Experts are concerned about the virus due to its apparently high fatality rate and worry that the virus could pass from human-to-human. This could spark an epidemic like the one caused by the H5N1 bird flu virus which killed 371 people in 2003.
However, Chinese officials say there are currently no cases of the disease spreading from one human to another, even though health authorities have traced hundreds of people who had contact with the 24 known cases.
The virus was previously only seen in wild birds but was found in domesticated birds last week (4 April 2013) and subsequently discovered in pigeons at a Shanghai live bird market. In contrast to H5N1 bird flu, birds carrying H7N9 do not come down with any symptoms making it difficult to trace infected animals. Chinese authorities immediately began culling every bird at the market as part of a multi-agency response to the crisis.
US health authorities say their scientists are working on a seed vaccine which if needed could then be grown and produced in larger quantities by manufacturers – a process that starting from the seed vaccine is known to still take several months before a first dose of vaccine would become available for use.
The move was described by the Centers for Disease Control (CDC) as “a precaution”, but experts acknowledged that the vaccine development process had been initiated as reports of new cases continue to come in.
It will be at least a month before the seed vaccine is ready but that work was facilitated by China’s decision to post details of the genetic sequences of the virus on public databanks. This has enabled US scientists to ‘build’ their own version of the virus in a lab rather than waiting for samples to be posted from Shanghai.
The WHO has produced a fact sheet addressing some of the questions raised by the outbreak, saying that there are currently no concerns about visiting China or consuming Chinese products.
However, several countries, including Vietnam, have already banned imports of Chinese poultry, while Japan is posting notices in airports urging people to report flu symptoms to officials. Hong Kong has halted imports of live birds from mainland China.
The European Centre for Disease Prevention and Control (ECDC) says the risk of the disease spreading to Europe is currently low but the situation is being monitored closely.