Scientists trying to prevent bird flu from killing millions of people have suspended their work because of fears they might accidentally cause the epidemic they hope to stop, according to a letter published on Friday in scientific journals.
Researchers from around the world signed a letter in the Nature and Science journals in which they announced a 60-day suspension to allow a public debate about the security of their work.
The letter comes after developments in the study of bird flu in which scientists have created a similar virus that can be passed between mammals.
Bird flu can only be caught by humans from birds such as chickens but it is usually lethal. Scientists fear that bird flu could mutate into a form that humans could catch from other humans. After the first world war, an influenza mutation (known as Spanish influenza) killed an estimated 40 million people.
Last year, the United States government asked scientific journals to restrict their coverage of the new developments in the study of bird flu out of fear that the information could be used by terrorists to create biological weapons.
Wendy Barclay, professor of influenza virology at Imperial College, London, one of the signatories of the letter, said the influenza research community was fully aware of the risks and benefits of their work.
"The idea of the 60-day pause is to allow time for everyone concerned, media, ethicists and scientists alike, to be involved in the debate," she said. "It is imperative that we do not react on impulse but weigh up the benefits this type of research can bring and review again the appropriate ways to control dangerous pathogens that we work with in the closed laboratory."
Bird flu is believed to have killed about 340 people since it was discovered in 2003. Scientists have worked to create mutations to help the invention of drugs and vaccines to prevent a repeat of the post-first world war Spanish influenza. Although research is carried out under high security, the possibility of human error, accident or a criminal act leading to an escape of the viruses is a constant concern.
In the latest research, scientists created a virus that could be passed between ferrets which are considered good models for human responses to viruses. Last year, Ron Fouchier of the Erasmus Medical College in the Netherlands, who led the team that created the virus, described it as "probably one of the most dangerous viruses you can make".
Scientists are not expected to extend their experiments to test if the new virus can be transmitted between humans because they say it would be unethical.
There have been reports this week of new outbreaks of bird flu in Indonesia and Vietnam. Health authorities reported the second bird flu death this year in Indonesia and the first for two years in Vietnam. The Indonesian ministry of health said there had been a total of 184 cases of bird flu in Indonesia, 152 of which were fatal.
