- There has been an alarming increase in the number of cases of AFP (acute flaccid paralysis) in the country since 2003 – from 8505 to 27,050 (figures from http://www.npspindia.org). As against an international average of 1/100,000, the national average is 6.3/100,000, and even higher in case of the endemic states of UP and Bihar, with 12-13/100,000.
- Immunized children form a significant proportion of the children with confirmed wild poliovirus in the post-GPEI period. As per WHO data (cited in Sathyamala et al 2005), except for the outbreak in 2002, between 2000 and 2003, more than 50 per cent of the children with paralysis due to wild poliovirus, both confirmed and compatible, had received more than three doses of OPV. Similar findings have been reported also in the pre-GPEI period (John 2004).
- It is clear that there is an alarmingly high incidence of vaccine associated paralytic polio cases (VAPP) in the country, though the NPSP has refrained from the publishing the number of VAPP cases. The number of “vaccine virus cases” has more than tripled between 2002-2005, from 500 to 1645 in 2005.
- The Pulse Polio Programme has adversely affected the functioning of the already declining public health care system in India. Immunization coverage has decreased between 188 to 2003, from 54 per cent to 48 per cent, as shown by the District Level Household Survey 2002-2004.
- There is a gross mismatch between public health needs and actual resource allocations. For instance: the 2006-2007 health budget of the central government has the following provisions:
Pulse polio- Rs 1004 crores; All routine immunizations – Rs 327 crores; TB control – Rs 184 crores.
When compared with their prevalence and mortality – about 1.5 crore TB cases and 4 lakh annual deaths due to TB, as compared to estimated 20,000 polio cases and less than 500 deaths when the polio eradication programme was launched in 1995, it points to complete mismatch between national need and choice of priority.
In addition we would like to point out that:
1. For every clinical case of paralytic polio, there are about 100-1000 sub-clinical cases (GoI 2000), which too allow the virus to replicate. Hence even if there is no case of paralytic polio, the wild virus will continue to circulate and replicate because of the pool of sub-clinical infections. Moreover, it is impossible to ensure 100 % sero-conversion even if we ensure 100 % coverage, which means that there will always be a pool of sub-clinical infection even if overt paralysis does not occur.
2. The majority of the oral vaccine viruses given to children revert to the virulent form within a month (WHO 1958; Melnick et al 1967; Guillot et al 1994). Hence, though OPV reduces the incidence of paralytic polio, it adds to the pool of virulent polioviruses. Hence, vaccination with OPV cannot be discontinued even if the incidence of paralytic polio is reduced to zero. The aim of cessation of vaccination was the reason why the eradication programme was launched in the first place.
3. There have been changes in the definition of polio case between the pre-GPEI and post-GPEI period, from clinical classification to virologic classification of AFP cases. In addition, there have been changes in the wild polio virus classification scheme also. The dramatic reduction in polio cases from 1994 to 2005 can thus be attributed in large measure to this change in definition (Sathyamala et al 2005).
John, J.T. (2004) End-stage challenges: Vaccine associated paralytic poliomyelitis. Bulletin of the World Health Organisation, 82 (1).
Sathyamala, C., Mittal, O., Dasgupta, R., and Ritu Priya (2005) Polio Eradication Initiative in India: Deconstructing the GPEI. International Journal of Health Services, 35(2), 361-383.
Government of India (2000) Child Health Division, Department of Family Welfare, Surveillance of Acute Flaccid Paralysis, Field Guide, Ed.2, New Delhi.
WHO-TRS (1958) No. 145: Expert Committee on Poliomyelitis.
Melnick et al (1967) Studies of the immunogenicity , communicability and genetic stabiliy of oral polio vaccine administered during winter. American Journal of Epidemiology, 86, 112-135.
Guillot et al (1994) Point Mutations Involved in the Attenuation/Neuro-virulence Alternation in Type 1 and 2 Oral Polio Vaccine Strains Detected by site specific polymerase chain reaction. Vaccine, 12(6), 503.