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Inactivated Polio Vaccine (IPV)

Comprehensive technical module

Rationale 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

04/19/2023 IPV introduction 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


Definitions

Technical term Definition (in the context of these slides)

Fractional Dose A fractional dose is a dose that uses less antigen (1/5th or 1/3rd) for cost or supply sparing measures. With IPV, fractional doses are being evaluated by administration into the skin (intradermal, ID). In contrast, full dose is usually administered into the muscle (intramuscular, IM) or subcutaneous tissue (SC or SQ).

Intestinal Immunity

Intestinal shedding refers to the amount of virus an infected person “sheds” or passes on through their intestine (and fecal matter). Wild polioviruses and vaccine viruses can be spread from person to person this way, if there is no intestinal immunity. In developing countries the major mode of transmission is thought to be fecal shedding to others with oral ingestion.

Oral-pharyngeal shedding

Oral-pharyngeal shedding refers to the amount of virus an infected person “sheds” or passes on through their oral secretions (nose and mouth). In industrialized countries the major mode of transmission is thought to be oral secretion to oral ingestion.

Priming Children who do not seroconvert after a first dose are considered primed if they seroconvert within 7 days of a 2nd dose.

Seroconversion Seroconversion is defined as the development of antibodies in blood serum as a result of infection or immunization and is correlated with protection


1. 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

2. Review of SAGE recommendations for IPV introduction

Objectives of this module

Note: this is a comprehensive stand-alone deck of slides with an accompanying document


Key messages for IPV introduction & OPV cessation

• All countries introduce at least one dose of IPV into the routine immunization system before the tOPV-bOPV switch

IPV recommended by SAGE

• OPV cessation must occur for the world to be polio free because OPV in rare cases can cause paralytic diseaseOPV cessation crucial

• Removal of type 2 in 2016 (tOPV to bOPV switch globally)• bOPV cessation in 2018-2019 (complete cessation of

OPV)OPV cessation--2 phases

• Ensures that a substantial proportion of the population is protected against type 2 polio after OPV2 cessationIPV rationale

• Mitigates risks of type 2 reintroduction in association with OPV2 cessation & facilitates polio eradication by boosting immunity to types 1&3

Added IPV benefits

• Recommended for routine immunization…not campaigns• Recommended in addition to OPV…not replacing any OPVIPV clarifications

604/19/2023 IPV introduction

GPEI Accomplishment: Significant Decline in Polio-paralyzed Children, 1988-2013*

*as of 31 December 2013

1988

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18001604

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As wild polioviruses are eradicated, number of vaccine-derived cases exceeds wild poliovirus cases

A hypothetical scenario of estimated VDPV cases compared to reported cases of wild poliovirus (as of 31 December, 2013)

2009 2010 2011 2012 2013 2014 2015 2016 2017 20180

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Wild poliovirus cases

Vaccine-derived poliovirus cases (VDPVs)/VAPP

Po

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Post interruption of WPV transmission

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?


The Polio Eradication & Endgame Strategic Plan 2013-2018

“complete the eradication and containment of all wild, vaccine-related, and Sabin polioviruses such that no child ever again suffers paralytic poliomyelitis.”

The Plan differs from previous eradication

plans


The Plan has four objectives

• Detect and interrupt all poliovirus transmission1

• Strengthen immunization systems, withdraw oral polio vaccines (OPV), and introduce inactivated polio vaccine (IPV)2

• Contain poliovirus and certify interruption of transmission3

• Plan polio’s legacy4


Objective 2 of The Plan addresses the Endgame through three distinct stages

Introduction• at least one dose of IPV• into routine immunization

Switch• tOPV to bOPV

Withdrawal• of bOPV & routine OPV

useBefore

end 2015

2016

2019-2020

Ongoing STRENGTHENING of routine immunization services


Timeline for implementation of Objective 2, the Endgame

Last wild polio case

IPV in routine immunization

2013 2014 2015 2016 2017 2018 2019-

2020

Anticipated timeline

Phase in IPV

Before end of 2015: introduce one dose of IPV in immunization programs of all

countries, prior to tOPV-bOPV switch

tOPV-bOPV switch

2016: tOPV-bOPV switch globally

Global certification

StopbOPV

2019-2020: withdrawal of bOPV after the world is certified polio-free in 2018


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.


