The World Health Organisation’s decision that it is too early to declare an international public health emergency over the coronavirus outbreak has been met by mixed reaction.

Some experts agree with announcement, while others are surprised at the stance.

There are even suggestions the WHO is keen to avoid repeating the mistakes of the past, by declaring an emergency without having enough information.

Martin Hibberd, Professor of emerging infectious disease, at London School of Hygiene and Tropical Medicine, said: “This announcement is not surprising as more evidence may be needed to make the case of announcing a PHEIC (Public Health Emergency of International Concern).

“To estimate the true severity of this new disease requires identifying mild or asymptomatic cases, if there are any, while determining the human to human transmission rate might require more evidence.

“WHO were criticised after announcing the pandemic strain of novel H1N1_2009, when the virus was eventually realised to have similar characteristics to seasonal influenza and is perhaps trying to avoid making the same mistake here with this novel coronavirus.

“However, all this new evidence needs to be rapidly obtained over the next few days if the world is to be as prepared as possible, so WHO should issue a different type of alert to mobilise a full investigation.”

While Dr Stephen Griffin, associate professor at the  University of Leeds, said he was surprised at the WHO’s decision given that the new strain appears similar to Sars.

He added: “We have 4th generation spread and the proportion of severe cases appears high.

“However, it is often difficult to understand the precise criteria by which one of these is implemented – it sounds as though the committee had some differences of opinion.

“I suppose there is a track record of relative caution in these decisions- look at the delay for  both of the large Ebola virus outbreaks.

“My hope is that this is not a decision that we might come to regret.”

Peter Piot, professor of global health and director at London School of Hygiene and Tropical Medicine, said the outbreak is in a “critical phase” and regardless of the WHO’s decision intensified international collaboration and more resources will be crucial to stopping it.

He continued: “National authorities and the World Health Organisation will need to continue to monitor developments very closely.”

“There are still many missing pieces in the jigsaw puzzle to fully understanding this new virus which is spreading rapidly across China, and most probably around the world.

“Over the coming days and weeks we will know much more, but there cannot be any complacency as to the need for global action.”

Prof Piot added that it was good news that data suggests the virus may have a lower mortality than Sars, and there is a diagnostic test.