India could be winning the battle, after all. With no cases of the most dangerous strain of polio virus being reported in erstwhile-afflicted Uttar Pradesh, celebrations may be right around the corner.
Almost all (96 percent) of India's cases in 2006 were of the virulent type-1 strain. This paralyses around 1 out of every 200 children infected and can traverse great distances.
The majority of cases were reported in western Uttar Pradesh, which is India's most populated state, with 170 million people, and also one of its poorest. The state as well as neighbor Bihar is considered fertile grounds for the polio virus to flourish, owing to the tropical climate, crowded towns, poor sanitary conditions, high birth rates and widespread diarrhea among children.
India’s Union Health Minister, Dr Anbumani Ramadoss, has affirmed that with constant efforts there have been no cases of type-1 polio in western Uttar Pradesh in the last six months. India, which aims to eradicate polio by the end of 2008, has seen 103 cases of polio this year against 150 till the end of June last year, but, more importantly, type -1 cases in the first six months have fallen to 39 against 145 year-on-year. Most significantly, no child has been affected by the type-1 strain in the seven worst affected districts of Uttar Pradesh this year.
A member from the WHO's National Polio Surveillance Project(NPSP) in India has given that a transition point has been reached in the fight against the type-1 virus, and once this is taken care of, the next step would be to eradicate the type-3 virus. As a result of the greater focus on immunizing children against type 1 there has been a rise in the cases of less virulent type-3 polio, which need not alarm, as the first step is to get rid of type 1.
In the past, a trivalent vaccine that protects against all three types of polio was used in India, but it was not effective enough against the virulent type-1 strain. As a result, a monovalent vaccine (MOPVI), specifically aimed at the type-1 strain has been put to use in many areas. The type-3 strain paralyses 1 in around 1,000 children infected, and does not travel as far as its counterpart. Other than from India, polio is still present in Pakistan, Afghanistan and Nigeria.
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Yet, Saniya’s is not the only case. There are 15 cases of Type I polio spread across Uttar Pradesh (There are also 41 cases of Type II polio which takes the total count to 56). While there has been no reported Type I case in the endemic Moradabad, the new cases have been reported from eastern and central Uttar Pradesh; so instead of just a region, cases of wild polio are being reported from all over Uttar Pradesh now.
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“She is having polio drops ever since she was four days old. She has had over a dozen doses of the polio drops. We came to know about her polio when she got a high fever. She could barely manage to stand, could not walk at all, after the fever. We took her to the local hospital where they did a stool test. We were later told that she has polio,” Noorjahen recalls. “There must be some thing wrong with the polio drops if even after so many doses my child has contracted polio. The government should test medicines before they are used”, she adds.
Mistrust has also gripped the doctors and field operatives overseeing the vaccination project. Add to this the latest controversy about the MOPVI vaccine, introduced in India by the WHO and the organization’s National Polio Surveillance Project , and the situation cannot look grimmer.
When the MOPVI was launched in India in mid-2005, there was no mention that it was a new vaccine, and therefore no need was felt to examine whether it had been tested. The impression created at the time was that this vaccine had earlier been used in the 60s and 70s in some other countries.
In contrast to this position, the April 21, 2007, issue of the renowned medical journal, Lancet, carried a study titled “Protective efficacy of a monovalent oral Type 1 poliovirus vaccine: a case-control study by Grassly NC, Wenger J, Durrani S, Bahl S, Deshpande JM, Sutter RW, Heymann DL and Aylward RB”. On pages 1356-1362 it says: “A high-potency monovalent oral type 1 poliovirus vaccine (mopv-i) was developed in 2005 to tackle persistent poliovirus transmission in the last remaining infected countries. Our aim was to assess the efficacy of this vaccine in India.”
This without doubt means that the MOPVI is a new, untested vaccine and its use was part of an experiment. This news has outraged the Indian medical community. If this vaccine was new, did the WHO and NPSP test its safety? Head of the pediatrics department of Delhi-based St Stephen’s Hospital, Jacob Puliyel, took up the matter with Lancet. In his strong-worded letter to Lancet’s editor, he wrote: “We are shocked and dismayed that Lancet should have published the paper on the protective efficacy of monovalent oral Type I poliovirus...having overlooked the serious ethical issues involved.” He went on to write, “What was introduced, according to this article, was a new vaccine that was five times more potent than previous vaccines, presumably also with the increased likelihood of adverse effects. No informed consent was taken, nor was the public told that the vaccine was experimental. Efforts were made to give the impression that the monovalent vaccine was not new.”
Lancet asked the authors of the article to respond to the questions raised by Puliyel. In their reply, the authors bypassed the question whether the vaccine was new or not, and put the onus of use of this vaccine squarely on the government of India. “The vaccines assessed were licensed for administration in India by the national regulatory authority, the Drugs Controller General of India. The MOPVI formulation assessed in our study has been used since mid-2005 by the Government of India, and now in over 20 countries around the world.”
Puliyel had another serious objection. He said administering MOPVI without examining its potential harmful effects amounts to experimentation on human subjects. The question that NPSD and WHO have to answer is why polio drops that are five times more potent, which means they carry five times more of the live poliovirus, was indiscriminately administered. Would this not result in overexposure to the live poliovirus and possibly result in vaccine-induced polio? “The oversight body that introduced this experimental vaccine should also have monitored adverse effects,” wrote Puliyel to Lancet. Further, he mentioned: “In the absence of proper post-vaccination surveillance of adverse effects, we have to rely on indirect evidence of possible adverse effects available from the NPSP. Data from Uttar Pradesh (where Grassly and colleagues show improved vaccine efficacy) show an increase in the incidence of non-polio Acute Flaccid Paralysis (AFP, or the weakness of limbs) since the introduction of the monovalent vaccine.”
Doctors in UP are worried about this development. “We want the nature of AFP in these cases to be investigated. It could be due to over exposure to the polio vaccine,” says a senior doctor in Lucknow who has overseen the polio immunization program in UP for years.
So, is India winning the battle? Ask little Saniya's mother.
Source-Medindia
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