benefit to those vaccinated and greatly facilitate building population immunity in an emergency response *from 7th Meeting of the SAGE Polio Working Group, October 18-19, 2013 IPV introduction

  44. Planned use of IPV: IPV Rationale Summary • IPV induces immunity in a proportion of children which will protect them against polio caused by vaccine viruses (VAPP and cVDPVs) and polio caused by wild poliovirus • IPV should lower risk of re-emergence of type 2 polioviruses • IPV in conjunction with bOPVwill decrease the number of cases of VAPP caused by types 1 and 3 • IPV will boost immunity to types 1 and 3 which should hasten eradication of types 1 and 3 wild polioviruses and reduce polio disease caused by types 1 and 3 cVDPVs • IPV by inducing immunity to type 2 will facilitate outbreak control with mOPV2 should type 2 viruses be reintroduced • A proportion of the population will already be immune resulting in a higher level of immunity after a dose of mOPV2 in outbreak control than after a dose of mOPV2 to contain an outbreak in a completely susceptible population • The higher the IPV coverage the better, but even low coverage will provide direct benefit to those vaccinated and greatly facilitate building population immunity in an emergency response IPV introduction

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