Vaccine 22 (2004) 4144–4148

Polio eradication in India: some observations

Yash Paula,∗, Priyab

a A-D-7, Devi Marg, Bani Park, Jaipur 302016, Indiab Department of Paediatrics, Mahatma Gandhi National Institute of Medical Sciences, Jaipur, India

Received 16 October 2003; accepted 7 April 2004

Abstract

In 1988, the World Health Assembly passed resolution WHA 41.28, which committed the World Health Organization (WHO) to the globaleradication of poliomyelitis by the year 2000. In spite of the combined efforts by UNICEF, National Polio Surveillance Project (NPSP), IndianAcademy of Pediatrics (IAP) and Rotary International, Polio Free India is still a distant dream.

Though oral polio vaccine has succeeded in polio eradication from many countries but there is high incidence of vaccine failure in India.O ing 10 orm developingp stered OPVb ses for highi©

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ral polio vaccine (OPV) has failed to provide full protection to many children who have developed paralytic polio even after takore doses of OPV. In some children, OPV has caused paralysis-vaccine associated paralytic polio (VAPP). Number of childrenolio due to vaccine is high and on increase. Reasons for this could be that even immunocompromised children are being adminiecause IPV is not available. Vaccine failure has exaggerated the problem of VAPP. No efforts have been made to find the cau

ncidence of vaccine failure and VAPP.2004 Elsevier Ltd. All rights reserved.

eywords:Paralytic poliomyelitis; Immunization; Vaccine failure; Vaccine associated paralytic poliomyelitis

. Introduction

After eradication of Smallpox, Poliomyelitis was the sec-nd target disease to be eradicated. In 1988, the World Healthssembly passed resolution WHA 41.28, which committed

he World Health Organization (WHO) to the global eradica-ion of poliomyelitis by the year 2000, by providing immu-ization exclusively with oral polio vaccine (OPV).

Dead line for polio eradication had been postponed to thend 2002, but large number of polio cases were reported fromany parts of the country in the latter part of year 2002, andow the dead line for polio eradication has been pushed to

he year 2005.The number of cases of poliomyelitis caused by wild po-

ioviruses in India had declined from 1126 in 1999 to 265n 2000 and 268 in 2001, but there were 1509 cases during002[1]. Later, the number rose to 1600. Poliovirus type 1

∗ Corresponding author. Tel.: +91 141 2314774.E-mail address:dryashpaul2003@yahoo.com (Y. Paul).

accounted for 1404 (93%) cases indicating that it wasan out break, which in the face of intense eradication ewas a severe set back[2].

The objective of the UNICEF, Government of Inthrough the National Polio Surveillance Project (NPSP)Indian Academy of Pediatrics (IAP) and Rotary Internatiowas to eradicate polio from India. Out of the two vacciavailable, namely OPV and IPV, OPV being inexpensiveconvenient because of oral route was logically the righttion.

After concerted efforts by all these agencies for so myears, polio could not be eradicated from India. This isright time that instead of shifting the deadline for eradtion again and again all the concerned agencies invoin the project pause and ponder over the reasons forure to eradicate polio and deliberate upon what needsdone?

An attempt has been made to present an overview reing the polio eradication program, so that appropriate redial steps may be taken to eradicate polio.

264-410X/$ – see front matter © 2004 Elsevier Ltd. All rights reserved.oi:10.1016/j.vaccine.2004.04.032

Y. Paul, Priya / Vaccine 22 (2004) 4144–4148 4145

2. Failure of program

Following are some of the official reasons for failure toeradicate polio by end of year 2000:

1. India started National Immunization Days before devel-oping AFP surveillance.

2. Failure of two-pulse strategy. Two pulse model wasadopted after success in American and Western pacificregions but somehow it did not work in India. (Reasonfor failure had been identified correctly as vaccine failure,but, no steps were taken to find the reasons behind it; evenfour-pulse schedule has failed—authors.)

3. Neglect of routine polio immunization because of pulsepolio immunization.

4. Using only a booth-based approach has not been sufficientto interrupt wild polio virus transmission in the difficultareas where, it is most persistent.

