Lessons Learnt From Polio Eradication in India & Future

Prospects

Dr. Jishnu Sathees LaluDep of Community Medicine

AIMS,Kochi

Contents• Introduction • History • Epidemiology of polio virus• Polio Eradication in India• Lessons learnt from polio eradication

in India• Future prospects• conclusion

Introduction • Polio was hyper endemic in India

with 2-4 lakhs cases annually.

• One in 200 infections leads to irreversible paralysis.

• The world is on the verge of achieving WPV eradication.

History • The oldest and clearly identifiable

reference of polio is an Egyptian stele which is more than 3000 years old

• Till 1952 epidemic outbreaks were being reported annually.

Epidemiology

Agent • Enterovirus subgroup- Picarnoviridae

family• Inhabitants of the GI tract• 3 serotypes polio virus• IP-7 to 14 days• Transmission is possible as long as

the virus is shed. Highly infectious in the absence of immunization.

Reservoir • Man is the only known reservoir of

infection.

• Fecal oral route transmission, oral – oral transmission is also possible.

Clinical features• Upto 72% of all infections in children are

asymptomatic- sheds virus in stools• 24% Low grade fever,sore throat with out

CNS invasion- abortive polyomyelitis• Fewer than 1 % of all polio cases results

in flaccid paralysis.• Many patients with paralytic

poliomyelitis recover completely. Weakness or paralysis present for >12 weeks will stay permanent.

Types of paralytic polio• Spinal polio- most common,

asymptomatic paralysis often involving the legs.

• Bulbar polio- leads to weakness of muscles innervated by cranial nerves.

• Spinobulbar polio- a combination of both(19%)

Lab testing• Virus isolation: from stools and

rarely from CSF or Blood.

• RT-PCR or Genomic sequencing - for distinguishing from “wild type” or “vaccine type”

Vaccines • No treatment

• Can be prevented through effective vaccination.

• First vaccine Salk vaccine in 1955

• Trivalent Sabin vaccine in 1961

IPV OPV• Consists of

formalin inactivated whole virions of all 3 serotypes poliovirus

• Contains live attenuated Polio virus 1,2 and 3.

VAPP ,VDPV& cVDPV• VAPP- Paralytic disease occurring in

vaccine recipients, or contacts of recipients immunized with OPV

• VDPV-Vaccine virus genitally reversed to neurovirulent Virus known as VDPV and transmitting to unvaccinated children causing polio outbreaks.

• cVDPV- If one genotype of VDPV is detected in two or more children with polio.

WHO South East Asian Region [SEAR]

1. Bangladesh 2. Bhutan 3. Democratic People's R

epublic of Korea

4. India 5. Indonesia 6. Maldives 7. Myanmar 8. Nepal 9. Sri Lanka 10. Thailand 11. Timor-Leste

SEAR certified on

27 March ‘14

Total cases WPV cVDPV

Globally 27 0

in endemic countries 27 0

in non-endemic countries 0 0

Global polio status

24

Total =273 Endemic countries

PakistanAfghanistanNigeria

3

Pre eradication Era

1 Hyper endemic India

2 EPI in India

3 GPEI

Hyper endemic polio era• Incidence in India were the highest

reported anywhere (2 – 4 lakhs cases).

• Post independence India targeted diseases like TB , Malaria, Leprosy and Kala azar but not poliomyelitis.

• Inspite of the availability of IPV in 1955,OPV was imported in 1962.

EPI era • EPI was launched to protect from 6

vaccine preventable disease.

• Achieve a vaccination coverage of >80%

• India began the attempt to control polio by immunization only in 1978 .

• WHO launched EPI in 1974.

Introduction of OPV didn’t cause any decline in cases.

