The World Health Organisation (WHO) has released a list of germs that could potentially cause the next pandemic.

The updated list of 30 pathogens is comprehensive, with some classified as “priority” because of their potential to cause a global public-health emergency in people.

More than 200 scientists spent nearly two years evaluating evidence on 1,652 pathogenic species, most of them viruses and some bacteria, to decide which species to include on the list, as noted in the peer-reviewed journal Nature.

“The priority setting process helps identify critical knowledge gaps that need to be addressed urgently, and ensures the efficient use of resources,” said Ana María Henao Restrepo, who led the World Health Organization’s Pandemic Research and Development Blueprint team that prepared the report.

Researchers say the list of ‘priority pathogens’ will help organisations decide where to focus their efforts in developing treatments, vaccines and diagnostics.

More than 200 scientists studied 1,652 pathogen species, most of them viruses and some bacteria, for two years to decide which species to include on the priority list.

The more than 30 priority pathogens include coronaviruses such as sarbecoviruses, which includes SARS-CoV-2 (the virus behind the COVID-19 pandemic), and merbecoviruses, which includes the virus that causes Middle East respiratory syndrome (MERS).

Previous lists contained the names of the specific viruses of SARS and MERS, but now include entire subspecies.

The list also includes the monkeypox virus, which is responsible for a global outbreak in 2022 and is still spreading in central Africa.

The variola virus that causes smallpox is also a priority, even though it was eradicated in 1980. That’s because people no longer routinely get vaccinated against it, making potential outbreaks dangerous.

According to Neelika Malavige, an immunologist at the Sri Jayewardenepura University in Colombo, Sri Lanka, who is involved in this effort, this virus can also be used as a biological weapon.

Several influenza A viruses, including subtype H5 (which has caused outbreaks in US cattle), are now on the list. Newly added bacteria include those that cause cholera, plague, dysentery, diarrhea, and pneumonia.

Two rodent viruses have been added because they can jump to humans and spread between people.

Researchers said that due to climate change and urbanization the risk of these viruses spreading to humans has increased.

The bat-borne Nipah virus remains on the list due to its deadly nature and lack of treatment.

Many of these pathogens are currently restricted to certain regions but could potentially spread throughout the world, according to Naomi Forrester-Soto, a virologist at Britain’s Pirbright Institute who helped conduct the analysis.

She studies the Togaviridae family, which includes the chikungunya virus. “There’s no one place that’s at highest risk,” she said.