To prepare for future epidemics, the health authority has prioritized viruses and bacteria at risk that require increased surveillance.
- According to the WHO, the number of pathogens likely to trigger the next pandemic has increased to more than 30 by 2024.
- The updated list now includes influenza A virus, monkeypox virus, strains responsible for cholera, plague, dysentery, diarrhea and pneumonia.
- “Some pathogens on the list may never cause an outbreak, and one we haven’t thought of may be important in the future,” says British virologist Naomi Forrester-Soto.
To strengthen the ability to respond effectively to unexpected variants, emerging pathogens, zoonotic transmissions and unknown threats, such as Pathogen X, the World Health Organization (WHO) compared the results of previous lists of viruses and bacteria that were prioritized for research and development for outbreaks in 2017 and 2018 with this year’s results. “It is important to note that the 2024 results incorporate for the first time the concept of the family approach and the addition of the prototype pathogen,” can we read in a report published on July 30.
For the purposes of the work, 200 scientists from more than 50 countries evaluated data on 28 families of viruses and bacteria, or 1,652 pathogens. In order to determine whether each pathogen should be included in the updated list, the experts selected viruses and bacteria from databases, of which there were “substantial evidence of their high transmissibility and virulence“, but also for whom access to vaccines and treatments was limited.
Influenza A, monkeypox: viruses likely to trigger the next pandemic
According to the new list drawn up by the WHO, more than 30 pathogens are likely to trigger the next pandemic. Among them, we now find, in addition to the group of coronaviruses known as “Sarbecovirus” and the “Merbecovirus” responsible for the Middle East respiratory syndrome (MERS), the monkeypox virus. As a reminder, the latter caused a global smallpox epidemic in 2022 and continues to spread in certain areas of Central Africa. It “could potentially be used by terrorists as a biological weapon,” said Neelika Malavige, immunologist at the University of Sri Jayewardenepura in Colombo, Sri Lanka, who participated in the study.
Another virus selected by the experts is influenza A, particularly the H5 subtype, which has triggered an epidemic in cattle in the United States. Among the five bacteria, all newly added, are strains that cause cholera, plague, dysentery, diarrhea and pneumonia. Two rodent viruses have also been added because they have been transmitted to humans, “with sporadic human-to-human transmission”. This is the case with the bat-borne Nipah virus, which is on the list because it is deadly and highly transmissible among animals. In addition, there is currently no treatment to protect against it.
Pandemic: “An agent we haven’t thought of could be important in the future”
According to the researchers, this list of “priority pathogens” will help organizations decide where to focus their efforts in developing treatments, vaccines and diagnostics. However, “Some pathogens on the list may never cause an outbreak, and an agent we haven’t thought of may be important in the future. (…) We almost never predict the next pathogen,” concluded Naomi Forrester-Soto, a virologist at the Pirbright Institute near Woking, UK, who also contributed to the report.