5. Fatigue. Because of in-numerable rounds of Pulse PolioImmunization, volunteers and parents are losing enthusi-asm.

In our opinion, following are some of the plausible reasonsfor failure to eradicate polio by the end of year 2000:

1. Vaccine failure with OPV.2. High incidence of vaccine associated paralytic po-

34

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Center for 1989–1994 period, Ahuja et al. reported that num-ber of children who developed paralytic polio after beingfully immunized with three or more doses of OPV was 14%in 1989 and increased to 22.9% in 1994[12]. An earlier re-port from the same center for 1976 to 1988, had reported anincrease in the proportion of vaccinated children among casesof poliomyelitis[13]. Incidence of paralytic poliomyelitis af-ter vaccination had been reported from other centers also[14,15]. In Rajasthan, number of children who had received6 or more doses of OPV before onset of paralysis was 14/56(25%) in 1999 and 34/58 (58%) in 2000[16,17].

One of the authors had reported low excretion rate of vac-cine polio viruses after administration of OPV, which couldbe due to poor quality of vaccine, presence of immunity inthe children or presence of some inhibitors in the intesti-nal tract of the children[17]. As the number of cases ofparalysis in these children was high it suggests that it couldnot be due to the past immunity, but could be due to poorquality of vaccine and/or presence of some inhibitors in thevaccinees.

Vaccine failure appears to be the main hurdle in eradicationof polio from India. Studies should be undertaken to find thereasons for vaccine failure, so that appropriate remedial stepsmay be taken.

One of the remedial measures for vaccine failure is toa thisi also.U mayb vac-c

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liomyelitis (VAPP).. Lack of hundred percent vaccine coverage.. Non-availability of IPV.

.1. Vaccine failure

Vaccine failure with OPV can occur due to poor qualityaccine or presence of some inhibitors in the gut of the vaee. The quality of OPV can be affected during manufac

ransportation or storage.Response to OPV has been very variable. It was kn

ince long that children in tropical and developing counespond poorly to OPV[3]. By 1967, there had been sotudies showing that the anitbody response of childrePV was apparently lower in hot climates than in coldates[4–6].In Uganda where during early 1970s there was poor s

onversion with OPV, seroconversion rates improved wral horse antiserum was administered along with Ohich neutralized the inhibitors present in children’s sa

7]. On the other hand, Chen et al. had stated: these finuggest that a schedule that relies on three doses of OPhe primary series may provide high levels of immunity fohildren in the United States and that supplementary eo provide additional doses of OPV for selected populate.g. low socio-economic groups) may be unnecessary[8].

.2. Vaccine failure in India

It was Dr. Jacob John who had first pointed out vine failure with OPV[9–11]. In a study from a Sentin

dminister more doses of OPV, but there is a risk thatntervention may increase the number of VAPP casesnvaccinated and vaccinated but non-immune childrene at a higher risk from these mutant and neurovirulentine poliovirus strains.

.3. Vaccine associated paralytic poliomyelitis—VAPP

“No remedial intervention of any sort is absolutely riree. Even the commonest drug may carry some degree oo a fairly large number of users, and a possibly life threang risk to an exceedingly small number of persons whoypersensitive to it. Any public health or medical judgmust be made on the basis of balancing the values anroblems of one procedure against those of another procnd against the risk of doing nothing at all. . .. Epidemiolog

cal data obtained in the USA and elsewhere indicate thanstances in which the live vaccine virus has reverted toovirulence and attacked vaccinees or their close contacxceedingly rare. Recently in the USA, new discussionsrguments have arisen from proposals that killed vaccine-established for general use in that country. The arguor killed vaccine has included reference to the “dangershe live vaccine. Because of unfortunate distortions byews media and their possible effects on public reactioould like to re-emphasize what has repeatedly been sy many different national and international groups oferts: a vaccine that in the USA produces at most, oneer 11.5 million vaccinees (and one case per 3–9 miontacts), is far from “dangerous” but rather is outstandiafe, as well as effective”[3].