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 OPV in routine

immunization globally, while BIVALENT is more commonly used in

supplementary immunization activities.


Types of polioviruses

• 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)

Wild

• Vaccine derived polioviruses (VDPV)• Most are circulating VDPVs (cVDPVs)*• ~49-184 per year since 2008 (through 20 Nov 2013)• Type 2 cVDPVs account for 97% of cVDPVs

VDPVs*

• Vaccine-associated paralytic poliomyelitis (VAPP)**• Estimated ~250-500 globally per year• Type 2 accounts for about 40% of VAPP

VAPP**

† 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.

OP

V

rela

ted

http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx

http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx


What does it mean for the world to be polio-free?

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

Eradication

• Plan refers to wild virus

Endgame

• Plan refers to management of

VDPVs and VAPP


Rationale for continuing use of OPV until Polio Eradication & Global Certification

• 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)

Wild poliovirus still circulating

• 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

Eradication requires OPV

• Inexpensive• Easy to administer• Offers good oral and intestinal immunity—needed for

interruption of person to person transmission

OPV is appropriate for

eradication


Objective 2 of the Plan calls for a phased withdrawal and containment of OPV globally

OPV

wit

hd

raw

al

Remove type 2 by switch from tOPV to bOPV…

Phase 1

2016Type

2

…followed by bOPV withdrawal and cessation of OPV use in 2019-2020

Phase 2

2019-2020All

OPV


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


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.


Risks associated with OPV2 cessation

Two main risks are associated with OPV2 cessation

These risks are mitigated by strengthening routine immunization and

introduction of IPV

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


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

POLIO

OUTBREAK post-

eradication

mOPV1

mOPV2

mOPV3


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


Planned use of IPV: SAGE Recommendations

• Single dose of IPV at 14 weeks of age with 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

• 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

http://www.who.int/wer/2014/wer8901/en/index.html


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


Rationale for introducing at least one dose of IPV prior to the tOPV-bOPV switch

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

Reduce risks

Hasten eradication

Interrupt transmission if

outbreaks occur

IPV

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 introduction

Individual protection against paralytic disease induced by

IPV – REDUCE RISKS

04/19/2023 26

Reduce risks

Hasten eradication


outbreaks occur

IPV

04/19/2023 27

Impact of one dose of IPV*

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

Author year Country ScheduleType 2

SeroconversionIntramuscular administration of 1 dose of IPV

McBean 1988 US 2 mo 35%Simasathien 1994 Thailand 2 mo 39%

Resik 2010 Cuba 6 wk 36%

Mohammed 2010 Oman 2 mo 32%

Resik 2013 Cuba 4 mo 63%

* Estı´variz CF et al. Lancet 2012; 12(2):128-35 IPV introduction


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 weeks or first contact

afterwards, or with DTP3/OPV3 or for countries administering a birth dose of

OPV, at the time of the OPV4 dose

29

Poliovirus type 2 seroconversion & priming

IPV administered at 4 months of age (n=153)

1st dose seroconversion 63%

Priming 98%

1st dose seroconversion & priming 99%

Sutter RW – Presentation to SAGE IPV Working Group June 2013 based on: Resik S et al N Engl J Med 2013;368:416-24

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.

04/19/2023 IPV introduction


IPV Evidence: One IPV dose prevents VAPP in Hungary. Implies priming induces clinical protection.

VA

PP

num

ber

of c

ases

Year

In 1992, single-dose IPV at 3 mos of age,before OPV receipt

In 2006, IPV-only schedule

Sutter RW – Presentation to SAGE IPV Working GroupJune 2013

In contrast, effectiveness against type 1 in Senegal was 36% (0%-67%) implying that seroconversion is the predictor of immunity.