Factors lead to EPI failure

1. Coverage of 80% vaccination was achieved slowly

2. Low vaccine efficacy

3. Provocation poliomyelitis

Recommendations to improve Vaccine Efficacy

• At least 5 dose polio immunization

• Giving the doses in pulse fashion

• IPV given intra dermaly in fractionated doses

• Later ,> 80 % 3 dose OPV coverage-result in improved vaccine efficacy and indirect herd effect.

GPEI Phase• 1988, WHA – target polio for global eradication

by 2000.(125 countries endemic)1. maintaining high coverage of vaccination

with at least three doses of live oral polio vaccine (OPV),

2. providing supplemental rounds of vaccination3. establishing an effective mechanism for the

surveillance of acute flaccid paralysis (AFP)4. house-to-house OPV “mop-up” campaigns

carried out at the final stage in a limited geographical region.

• Polio burden had not reached control status in India

• Polio cases were estimated to be > 22 lakhs from 1980 through 1990.

• To certify as polio free in 2000,India should report zero case by 1997.

Factors lead to the burden

• Serious under reporting of cases continued.

• EPI could only deliver vaccine ,not measure or monitor the disease burden.

• GOI relayed on EPI to achieve the target even after data showed the national policy was faulty.

Era of Eradication

1 1995- 2000

2 2000-2005

3 2005 to Rukhsar

1995- 2000

• India’s effort to implement polio eradication started only in 1995 targeting eradication by 2000.

• PPI of children under 5 years at fixed booths on 2 National Immunization days, separated by six weeks during the winter months.

• WHO,UNICEF,CDC and Rotary International designed a modus operandi for India

• Launches the NPSP in 1997,a collaboration of WHO and GOI.

Lessons from EPI failure1. Failure to vaccinate

2. Failure of vaccination

3. Lack of nation wide surveillance

Failure to vaccinate• Nation wide PPI campaigns 1995-1999, WPV2 stopped

circulating by 1999 October.

• In 1999,India was divided into high, medium and low risk states.

• Sub-national vaccination rounds were conducted in high and middle risk states.

• In order to improve the coverage of vaccination House to house immunization was started in 1999 to actively search and vaccinate missed children.

NPSP• Founded in 1997- the heart of India’s

polio eradication• Active surveillance of AFP cases in

the entire country.• IEAG revised quality of AFP

surveillance to at least 2/100,000.• Unfortunately, even as >10/100,000

were reported.

Did we miss the target?

Achievements • Nation wide PPI campaigns stopped the

transmission of WPV2 by October 1999. last case was in Aligarh, Uttar pradesh.

• WPV circulation was limited essentially to the two Northern states of Bihar and UP.

• India declared 2005 as the target year for polio eradication in the National Health policy.

New tactics for 2005

NPSP• Adopted a ‘Virological scheme’ in place of

clinical classification of AFP cases.

• Environmental sewage specimen testing started in 2001.

• Expanded its network with more than 200 SMO.

• Increased sensitivity- the program soon became able to detect any poliovirus transmission anywhere in the country.

Virologic Classification Scheme

AFP

Wild Poliovirus Confirm

Inadequate Stool Specimens

No Wild Poliovirus2 Adequate Stool

Specimens

No Residual Weakness

Residual Weakness, Died or Lost to f/u

Expert Review Discard

(Non-Polio AFP)

Compatible

Discard(Non-Polio AFP)

Discard(Non-Polio AFP)

Immunization • House to house vaccination strategies

were strengthened

• Identification of missed children- the little finger of the left hand was marked with indelible ink.

• Transit vaccination- teams stationed at bus stands, railways stations, highways etc.

Social mobilization • Social mobilization network was

launched in UP and Bihar- to generate community support for polio immunization.

• Convergence-to generate acceptance among the community

• Under served strategy- targeting poor Muslim communities.

Social mobilizing Network

• Launched in 2001 to generate community support.

• Community mobilizers work with local medical practitioners, religious leaders, school teachers and others to influence local people in support of vaccination.

• Mobilized communities house by house to accept OPV and other health interventions.