4146 Y. Paul, Priya / Vaccine 22 (2004) 4144–4148

Should there be any reasons for concern regarding VAPPin our country after reading the above mentioned statement?There are three good reasons for concern:

(i) The above statement was published in 1978; in 1997schedule of two doses of IPV followed by two doses ofOPV was introduced in the United States. This inter-vention brought down the incidence of VAPP from 8 to10 cases per year to one case in 1998. Even this numberwas not acceptable and since January 2000, it has beenchanged to all IPV schedule.

(ii) High incidence of vaccine failure in India.(iii) Response to any illness or vaccine may vary from person

to person, region to region.

“In the participating countries, in which more than 191million doses of vaccine were given during the period underreview, there remained 205 cases that had at least a possibleassociation with live poliomyelitis vaccine. . .. There wereconsiderable differences from one country to another. Twocountries had no recipient cases, and in others the rates inrecipients per million doses distributed were: 0.087, 0.208,0.314, 0.390, 1.379 and 2.288”[3]. Thus, the argument thatin the USA incidence of VAPP was so rare, so same shouldbe in India may not be valid.

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3. Resistance to OPV administration

There is a resistance to OPV administration by some par-ents and this is on increase, which could be due to some ofthe following reasons.

3.1. OPV and infertility

Fear in some sections of the society that OPV adminis-tered during childhood may lead to infertility in later life.These fears are baseless and unscientific. Origin of theseviews could be because of ignorance and/or malicious mo-tives.

3.2. Apathy by the parents

For the last many years, Pulse Polio Immunization is be-ing conducted with the message: ‘give two drops of vaccineto your child and assure life long protection to your childagainst polio’. In-numerable rounds of Pulse Polio Immu-nization have taken place with the added message that thechildren must be administered OPV in this round also evenif they had received many doses of OPV in past. It is naturalfor the parents to be wary and suspicious that either the au-thorities themselves do not know how many doses of vaccinea area anyr

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.4. Enormity of problems

.4.1. High numberIn a study one of the authors had reported that there

fteen AFP cases from Rajasthan during the year 2000,ould be labelled as VAPP cases. One was virologicallyrmed case, while 14 were compatible VAPP cases[17].

According to NPSP there were 181 and 182 VAPP cn India during 1999 and 2000, respectively. AFP casesevelop asymmetric paralysis 4–40 days after taking Oaralysis persists beyond 60 days and wild polioviruseot detected in stool samples are considered VAPP cut, NPSP had excluded all such cases. AFP Surveillanone for children upto 15 years of age, so the individbove 15 years who had developed contact VAPP wernown to NPSP. The expected number of VAPP cases0–75 per year. Because of non-availability of IPV, immuompromised children are being administered OPV. RisAPP in immunocompromised children is 2000 times higs compared to immunocompetent children.

.4.2. VAPP after subsequent doseIt is reported that VAPP occurs mostly after first dos

PV; in Rajasthan VAPP has reportedly occurred mostler subsequent doses[16,17], because of vaccine failure. Aording to a study by Kohler et al. there were 181 VAPP cn 1999; 121 contact cases and 60 recipient cases. Outecipient cases 9 had developed VAPP after first OPVnd 51 developed VAPP after subsequent OPV dose[18].umber of contact VAPP cases being more than reciAPP cases should be a reason for serious concern.

,

re required to provide protection to the children, or theyware of the fact that the vaccine is ineffective and so, mounds of vaccination are being conducted.

.3. OPV during illness

During PPI rounds some times even very sick childre administered OPV. When any seriously ill child, whoeen administered OPV during PPI round dies, the dearroneously attributed to OPV by the parents, which hegative impact on the campaign.

.4. Vaccine failure and VAPP

The parents are aware of two facts: (i) many children heveloped polio even after taking many doses of vaccin

heir neighborhood and (ii) some children in their neighood have developed polio after taking the vaccine.

. Resistance to introduction of IPV

Following are some of the reasons that IPV is not bntroduced in India.

