UK Releases New Watchlist of High-Threat Pathogens

The UK Health Security Agency (UKHSA) has identified 24 pathogen families that could pose the greatest risk to public health. The list aims to guide preparedness efforts in diagnostics, therapeutics, and vaccines (DTVs).

The Priority pathogen families research and development (R&D) tool is part of the UK government’s Biological Security Strategy. It highlights pathogens requiring urgent research and development to bolster biosecurity.

A Focus on UK-Specific Threats

This is the first list of pathogen families that considers both global public health threats and those most relevant to the UK population. However, the agency pointed out that the list is neitherexhaustive nor ranked and that health threats could arise from other pathogen families. Moreover, the tool represented a snapshot at one point in time and was intended to be updated annually and used alongside other data.

Mark Woolhouse, professor of infectious disease epidemiology at the University of Edinburgh, welcomed the initiative. However, he noted that the UK’s pandemic preparedness before 2020 was overly focused on influenza. “When COVID arrived, it took too long to adjust our response to a different threat, which was part of the reason we ended up in lockdown,” he told the Science Media Centre.

Need for More Investment in Vaccines and Diagnostics

The UKHSA highlighted recent experiences with COVID-19 and mpox as evidence of the need for stronger DTV pipelines. 

Each family of pathogens included in the reference tool has been given a high, moderate, or low rating for pandemic and epidemic potential. These ratings do not predict the next pandemic but highlight areas needing increased scientific investment and research. These include pathogens for which improved vaccine or diagnostic development is needed, or those that may be exacerbated by climate change or antimicrobial resistance. 

Priority viral families include the Picornaviridae, which encompasses enteroviruses D68 and A71, associated with acute flaccid myelitis. It also features Flaviviridae, which includes dengue and Zika viruses. Among bacterial threats listed are Bacillaceae, which includes Bacillus anthracis (anthrax), and Coxiellaceae, which includes Coxiella burnetii (Q fever).

Measles a Continuing Concern

The UKHSA called for greater research efforts into Coronaviridae, which includes COVID-19, and Paramyxoviridae, which includes measles and Nipah virus. Also, the Orthomyxoviridae family, which includes avian influenza.

“Of the highest priority pathogens identified by the UKHSA, no one could argue with the inclusion of coronaviruses and influenza viruses,” Woolhouse stressed. He added that measles remains a “continuing cause for concern”, with large outbreaks regularly reported from around the world.

“A novel measles-like virus would pose a threat far worse than COVID, and would also be considerably more deadly,” Woolhouse warned.

Scalable, Adaptable, and Responsive

The priority pathogens reference tool contributes to the UK’s contribution to the global 100 Days Mission. Launched during the UK’s G7 presidency in 2021, the mission aims to deploy an effective vaccine within 100 days of identifying a new pandemic threat.

Other similar lists have been compiled by the World Health Organization and the Coalition for Epidemic Preparedness Innovations. However, this is the first to reflect UK-specific public health needs.

In a statement, Dr Isabel Oliver, the UKHSA’s chief scientific officer, said the tool would help focus scientific investment where it can have the greatest impact. “We hope this will help to speed up vaccine and diagnostics development where it is most needed, to ensure we are fully prepared in our fight against potentially deadly pathogens.”

Woolhouse emphasised the need for flexibility in pandemic response. 

“We should not put all our eggs in one basket,” he said. “The possibility of different kinds of threat – different transmission routes, different types of disease, different populations at risk – means that our response needs to be scalable, adaptable, and quick.” 

Dr Rob Hicks is a retired NHS doctor. A well-known TV and radio broadcaster, he has written three books and has regularly contributed to national newspapers, magazines, and online. He is based in the UK.