H5N1 bird flu has caused serious disease and deaths in humans. More than half of the almost 600 patients have died. The virus has not, however, sparked off an influenza pandemic as it cannot spread efficiently from human to human. But research supervised by Ron Fouchier, a fellow virologist in the laboratory that I head at Erasmus Medical Centre in Rotterdam, has shown that only a handful of mutations would allow the virus to spread efficiently among mammals. Similar experiments carried out by a US-Japanese group have yielded largely the same data.

These experiments seem to have rekindled the debate that has smoldered since the last bio-terrorist attacks took place in the US more than a decade ago. The US National Science Advisory Board for Biosecurity has asked the authors of the two scientific papers describing the mutations, as well as editors of Nature and Science – journals where the work should be published – to delete crucial details about the research "that could enable replication of the experiments by those who would seek to do harm"..

To me, the debate about the H5N1 mutations has become a debate about the role of science in society. Two questions should be addressed here: should this type of research be conducted at all; and if so, should all data generated by this research be published?

The answer to the first question is undoubtedly "yes". First of all, recommendations about the scientific research agenda by several international organisations like WHO, EU directorates and NIH (US) have repeatedly stressed the necessity of this type of research. In fact, they have specifically called for studying the molecular basis of mechanisms underlying the transmissibility of animal influenza viruses. But the major reason is that this type of top-level laboratory study is designed to make the world safer, as it will show what makes these viruses transmissible and how we can prepare the world for them. Eventually we may even develop measures to prevent such viruses from emerging. Globalisation apparently predisposes the world for the ever increasing emergence of new infectious disease threats and disasters like Aids, mad cow disease, Sars and influenza. This renders nature itself the principle pandemic threat of our modern world. However, through state-of-the-art scientific research, we have been able to develop effective ways to combat them. Major public health threats have been contained or even eradicated in the past decades: smallpox and rinderpest have been removed from the globe, diseases like polio and measles will be next, and both Sars and mad cow disease were nipped in the bud before reaching pandemic proportions. All direct successes of state-of-the-art research.

This is the principle reason why it would be dangerous not to carry out or continue research on the mechanisms underlying the transmissibility of H5N1 bird flu viruses: the benefits of these studies will largely outweigh the possible risks. Recent research on the reconstructed 1918 Spanish Flu virus may serve as a striking example here. It was conducted in the US under the same containment level as the current studies on H5N1 viruses and has provided an enormous amount of information on how influenza viruses may cause severe disease and how intervention strategies may be developed. Had this pandemic H1N1 virus not been reconstructed, we would still be in the dark about its tricks and traits that will undoubtedly also be used by future pandemic influenza viruses. This has allowed us to reveal their achilles heels. Should this research not have been conducted?

Our current research has also shown that the mutations that are needed to improve H5N1 transmissibility, already exist in the viruses circulating among poultry in Asia today. This has given us a serious wake-up call, warning us that these viruses could spark a pandemic any time now. By sharing our information with our peers and policy makers in the affected areas, we hope to demonstrate that surveillance activities among animals and humans could and should be cranked up for early warning and increased preparedness.

Obviously, the research on the transmissibility of H5N1 bird flu viruses should be, and has been, carried out by responsible scientists under adequately controlled bio-safety and bio-security conditions and safeguards with the appropriate administrative oversight. So, should all research data be published?

Again, in my opinion, the answer is "yes". In science, experiments and their results are shared so others can directly use them and advance the field. Therefore our experiments are part of an integrated and complex process that continuously leads towards a plethora of new knowledge. Follow-up studies will be needed to further enhance our knowledge of pandemic viruses.

After the 1918 virus research team published their full paper in 2005, other researchers poured into the field, leading to hundreds of papers about the virus. Halting or censoring research is hence putting a brake on the scientific process and its public health benefit for society. Slowing down the scientific process does not protect the public, instead it makes us more vulnerable. In fact, it would be a lost opportunity and even irresponsible not to study the mechanisms underlying the transmissibility of avian influenza viruses in mammals.

The proposed "alternative" – disclosing the information to a committee of 20-30 approved experts – is unprecedented and conflicts with established and accepted scientific practice. It also raises more questions than it solves. How to establish a system that is completely safe? How to make sure the wrong people don't get the information and the right people do? Who should decide on which scientists to share the information with? This proposal is neither practical nor sufficient.

Instead, the international community must urgently discuss how to guarantee the best conditions for scientific discovery, while also minimising risk, keeping in mind that the principal bio-terrorist is nature. True science is based on two things: verifiable facts and the desire to apply knowledge for the benefit of humankind. Science must never be impeded by fiction or fear.