.1. IPV is expensive

Many children have developed polio even after takore than 10 doses of OPV after in-numerable rouf PPI, so the issue of cost of vaccine becomes irant. Varicella vaccine and Hepatitis A vaccine are m

Y. Paul, Priya / Vaccine 22 (2004) 4144–4148 4147

times costlier than IPV. Recently, DPT with acellularpertussis component has been introduced in the Indian mar-ket, it is a very expensive vaccine. With-holding the in-troduction of IPV even for immunocompromised childrenand making other costlier vaccines available cannot bejustified.

4.2. Trained personnel would be needed to administerIPV as it is injectable

IAP and Ministry of Health, Government of India conve-niently overlook three facts:

(a) Five doses of DPT vaccine are being administered to chil-dren upto 5 years of age. Four doses of IPV are needed,three doses during primary immunization and one boosterdose during second year of life. DPT and IPV can be givenas a combination vaccine also.

(b) IAP has been advocating inclusion of hepatitis B (HB)vaccine in the National Universal Immunization Pro-gram. IPV would be required initially for about 120–130million under five children, and subsequently for 40–50million children every year. HB vaccine would be re-quired initially for about 1000 million persons and sub-sequently for 20–30 million children every year but, willhave to be continued for the next 40 years or so. No

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polioviruses because of improvement in hygiene and sanita-tion.

There is an urgent need for serological studies to findwhether the children are developing seroprotection after vac-cination or not. The serological studies are required for onemore reason also, because of sanitation and hygienic livingconditions being introduced in some sections of the popula-tion. Improved sanitation and hygiene reduce the opportuni-ties for natural infection. In pre-vaccine era, children fromaffluent families with better sanitation and hygiene did notdevelop immunity against polioviruses because of lack ofexposure to wild polioviruses, whereas children from ar-eas with poor sanitation and hygiene had chances of en-countering natural infection and more children developedimmunity against polioviruses. At the time of polio out-breaks during that period, more children from better socio-economic families were reported to succumb to paralyticpolio.

Since introduction of Universal Immunization and PulsePolio Immunization, it has been observed that now morecases of paralytic polio are being reported from rural andurban slum areas as compared to the children from ‘cleanareas’. This difference in the incidence of polio may be be-cause with improved sanitation and hygiene, chances of ex-posure to natural infection are reduced. Serological studieso eas’a mu-n duet be-c ction,t e ofp bet-t dis-e omics

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constraint of trained personnel appears to exist forvaccination.

c) Hazards of injectable vaccines. In a joint publicatioUNICEF and IAP entitled ‘Together we make India pofree’, on page 7 it is stated: “The sole advantage ofis that it carries no risk of VAPP. The disadvantagesthat it must be administered by medically trained pernel, it is much more expensive (Rs. 450 per dose),less effective at interrupting spread of virus, and itries with it all the complications of injection”. All succomplications of injection with hepatitis B vaccineconveniently overlooked.

In 1999, Dr. Jacob John had stated: “Yash Paul is rigemanding that IPV be made available for individual ushildren in whom OPV is contra indicated”[19]. On 9 June000, one of the authors had written to Dr. Sobhan Sarkaistant Commissioner, Immunization, Ministry of Healthamily Welfare, New Delhi; with a copy to Hon. Secreteneral, Indian Academy of Pediatrics, Mumbai, stating

PV be made available for high risk population, on paymike other vaccines[20].

. Serological studies

Incidence of polio has come down appreciably duringineties of the last century. There have been three contrib

actors in bringing down the number of polio cases: (i) paccine, (ii) natural immunity imparted by wild poliovirusirculating in the community, and (iii) less exposure to w

nly can demonstrate whether children from ‘clean arre getting paralytic polio in less number because of imization, or due to less exposure to natural infection, or

o both. If this phenomenon of differential incidence isause of less exposure only, and not due to seroprotehen it could prove dangerous in the long run. In casolio outbreaks in future, then more children from this

er section of population would succumb to paralyticase as compared to the children from poor socio-econection.

