Letters to the Editor

Indian Pediatrics 2002; 39:788-790

Reply

There has been much debate, in recent years, about the lAP recommendation for universal infant immunization with hepatitis B vaccine. While the Government of India has accepted the need for this intervention, based on recommendations by lAP and other organizations, and is planning to take preliminary steps towards implementing it, some lAP members remain unconvinced of its need.

The WHO has grouped all countries as having low, intermediate or high prevalence of chronic HBV infection. India has been accepted as an intermediate prevalence country, with the rate falling in the range of 2 to 7 per cent. This is a convenience classification, using a broad brush. Drs Anand and Ashok argue that India should be considered as a low prevalence country as they believe that the true rate is below 2%. They are quite justified in holding such a view, since nobody knows exactly what the true rate is. The reality is that reliable data to arrive at a valid figure are lacking. No amount of statistical refinement can replace good data. There has not been a study aimed at arriving at a national average rate of prevalence. Even for HIV prevalence, a systematic approach to calculate national average was established only a couple of years ago. It is multi- centre involving over 300 study sites. I doubt if such a study for HBV will be undertaken by any agency in India, and let me also state that there is not much need to know exactly what the prevalence rate is. In the absence of such a study or a validated prevalence rate, what experts can do is to take the results of all available studies and come up with an estimated range within which the truth should lie. Whatever the statistical criticism, the fact remains that the "consensus" estimate arrived at by INASL remains 4.7% and we had certainly not misquoted this information. What we had said in our letter commenting on the earlier paper by Lodha, Jain and colleagues was that it was unfair for them not to have confronted the INASL "consensus" figure in their exercise to arrive at their new estimate(1). By attempting to confront the INASL estimate, Drs Anant and Ashok have agreed with us, but they mistook that lAP relied only on that one figure for formulating its recommendation. That was not the case.

Granting that the INASL consensus estimate suffers from flaws, it is for Drs. Anand and Ashok to take this matter up with INASL or debate it through scientific journalism, which I understand they are already doing. lAP does not have to defend it. The estimates of Drs. Anant and Ashok, using selected data from the INASL review, range between 1.42% and 2.41 or 2.64%. Discarding the study by Singh, Prakash and colleagues (2), which showed relatively higher rates, suggests that the authors are perhaps more concerned with finding selective support for their viewpoint rather than using all available evidences to arrive at the range of best estimates. It is because we do not have reliable data and valid result, that a group of INASL investigators got together and arrived at a consensus figure, which is still an estimate only. It is not to be mistaken for a valid rate. The rates of chronic infection vary widely among population subgroups within one place, and also between places. Therefore any estimate, based on local studies at varying times and using different sampling styles and testing procedures would have flaws in the base data and the assumptions used in arriving at an estimate. The "worked out" HBsAg carrier rate of 1.42% also suffers from all the above problems and cannot be accepted as a valid figure as proposed by Drs Anant and Ashok. Their desired revision is to withdraw the recommendation for universal immunization, and to replace it with something else, such as perhaps selective immunization. That will indeed be retrograde. If we had assumed that the carrier rate to be 4.7%, then why would we carefully qualify it as a "consensus estimate"? Thus, the "unscientific assumption of a carrier rate of 4.7%" as the basis of lAP’s recommendation, is itself an unverified assumption. Drs Anant and Ashok erred to presume that the lAP recommendation was merely to echo the WHO guideline for universal immunization to be established by 1997 in countries with intermediate (or high) prevalence. If we were to simply endorse WHO guidelines or to accept the Government policy, then what is the role of lAP Immunization Committee?

The decision to recommend universal immunization was taken in the best interests of the nation and its children and the debate over the statistical methods arriving at a national average has very little to do with it. We were guided by the voluminous data on the frequency of hepatitis B infection (acute and chronic), chronic liver diseases and consequent deaths, than by one estimated national average of chronic virus infection alone. HB vaccine has turned out to be quite popular among many. Many if not most infants born in well-to-do families are getting the benefit of immunization. Are the economically underprivileged children to be denied this benefit? How best can we ensure equity in preventing HB virus infection and its consequences in all individuals? We believe that equity cannot be achieved without a national policy of universal immunization. The choice belongs to each sovereign country; what WHO provides is only guidelines and not international decree.

Many lAP members (not Drs Anand and Ashok) have expressed their concern (in various forums) that pharmaceutical companies reap much profit from HB vaccine. One way to look at a recommendation for universal immunization is to suspect that its motive might be the financial interests of the companies. Many of us in clinical practice also get profit through immunization. We clinicians, the Government and the pharmaceutical companies are truly partners in child health and all three parties must be guided by the principles of science, quality and equity. What is best for the future of India’s children is that every one is protected from HB virus infection. With a Government policy for universal immunization the price of the vaccine is very likely to fall in the range of some 25 Rupees per dose. In the absence of such a policy, the prices are unlikely to fall from what they are today, since the sale is mostly in the private market and marketing and advertising costs are usually added to the vaccine prices. Before measles vaccine was accepted for universal immunization (in 1984-85), its price was about 40-50 Rupees and with the change in policy the price fell to 5-10 Rupees. I recall that there was much opposition (from lAP members) even for measles immunization in the early 1980’s. In the relentless march of progress, those who stand in its way have a tendency to be left behind, as we have seen on many occasions in recent memory.

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References

1. Lodha R, Jain Y, Kabra SK, Pandav CS. Hepatitis B in India: A review of disease epidemiology. Indian Pediatr 2001; 38: 349-371.

2. Singh J, Bhatia R, Khare S, Patnaik SK, Biswas S, Lal S et al. Community studies on prevalence of HBsAg in two urban populations in southern India. Indian Pediatr 2000; 37: 149-152.