The Global Preparedness Monitoring Board (GPMB), co-convened by the World Bank and the World Health Organization (WHO), warned that epidemic-prone viral diseases like Ebola, flu and SARS are increasingly tough to manage in a world dominated by lengthy conflicts, fragile states and forced migration.

“The threat of a pandemic spreading around the globe is a real one,” the group said in a report released on Wednesday. “A quick-moving pathogen has the potential to kill tens of millions of people, disrupt economies and destabilize national security.”

While some governments and international agencies have made efforts to be vigilant and prepare for major disease outbreaks since the devastating 2014-2016 Ebola outbreak in West Africa, those efforts are “grossly insufficient”, the report said.

Gro Harlem Brundtland, a former WHO head who co-chaired the board, added that current approaches to disease and health emergencies are “characterized by a cycle of panic and neglect.”

The report cited the 1918 “Spanish flu” pandemic, which killed an estimated 50 million people. With vast numbers of people crossing the world on planes every day, an equivalent air-borne outbreak now could spread globally in less than 36 hours and kill an estimated 50 million to 80 million people, wiping out nearly 5% of the global economy, it said.

Reuters reports that in the case of a pandemic, many national health systems – particularly in poor countries – would collapse.

“Poverty and fragility exacerbate outbreaks of infectious disease and help create the conditions for pandemics to take hold,” said Axel van Trotsenburg, acting chief executive of the World Bank and a member of the panel.

Calling on governments to “heed the lessons these outbreaks are teaching us” and to “fix the roof before the rain comes”, Tedros Adhanom Ghebreyesus, director-general of the WHO, said they should invest in strengthening health systems, boost funds for research into new technologies, improve coordination and rapid communication systems, and monitor progress continually.

The WHO also warned earlier this year that another pandemic of flu – which is caused by airborne viruses – is inevitable, and said the world should prepare for it.