When news surfaced last week of possible human-to-human transmission in a cluster of people infected with bird flu in Thailand, the world reacted with surprising calm. Perhaps there has been one panic too many for the global media to spend too long on this story. One wire service even described the World Health Organisation as playing down the threat. This is something of a surprise to anyone who has read the transcripts from the briefing given in Geneva last Wednesday by Klaus Stohr, the WHO's co-ordinator of the global influenza programme. Dr Stohr is not a panic merchant. But the essence of his message was that if this latest cluster of infections has been caused by an avian flu virus with the capability to pass easily from human to human, then we are in a lot of trouble. How much trouble? We should expect one in six people to become seriously ill, rapidly filling our hospitals and intensive care units, far beyond what we experienced during Sars, according to a projection by the Centres For Disease Control and Prevention (CDC) in Atlanta, Georgia. Worldwide it predicts at least 7.4 million deaths. 'An influenza pandemic has a greater potential to cause rapid increases in death and illness than virtually any other natural health threat,' says the CDC in its influenza pandemic preparedness draft plan, released last August. And it is this 'preparedness' that worries Dr Stohr and his colleagues in Geneva. 'Currently, only 50 countries worldwide have pandemic preparedness plans,' he said. 'Very few countries have thought about how they're going to use the vaccines, if there is something available, or how they're going to use the antivirals.' The good news is that Hong Kong is one of the few countries that have developed such a plan. It was stimulated more by our experience with Sars last year than a fear of bird flu, but the surveillance system - preparing hospitals and the community with colour-coded alerts - has gone some way towards making the health system more responsive. But it is not just being prepared; it is about a commitment to do something. During his briefing, it became clear that Dr Stohr and his colleagues around the world are frustrated with the commercial realities involved in vaccine development. Although the bird flu virus has been fully gene sequenced and made available for vaccine development, only two companies, Chiron and Aventis, both in America, have got as far as producing a clinical batch. The US National Institutes of Health is funding studies to ensure the vaccine is safe and effective, but the test results will not be available before February or March. That is a start. But we could be doing so much more. Nothing is happening in Europe, which has 70 per cent of the world's vaccine-producing capacity. It means we are unlikely to have anything like the level of vaccine needed against this natural disaster. Vaccines do not make money until they are used, and the bird flu vaccine will only be used once the virus spreads. By then, of course, it will be too late for most of us. The WHO recognised this more than four years ago, saying in its influenza preparedness plan that 'without a clearing house to balance demand and supply, cost considerations, rather than public health, may drive vaccine distribution needs'. Dr Stohr put it in simpler terms: 'It will be a very difficult decision to take by governments to decide who is going to receive the vaccine ... or even more importantly, who is not going to receive the vaccine.' So, for instance, if we were to vaccinate health-care workers, should we also vaccinate their children? Margaret Cheng is a Hong Kong-based medical writer