• Celebrities like Amitabh Bachan as brand ambassador of UNICEF motivated leaders and community for greater progress.

• The mass following of the celebrity and his endorsement of the polio programme is widely recognized as being a key generator of community support for polio vaccination.

CONVERGENCE • In addition to providing information

about OPV, the Social mobilizing network shares information on

1. EPI2. exclusive breast feeding3. the use of ORS and Zinc to tackle

diarrhea etc.4. Sanitation and hygiene

Under served strategy• A special strategy to reach the under

served Muslim communities.

• To tackle the disproportionately high percentage of polio cases.

• Developed partnership with key muslim leaders and institutions- for polio acceptance

Why Bihar and UP were high risk states?

• Even after several PPI and Subnational rounds WPV transmission couldn’t be interrupted .>85% of the cases were reported from these two states.

• 60% of WPV cases from the Muslim community.

• 32% cases of Non-Polio AFP had received 3 or less tOPV doses

How did we target them?• Social mobilization was first launched in UP

and later in Bihar in 2003.

• Underserved strategy

• Ulemas committee- engaged key religious leaders to get community support for polio eradication.

• Local level microplaning

• Expanded the no. of AFP reporting units

Did we miss 2005 target too?

• 66 cases were reported in 2005.

• The virus strayed into other states as far south as Karnataka, kerala and Tamil nadu.

Achievements 1. A sensitive surveillance system to identify

any case of poliovirus transmission across the country.

2. The under-served strategy improved the vaccine acceptance in the marginalized sections of the society.

3. Transit vaccination and house to house immunization improved the coverage >95%

What was lacking ?• Failure to vaccinate both under EPI schedule

and in Pulse campaigns.(Bihar-27%,Western UP-38% and Eastern UP- 45%)

• ‘Failure of vaccine’- the extremely poor efficacy of OPV permitted WPV transmission in western UP and in Bihar.

• Persistent transmission attributed to failure of vaccine and very high FOT of WPV due to the very high density of infant population.

2005 to Rukhsar

Vaccine and vaccination changes

• Monovalent vaccine against WPV 1 and WPV 3 were introduced.

• To counter vaccine failure and failure to vaccinate, the number of PPI campaigns was increased to 10 each year from 2005 and the under-served and transit vaccination strategies were sustained.

• In 2006 outbreak-638 cases of WPV1 and 28cases of WPV3

• Population immunity gap was found <2 yrs children, due to poor UIP coverage with tOPV and less opportunities to receive mOPV1 in Pulse campaigns.

• Migrant strategy: reach out to the most vulnerable migrant population in brick kilns, construction sites and nomadic sites

New born tracking• introduced in 2006- to identify, track

and immunize every new born child in the highest risk area of UP and Bihar.

• Each child in this vulnerable area will receive at least 8 rounds of OPV before the age of 1 year through UIP and PPI campaigns.

Targeting WPV1 WPV3• India in 2006 prioritized elimination of

WPV1 – >90 % of polio cases in the country and the agent of re infection of a few polio free countries and states were WPV1.

• SIA campaigns used mOPV1 and mOPV3.

• IEAG planned sequential elimination of WPV1 first and WPV3 later.

Kosi river area intensification.

• Difficult to access area • Satellite offices and over night stay

points were set up to reach areas were children were being missed.

Strategy against 107 blocks

• Conducted additonal mOPV3 SIA rounds while continuing to use m OPV1 for most SIA.

• Multi pronged strategy to address polio associated risk factors with rapid improvement in sanitation and hygiene,availablity of clean water, exclusive breast feeding and the prevention and control of diarrhea.

• By 2009 WPV1 had virtually disappeared but due to less use of mOPV3 and poor UIP coverage of tOPV, WPV3 outbreaks continued to report.

• bOPV was recommended instead of mOPV3 to address both WPV1 and WPV3.

Results • WPV1 recorded lowest numbers in

subsequent years and finally its transmission ceased in January 2011.

