Bird Flu, an Emerging Threat?
By Dr Syed Amir
Bethesda, MD

 

The spectacular success of modern medicine is attributed at least in part to the open communication and free flow of ideas, a tradition considered sacrosanct. Scientists meticulously document and publish their findings, failures as well as successes, in medical literature and liberally disseminate them at open scientific forums. Any interference in the process or hint of censorship would cause a major uproar.

In December 2011, the scientific community was stunned when the US National Science Advisory Board for Biosecurity in an unprecedented move requested the world’s two most prestigious journals, Science and Nature, to withhold publication of results of research conducted at two laboratories at Rotterdam in the Netherlands and the University of Wisconsin in the USA. The manuscript described the successful creation of a new strain of the bird influenza virus, H5N1, capable of easy transmission between humans. The engineered virus is so virulent that more than half the people who catch it are likely to die. The studies were performed in ferrets, domesticated mammals, which provided an animal model closest to humans and most suited to test flu viruses.

The Advisory Board, established in 2004, comprises 23 members mostly University-based scientists. It is only a consultative body, without any enforcing authority. The Board members were worried that if terrorists ever got hold of the experimental details contained in the research paper, they might be able to replicate the results and succeed in engineering the highly pathogenic virus, with the potential to unleash a worldwide pandemic. The Journal editors after some deliberations acceded to the request, in view of the potential for great devastation.

The naturally circulating bird flu virus has killed tens of millions of birds since it was first recognized in Hong Kong in 1997. Fortuitously, unlike the common flu virus which is highly contagious in humans and spreads through sneezing and coughing, the bird flu virus is not easily transmitted to humans. It is known to have infected only those few individuals who live in close proximity to domestic birds. Yet, as in birds, it is lethal in humans and can kill 60 to 80 percent of its victims. In comparison, seasonal flu kills less than one percent of those it infects.

A well-known characteristic of all viruses is their remarkable ability to change or mutate spontaneously. It is not known how or why they do so, or how they acquire the ability to spread in humans. In the past, some viral mutations have proven particularly deadly. In 1918-19, a devastating Influenza pandemic, known as the Spanish Flu, swept across the globe and took an estimated 100-million lives. Almost 17 millions died in India alone. In some American cities, the mortality rate was so high that mass graves had to be dug to bury the dead. Unlike the common flu, which mostly kills the old and infirm, the Spanish flu was especially fatal in young people, as it viciously destroyed their lungs, turning the skin to reddish brown. More recently, in 2009, a new and virulent influenza virus evolved drawn from some animal reservoir that swiftly spread in humans threatening a major epidemic; fortunately it had a short life span. Nevertheless, the pharmaceutical companies found it difficult to manufacture adequate amounts of the vaccine to prevent its global spread.

Since the advent of Spanish flu a century ago, scientists have been haunted with the specter of another viciously pathogenic flu strain emerging, leading to a biological calamity. Concern has grown now, since it took just a few mutations in two genes to transform the bird flu virus, relatively non-threatening to humans, into an airborne pathogen capable of infecting millions, much like common flu. It is plausible that such transformation would occur spontaneously in nature sometime in future.

The engineered bird flu virus, nonexistent in nature at this time, has fueled a lively debate among scientists whether research with so much sinister implications should have been undertaken in the first place. Others dismiss such reservations, and believe that the overall benefits of research far outweigh any potential risks. The National Institute of Health (NIH), the premier research funding agency in this country, which supported the virus research, also strongly justifies the study. In an article in Washington Post, the NIH director and colleagues contended that the studies were timely and highly appropriate. They were designed to illuminate the mutation pathways of the bird flu virus, and delineate early structural features indicating that it was about to acquire wide transmission ability.

Such knowledge would be invaluable to investigators in designing an effective vaccine and life-saving antiviral drugs before the virus had a chance to get established. The NIH officials conceded, however, that they cannot be certain if the strain generated in the laboratory would follow the same transmission route in humans as it did in the animal model in which the studies were conducted. The scientists are now faced with the challenge of how to make the new scientific knowledge available to genuine investigators, while taking scrupulous steps to prevent it from reaching those who would put it to ill use.

 

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