WHO ranks world’s worst pathogens at risk of sparking pandemics

WHO to convene over 300 scientists to consider evidence of more than 25 virus families and bacteria

The World Health Organization (WHO) said on Monday that it is developing a new priority list of pathogens with the potential to spark global pandemics or outbreaks.

It hopes the new list will accelerate research on the threats posed by these diseases before they emerge as outbreaks in humans and can help shorten the timeline for developing safe, preventive medical countermeasures such as diagnostics, treatments and vaccines.

The global health agency said it is convening more than 300 scientists as part of the effort to consider evidence of over 25 virus families and bacteria.

“To support this effort the R&D Blueprint will convene 20-25 viral family groups of experts to independently review the science and to shortlist viruses of concern,” the WHO said in a statement.

Scientists will attempt to identify representative viruses within a viral family to fill knowledge gaps that may be applicable to other viruses of threat in the same family.

This approach can help understand entire classes of viruses instead of just individual strains and thus improve the capability to respond to unforeseen strains and zoonotic viruses that could jump to humans from animals, the agency explained.

Researchers will also consider the potential threat of Disease X, a designation used to indicate an unknown pathogen that could cause a serious international epidemic.

The list was first published in 2017 and updated in 2018.

It currently includes Covid-19, Middle East respiratory syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), Crimean-Congo haemorrhagic fever, Ebola virus disease and Marburg virus disease, Lassa fever, Nipah and henipaviral diseases, Rift Valley fever, Zika and Disease X.

“Targeting priority pathogens and virus families for research and development of countermeasures is essential for a fast and effective epidemic and pandemic response,” Michael Ryan, Executive Director of WHO’s Health Emergencies Programme, said in a statement.

“Without significant R&D investments prior to the Covid pandemic, it would not have been possible to have safe and effective vaccines developed in record time,” Dr Ryan said.

The list will help scientists lay out knowledge gaps and research priorities for these diseases.

“This list of priority pathogens has become a reference point for the research community on where to focus energies to manage the next threat,” WHO’s Chief Scientist Soumya Swaminathan said.

“It is developed together with experts in the field, and is the agreed direction for where we – as a global research community – need to invest energy and funds to develop tests, treatments and vaccines. We thank our donors like the US government, our partners, and the scientists who work with WHO to make this possible,” Dr Swaminathan added.

The revised list is expected to be publicly released in the first half of 2023.

The organisation believes the list can guide targeted efforts to develop roadmaps for each priority pathogen and the development of ideal medical countermeasures to these diseases as well.