Rukhsaar khatoon ,Jan 13 2011

Certification of polio eradication

• The national certification committee

• Regional Certification committee

• Global certification committee

Lessons learnt

1. Political will and technical leadership

2. Vaccination with a high efficacy vaccine

3. Disease surveillance and immunization progress monitoring

4. Mobilizing social and community support for vaccination.

Political will and technical leadership

• India could have achieved eradication decades ago even before the launch of EPI in 1974.

• Application of the scientific knowledge about the vaccine and vaccination was neglected by the government.

• Lack of a public health department with technical leadership only caused financial burden.

Vaccination with a high efficacy vaccine

• tOPV had less type 1 and 3 efficacy.• IPV was proven to highly efficacious and

many countries eradicated polio using nation wide vaccination with IPV.

• SIA rounds with monovalent OPV against type 1 and 3 drastically reduced the transmission of WPV1 and WPV3.

• Later SIA included bOPV and curtailed all WPV 1 and 3 cases.

Tactics for Immunization coverage

• House to house vaccination• Identification of missed children• Transit site vaccination• Congregation site vaccination• New born tracking• Immunization along the international

borders • Responding to polio as a public health

emergency

Disease Surveillance for immunization progress monitoring • Polio case identification- using virological scheme

• Reporting network expansion- a large network of health facilities over 33,700sites, including public and private health facilities.

• Increase in sensitivity of AFP surveillance- by broadening the definition of AFP cases to make surveillance more sensitive for AFP cases.

• Sewage sample testing

• Change in laboratory test surveillance- a new methodology of testing the stools was introduced which takes only 2 weeks of time compared to 5 weeks earlier.

Social mobilization as a key to eradication

• Social mobilization network

• Migrant strategy

• Under served strategy

• Brand ambassadors and celebrities

Delay in achievement• Lack of technical leadership at

central and state level

• Use of less efficient OPV

• Absence of disease surveillance and laboratory support services

• Any eradication program should be started with sufficient funds and financial backup from donors.

• eradication should always be targeted to a shorter and stipulated time frame, as a long duration leads to fatigue and decreases the performance of the people involved

Future prospects

• Immunization across the international borders and OPV vaccine certification to travel to endemic countries.

• True polio eradication = zero transmission of WPV + Vaccine polioviruses.

• Ethically unacceptable to use OPV after eradication- vaccine virus-genetic reversal to neurovirulence

• cVDPV – interrupted using IPV.

• Elimination of VDPV using IPV- phase 2 polio eradication

Risk factors of emergence of VDPV-

1. Gaps in population immunity 2. continued use of OPV.

• Introduce IPV in UIP- withdraw OPV after achieving high coverage for IPV.

• AFP surveillance and virological investigation of every child with AFP -continued for three consecutive years following withdrawal of OPV.

POLIO ERADICATION END GAME STRATEGY

• WHO announced the steps to complete and conclude polio eradication in 2012.

1. Universal introduction of IPV

2. tOPV to bOPV switch

Cost and feasibility • OPV: Rs:4 per dose• IPV: Rs:80 – 250 per dose

• To reduce overall cost of Imported IPV

1. 2+1 schedule can be used2. Intradermal injections in

fractionated doses

Future concerns• Re emergence of Polio in the post

eradication phase is anticipated.

• Cessation of OPV

• IPV manufacturing using WPV post eradication pose some risk of inadvertent leak.

• Importation of WPV /VDPV

CONCLUSION

THANK YOU

References • Eradicating poliomyelitis:India’s journey from

hyperendemic to polio free status-T jacob john• Polio programme: let us declare victory and move

on- Neetu Vasisht• Global polio eradication initiative: lessons learned

and legacy- Stephan L Cochi• The journey to a polio free India:UNICEF• Polio eradication and end game strategic plan:GPEI• Polio eradication in India:Getting to the verge and

beyond:Centre for strategic and International studies