United Kingdom health officials have identified the 24 deadly pathogens that pose the greatest future threat to public health in a groundbreaking new assessment tool that aims to assist global research.

The UK Health Security Agency, or UKHSA, on Tuesday shared its new list of viruses and bacteria that pose biosecurity concerns due to limited testing capabilities, lack of vaccines, and growing risks from climate change and drug resistance.

Five years after the first COVID-19 lockdown in the UK, experts are urging more research is carried out into deadly pathogens like bird flu, plague, and Ebola, citing their potential for worldwide spread amid changing climate patterns.

"A large outbreak overseas could have major impacts globally, including socioeconomic impacts," warned Isabel Oliver, the UKHSA's chief scientific officer, as health authorities aim to better prepare for future threats.

The list also includes other dangerous viruses such as Marburg, dengue, and Zika, along with bacteria causing anthrax.

Health officials will review the list annually, learning from the COVID-19 experience when preparations had focused solely on influenza threats, the UKHSA said.

Oliver explained that scientists had assessed "not just the fact that some of these families have got high potential to cause pandemics or epidemics, but also where there are currently gaps in the availability of either diagnostics, vaccines and therapeutics, or where there are evolving and growing changes around antimicrobial resistance, or where there is a significant sensitivity to climate change, that might mean that this threat evolves or changes more rapidly".

A key concern highlighted in the assessment tool was "the change in the distribution of mosquitoes and ticks that can carry viruses that cause adverse health effects to humans" due to environmental and climate shifts.

Future updates will involve collaboration with animal health experts, Oliver added, given that many emerging diseases originate in animals before infecting humans.

The assessment also identifies antibiotic-resistant bacteria as a growing threat, including pathogens like gonorrhea where current treatments are becoming less effective.

The list includes measles and related viruses, which are particularly concerning to experts.

Supporting the UKHSA's findings, infectious disease expert Mark Woolhouse, from the University of Edinburgh, said: "A novel measles-like virus would pose a threat far worse than COVID. Such a virus would have a much higher R number (indicating how contagious an infectious disease is) than the original variants of COVID, making it impossible to control by even the strictest lockdown. It would also be considerably more deadly, and (unlike COVID) it would be a threat to children. This is the kind of pandemic that public health agencies around the world are most concerned about."

"That said, there are many potential kinds of novel pandemic threats — so-called Disease X — and the UKHSA report is a timely reminder that we should not put all our eggs in one basket," Woolhouse said.