Letters to the Editor
Indian Pediatrics 2003; 40:1102-1104
I appreciate Dr. Srivastava’s comments and
there are no questions that demand my response.
I agree with Dr. Gupta that the Academy could benefit from introspection of how it failed to effectively respond in the past to clinical vaccine failure of the 3-dose schedule of OPV and the sub-optimal antibody response in children, as well as the potential for the alternate vaccine, namely IPV.
Dr. Gupta is convinced of the need for IPV but he is concerned about the cost involved. If the evidence and rationale are convincing, then we should present them to the Government and leave the economic issues to the experts of that field. One of the important advantages of IPV is that it can be used as a combination vaccine with DPT, thereby nulli-fying costs now incurred for transportation and storage of OPV and avoiding multiple contacts with children. The Government should ask the industry to examine how much it would cost to manufacture and sell, with the assured market for 25 million birth cohorts. Only with these steps behind us can the Government arrive at a probable budget to see if it really exceeds that of the current expenditure for the large number of OPV doses and contacts, and if it does, by what margin. If manufactured indigenously, IPV may become a foreign exchange earner and strengthen our national economy rather than weaken it. India is by far the largest supplier of measles vaccine globally, earning considerable foreign exchange, and history could repeat with IPV also.
Dr. Gupta has pointed out that there were 81 cases of wild virus polio till May 24 "and still higher numbers expected in next 3-4 months". But then, there is also the probability of markedly reduced circulation of wild viruses in the coming months on account of the combined effects of the outbreak in 2002-2003, the additional pulse immunization (sub-national immunization days, SNID) in April and June in the affected States, mop up campaigns wherever wild virus is imported, and, the awareness of the poor performance of routine coverage and some remedial action already being taken. As I write this reply on July 6, the total tally of wild-virus-polio cases so far in May is only 5, of which only two are in UP. Even though this may not be the final number, it is going to be the lowest ever for the month of May and it is still possible to hope for interruption of transmission in 2003 itself. If interruption of transmission is delayed, then each milestone will be delayed that much, as already stated in my paper.
The setback in 2002 was an eye-opener for many, especially regarding the "behavioral barriers" mentioned by Dr. Gupta. However, to describe the situation as "lack of consumer participation" is an overstatement. There has been dissatisfaction and some non-cooperation on the part of a minority of parents, but tactics to overcome these are already being applied. There are only two annual national pulse campaigns or immunization days (NIDs), contrary to his worry of "frequent" NIDs. In the States highly endemic for polio in 2002, additional SNIDs were designed mainly because routine coverages are low and are unlikely to pick up to high levels by mid 2003. Infants born prior to 2003 would have been infected and immunized by type 1 and 3 polioviruses during the outbreak in 2002. But infants born subsequently need to be covered and the April and June SNIDs would have acted partly in lieu of the deficient routine coverage and partly as a deterrant against wide circulation of wild viruses. The same logic applies to the proposed SNIDs of September and November 2003, prior to the next rounds of NIDs. Had the routine immunization coverage been high like in many other States, these additional pulsing would not have been needed.
Dr. Paul uses the context of commenting on my paper as a pretext to roundly criticize the Polio Eradication Committee of IAP, the National Polio Eradication Program, the criteria of diagnosis of polio for the purpose of eradication and the immunization strategy for eradication. Much of his reproach is based on incomplete reading of the original paper, inadequate understanding of facts, inappropriate focus on irrelevant issues, and ignorance of published papers pertaining to the subject, compounded by pervasive pessimism. He attributes the first key message in my paper to the ‘Members of the Polio Eradication Committee’, indicating that he has confused it with another paper in March issue of Indian Pediatrics, co-authored by myself and the Convener of the Committee. On behalf of the Committee I can categorically state that we are fully aware of the case classification criteria and their field application, as well as the problem of vaccine failure. The Committee has not overlooked them as alleged by him.
Dr. Paul disagrees with my assessment that the "failure to eradicate wild viruses is due to inadequate vaccine coverage" and that "honest implementation of intensive immunization, both routine and pulse, using OPV, will eliminate wild polioviruses". He has no factual support for his opinion. Andhra Pradesh, Kerala and Tamil Nadu provide ample evidence for my stand, as the interruption of wild-virus transmission was achieved there only through immunization. Contrary to Dr. Paul’s allegation, I have not prophesied that wild virus transmission will be stopped in 2003 and eradication will be certified in 2006. What I have said was "In all probability we may achieve the elimination of circulation of wild viruses in India within a short time, perhaps in 2003 itself", and "There is hope for interrupting wild virus transmission in 2003".
I have presented arguments as to how and why VAPP could and should be eliminated, as early as feasible. In his three points of advice to the IAP Committee the second is to "Introduce IPV on selective basis with immediate effect to reduce the incidence of VAPP". Scientifically speaking, such introduction of IPV on a limited basis will not be sufficient to reduce the incidence of VAPP. Only large-scale use of IPV will reduce the incidence. Programmatically speaking, the Committee or IAP has no powers to introduce it, as it is an unlicensed vaccine in India. So, both ways this advice is meaningless. Dr Paul’s statement, "VAPP can be eliminated by stopping OPV altogether and starting IPV" is highly irresponsible. Such action will have disastrous consequences. As I have elaborated in my paper, OPV cannot be stopped and IPV introduced; the sequence is wrong. IPV must be introduced systematically, high coverage achieved and then only the withdrawal of OPV can begin.
Dr. Paul says, "some AFP cases had been discarded as non-polio cases even without 60 days follow up because stool samples were negative for wild polioviruses". In the current virological classification of cases, reliance is on tests conducted on adequate stool samples collected in time. As pediatricians we know that 60-day residual paralysis is neither sensitive nor specific for polio. The focus is not on a syndrome of AFP with residual paralysis, but on AFP caused specifically by poliovirus.
According to Dr. Paul, the success of eradication "depends on the answer to the question: ...has any child developed polio after taking age appropriate number of OPV doses?" If the answer is yes, he would want us to believe that the "program in its present form" cannot eradicate polio. Of course the answer is yes. The fact of the matter is that eradication is the answer to this problem.
I disagree with Dr. Paul’s audacious prediction that India will not succeed to eradicate polio unless his three directives are followed. His first directive to take appropriate remedial measures for the high incidence of vaccine failure is superfluous. His second directive is to introduce IPV on a selective basis and I have already stated its lack of realism at the present time. Eradication of wild- virus polio will be achieved using OPV. His third directive is to develop "some modalities or methodology" for correct case classification. The present methodology is adequate enough and Dr. Paul has no specific suggestion anyway.
T. Jacob John,