AS BIRD FLU continues to rampage across south-east Asia, the question is whether this will be The Big One 鈥� the virus that mutates to rival the 1918 flu strain, which killed tens of millions of people. And the truth is, we have no idea. The existing H5 bird flu can infect and kill people, but not easily, and it cannot yet spread between people. It is possible that it will evolve into a human plague on its own, or hybridise with a human flu virus and become contagious that way. Or maybe H5 cannot do this. We just don鈥檛 know.
If one way or the other it does turn into a human plague, we will be in big trouble. Any hybrid bird-human virus is bad enough: the last one, in 1968, killed thousands of people. But this time it could be worse. More than two-thirds of those unlucky enough to have contracted the H5 virus have died. If it becomes contagious, we could see a repeat of 1918, or worse. Even modern drugs and vaccines are not guaranteed to save us because we would struggle to produce enough to stave off a fast-moving virus (see 鈥淒own with the flu?鈥�). We would certainly need the earliest possible warning.
In the light of these facts, some researchers want to find out what will happen if bird flu acquires a few different genes. Some of this work is already under way at the Centers for Disease Control (CDC) in Atlanta, Georgia. The general idea is to mix H5 a human flu strain and see what happens, or tinker with H5鈥檚 genes to discover which mutations confer that dreaded ability to spread between people. If creating a lethal, pandemic strain of flu sounds risky, that鈥檚 because it is. Not surprisingly, the plans have divided biological researchers (see 鈥淪uperflu is being brewed in the lab鈥�).
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Supporters argue that finding out today which genes enable flu viruses to infect humans, kill them, and pass between them would allow action to be taken from the very day a new strain is identified. Critics say this is an unrealistic goal. How do you test a virus鈥檚 ability to spread and kill when giving it to people is out of the question? And mutations created in the lab are not always the same as those that happen in the real world. We could end up with lethal super flu that would never have emerged in the wild.
Perhaps if we could be sure that any super virus would never escape from a lab, critics might be less alarmed. But containment is not always as tight as it could be. Strangely, the work at the CDC is not being done in a lab with the highest safety precautions 鈥� on the grounds that it is an avian virus. The same is true of experiments at the US Department of Agriculture鈥檚 Southeast Poultry Research Laboratory in Athens, Georgia, where researchers created viruses containing five of the eight genes from the 1918 strain. They reasoned that five genes would not be enough to recreate the lethal qualities of the original virus. Worryingly, these decisions seem to err on the optimistic side, without considering the final, potentially nasty form their engineered viruses might take.
Terrorism is another issue. A virulent strain would have to be guarded, and that means being confident about everything from the physical security around the lab to who works inside. And what happens when the experiments are over? Should the viruses be stored or destroyed, and how much experimental detail should be published?
A release could have global consequences, and decisions on these issues should not be left to local biosafety committees. The US National Academy of Sciences (NAS) has rightly recommended a new tier of national approval for experiments such as these and called for other countries to set up similar systems (Biotechnology Research in an Age of Terrorism, National Academies Press, ). There is a case for tougher measures still. Researchers should have to justify every aspect of their work so that the risks and benefits of every experiment can be carefully weighed. Only those likely to yield practical, meaningful results should be allowed.
But, by helping to prevent an influenza pandemic, the research now being proposed 鈥� risky as it is 鈥� could save millions of lives. The threat of pandemic disease is undeniable. If today鈥檚 flu doesn鈥檛 get us, history tells us that another one will. And the only tool we have to defeat such threats is science.