Friday, December 28, 2012

OPV an exercise in futility?

Polio eradication was an ideological project

Full article at:

In the 1980s, why was polio, with its rather small mortality rate, chosen for a worldwide “eradication” campaign, when other infectious diseases such as measles, pneumonia, and diarrhoea causing infections each killed millions of children a year? It had little to do with the priorities of most developing countries where polio was endemic. It was more to do with the ideology of a small number of powerful and well placed players in global public health who were dedicated to the concept of so called eradication as perhaps the major tool for international public health.1

Many of these people had been involved in the successful campaign to eradicate smallpox. However, after that great achievement near consensus had formed in public health circles that primary healthcare (including routine immunisation) rather than vertical eradication campaigns should be the focus of global and national efforts. It looked as though smallpox would be the first and last human disease to be eradicated.

Those who I would call “eradicationists” had to find a disease that could be quickly and inexpensively disposed of to keep the concept of eradication alive in the face of popular indifference and active hostility from the World Health Organization.

"Unfortunately, it was not that difficult to get the members of the World Health Assembly to support a major global policy without fully understanding the implications for their own home countries. One of the costs was that national health priorities formulated by developing nations themselves (such as building routine immunisation systems, neonatal health, maternal mortality, controlling diarrhoeal diseases) may have been pushed aside in favour of an agenda that these countries didn’t even know existed. They would not only have had to subordinate their own public health goals to engage in a fight against a relatively minor disease, but they were doing it not merely for the stated goal of vanquishing polio, but to prove the point that disease eradication can be maintained as a major tool of public health. For eradicationists today it is polio, but tomorrow it may be measles, mumps, and rubella. And woe betide any country that should want to put its own health goals above these global aims."

 Vaccine-Derived Polio Virus: Status and Challenges
The "endgame strategy" for polio eradication has taken the scientific community by storm. Almost everything from the choice of vaccine, tactical strategies to the achievability of the eradication target, are being questioned [6] on account of the problem of vaccine-derived polio virus (VDPV). VDPV causes vaccine-associated paralytic polio (VAPP) in a miniscule of OPV receivers. Though high rates of OPV coverage will prevent all poliovirus spread, including spread of VDPVs, it will not prevent establishment of prolonged VDPV infections in certain persons with B-cell immune-deficiencies. [6] Moreover inevitable gaps in vaccination coverage will give rise to VDPVs as long as OPV use continues. Thus even when wild polio transmission is stopped OPV will continue to generate VDPV which in effect means that the risk of polio although very small will remain. 

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