Outbreak control with mOPV2 in a population which previously

received IPV -- REDUCE RISKS

04/19/2023 31

Reduce risks

Hasten eradication


outbreaks occur

IPV


IPV Evidence: What impact is one dose of IPV in routine immunization likely to have during SIAs in outbreak situations?

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 mOPV only in response to an outbreak.IPV-IPV OPV-OPV IPV-OPV

0102030405060708090

100

Figure: Giving a single dose of OPV after a prior dose of IPV gives comparable immunity** to 2 OPV

doses

Type 1 Type 2 Type 3

Comparison of 2-dose response, Faden et al, JID, 1990**These data are based on a US study in Baltimore and Buffalo.

IPV in reducing transmission of polioviruses – Interrupt

Transmission

04/19/2023 33

Reduce risks

Hasten eradication


outbreaks occur

IPV


OPV challenge studies: Shedding of poliovirus in IPV versus OPV vaccinees

From Vidor E et. al, Poliovirus Vaccine – Inactivated, Vaccines 6 th edition, Elsevier, 2013

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.

04/19/2023 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.

From Sutter et al. Poliovirus vaccine-live, Vaccines 6 th ed, Elsevier, 2013 IPV introduction

IPV in boosting immunity in OPV primed individuals –

Hastens Eradication

04/19/2023 36

Reduce risks

Hasten eradication


outbreaks occur

IPV


A single dose of IPV after prior doses of tOPV boosts immunity to types 1 & 3

*Moriniere BJ et al. Lancet 1993;341:1545-50, ** Estı´variz CF et al. Lancet 2012; 12(2):128-35,

• 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**

• 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 tOPV in Ivory Coast but were still seronegative*

3 tOPV + IPV** 3 tOPV + tOPV**

Type 1 seroconversion 80% 40%

Type 3 seroconversion 76% 22%

** Fourth dose at 6 months

Type 2

Type 3

Type 1tOPV: 3 rings of protection against types 1, 2, and 3

mOPV2

bOPV + mOPV2Protection against type 2 provided by

supplementary use of mOPV2 in the setting of an

outbreak

mOPV2

bOPV + IPV + mOPV2bOPV & mOPV2 effect is enhanced in an IPV

population thus facilitating outbreak

control

bOPV+

IPV bOPV + IPVIPV adds protection

against type 2 & boosts immunity to 1 & 3 (enhancing bOPV

effect)Potential Type 2

outbreak requiring mOPV2

bOPV 2 rings of

protection against types 1 and 3

tOPV-bOPV switch

Schematic description of technical rationale for use of at least one dose of IPV

as part of the Endgame Strategy


IPV Presentations and Formulations

• 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

Stand-alone IPV

• Tetravalent, pentavalent, hexavalent available • Combination with whole-cell pertussis not

currently available• Substantially higher cost than stand-alone IPV

Combination products

04/19/2023 40IPV introduction

Example 6-10-14 week schedule with IPV

Vaccine Birth 6 weeks 10 weeks 14 weeks

BCG √

DTP-HepB-Hib √ √ √

Pneumococcal √ √ √

Rotavirus* √ √ √

OPV √ √ √

Stand-alone IPV √ 1st contact after 14 weeks

Single dose of IPV at 14 weeks or 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


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, Pentavalent vaccine, 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)


Multiple Injections: Acceptability and Safety

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.

*http://www.cdc.gov/vaccinesafety/Vaccines/multiplevaccines.html *http://www.cmaj.ca/content/182/18/E843.full

http://www.cdc.gov/vaccinesafety/Vaccines/multiplevaccines.html

http://www.cmaj.ca/content/182/18/E843.full

http://www.cmaj.ca/content/182/18/E843.full


Specific notes on the recommended IPV schedule*

*from 7th Meeting of the SAGE Polio Working Group, October 18-19, 2013

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


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 bOPV will 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

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