Thus, serological studies should be undertaken to evahe immunological status of the vaccinated children. Ifspect of polio eradication is neglected now, then the chiay have to pay a heavy price later.

. Conclusions

Polio cannot be eradicated by the present polio eradicrogram, as polio cases will continue to occur because oine failure and VAPP. Due to some unknown reasonss a high incidence of vaccine failure with OPV, which hasulted in higher incidence of polio cases by wild polioviruven after taking many doses of OPV and VAPP becauutant neurovirulent vaccine viruses. Studies should bertaken immediately to find the causes for vaccine fao that appropriate remedial steps may be taken. Simfforts should be made to reduce the incidence of VAPP.hould be made available immediately for those who nepecifically, for example, immunocompromised childrehose who have immunocompromised family members.

4148 Y. Paul, Priya / Vaccine 22 (2004) 4144–4148

Funding: none

Competing interest: none.

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[2] John TJ, Thacker N, Deshpande JM. Setback in polio eradi-cation in India in 2002: reasons and remedies. Indian Pediatr2003;40:195–203.

[3] Melnick JL. Advantages and disadvantages of killed and live po-liomyelitis vaccine. Bull WHO 1978;56:21–38.

[4] Lee LH, Wenner HA, Rosen L. Prevention of poliomyelitis in Sin-gapore by live vaccine. BMJ 1964;1:1077–80.

[5] Poliomyelitis Commission, Western Region Ministry of Health,Nigeria. Poliomyelitis vaccination in Ibadan, Nigeria during 1964with oral vaccine. Bull WHO 1966;34:865–76.

[6] Drozodov SG, Cockburn WC. The state of poliomyelitis in theworld. In: Proceedings of the 1st International Conference on Vac-cines against Viral and Rickettsial Diseases of Man. Washington,DC: Pan American Health Organization; 1969. p. 198–209.

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[8] Chen RT, Hausinger S, Dajani AS, Hanfling M, Baughman AL,et al. Seroprevalence of antibody against poliovirus in inner-citypreschool children. JAMA 1996;275:1639–45.

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[10] John TJ, Jayabal P. Oral polio vaccination of children in the tropics1. The poor seroconversion rates and the absence of viral interfer-ence. Am J Epidemiol 1972;96:263–9.

[11] John TJ. Antibody response of infants in tropics to five doses oforal poliovaccine. BMJ 1976;1:811–2.

[12] Ahuja B, Gupta VK, Tyagi A. Paralytic Poliomyelitis (1989–1994):report from a Sentinel Center. Indian Pediatr 1996;33:739–45.

[13] Sharma M, Sen S, Ahuja B, Dhamija K. Paralytic poliomyeli-tis 1976–1988: report from a Sentinel Center. Indian Pediatr1990;27:143–50.

[14] Chaturvedi P, Bannerjee KS, Bharambe MS. Acute paralytic po-liomyelitis in rural Maharashtra. Indian Pediatr 1992;29:777–9.

[15] Soudarssaname MB, Rotti SB, Srinivasa DK, Ramalingam G. Par-alytic poliomyelitis in children under 6 years in Pondicherry: acommunity survey. J Epidemiol Commun Health 1993;47:210–4.

[16] Paul Y, Thacker N. Polio eradication strategy: need for re-appraisal(reply). Indian Pediatr 2000;37:1396–400.

[17] Paul Y. Accuracy of the National Polio Surveillance Project Datain Rajasthan. Indian J Pediatr 2002;69:667–73.

[18] Kohler KA, Banerjee K, Hlady WG, Andrus JK, Sutter RW. Vac-cine associated paralytic poliomyelitis in India during 1999: de-creased risk despite massive use of oral polio vaccine. Bull WHO2002;80:210–6.

[19] Paul Y, John TJ. Contraindications of OPV. Indian Pediatr1999;36:318–20.

[20] Paul Y. Polio eradication strategy. Need for re-appraisal. Indian Pe-diatr 2000;37:913–6.