It could take just 36 hours for an airborne illness to travel around the world and kill 80,000,000 people, experts have warned.
Current efforts to prepare for a deadly outbreak are grossly insufficient, a new report by the Global Preparedness Monitoring Board (GPMB) has revealed.
Instead, a future pandemic similar to the Spanish flu could spread faster than ever before due to modern advances in international travel, the document said.
Entitled A World At Risk, the report states: The threat of a pandemic spreading around the globe is a real one.
A quick-moving pathogen has the potential to kill tens of millions of people, disrupt economies and destabilise national security.
The report said some governments and agencies had made efforts to prepare for deadly diseases after the devastating Ebola outbreak left over 10,000 people dead between 2014 and 2016.
However, it said those efforts were grossly insufficient, adding that world leaders had ignored many of the recommendations made in an earlier report.
It said: Many of the recommendations reviewed were poorly implemented, or not implemented at all, and serious gaps persist.
For too long, we have allowed a cycle of panic and neglect when it comes to pandemics: we ramp up efforts when there is a serious threat, then quickly forget about them when the threat subsides. It is well past time to act.
The report added that the threat of a rapidly moving, highly lethal pandemic of a respiratory pathogen is very real.
This could kill between 50,000,000 to 80,000,000 people and wipe out nearly five per cent of the worlds economy, it said.
It continued: A global pandemic on that scale would be catastrophic, creating widespread havoc, instability and insecurity. The world is not prepared.
Many national health systems, particularly in poorer countries, would collapse as a a result, the research said.
A global map showing a list of possible illnesses that could spark an outbreak included Ebola, Zika and Nipah viruses, which were all described as newly emerging.
It also listed measles, yellow fever, Dengue, the plague and human monkeypox as re-emerging and re-surging diseases.