March 25, 2025

expert reaction to UKHSA’s new Priority Pathogens reference tool

Scientists comment on the UK Health Security Agency’s new Priority Pathogens reference tool for R&D funders.

Dr Catrin Moore, Reader in Global Health and Infectious Diseases at St George’s, University of London, and co-Chair of the Microbiology Society’s Impact and Influence Committee, said:

“The tool is useful in bringing a lot of information together in one place.  The work as described fits my understanding of pandemic/epidemic potential, and vaccine availability.  I would however like to understand how they came to these conclusions, what methods they used and which papers they took the information from.  I’m also keen to see the diagnostics to understand which diagnostics the team could find.

“It is difficult to determine the quality of the research presented in the report given there are no references, no information on where the data was derived from and the authors are not listed on the report.

“There will be more susceptible people within the general populations who will be at more risk of disease compared to others which are not described in this work.  Also there are some notable omissions, for example Mycobacterium tuberculosis which was recently added to the World Health Organizations Bacterial Priority Pathogens List, 2024.

“Without understanding the methodology used in this work it is difficult to understand whether there is any overspeculation.  The team have brought together a good list to begin with, however I would like to see more evidence to back up their tool and the methodology behind the results they have published.”

Prof Jose Vazquez-Boland, Chair of Infectious Diseases, University of Edinburgh, said:

“The establishment of these priority lists is a double-edged sword when it comes to research into pathogens and infectious diseases.

“While at first glance it may seem like a logical step and could indeed help streamline and focus research efforts, the intended prioritization comes with a risk.

“In a context where research funding and resources are increasingly scarce, research on pathogens or infections that, while still very important, are not on the priority list could receive insufficient or no funding.

“This would have negative consequences, as only a comprehensive understanding of a diversity of pathogens and the common themes and specificities in their infection biology can facilitate the identification of intervention targets or rational control measures, or more accurate predictions in terms of emergence of new threats in response to ecosystem changes – which may involve “non-priority” pathogens.

“In my opinion, the bacterial pathogens list is rather limited and predictable.  It also omits as a research priority on its own critical cross-cutting issues, such as antimicrobial resistance, which by its very nature can be horizontally transferred between different bacterial pathogen groups/families.”

Prof Emma Thomson, Director of the MRC-University of Glasgow Centre for Virus Research, said:

“The UKHSA’s new Priority Pathogens reference tool is an important and valuable resource that will help to guide national research efforts and improve preparedness for future infectious disease threats in the UK.  By highlighting pathogen families of greatest concern to public health, this tool will enable more strategic investment in diagnostics, vaccines, and therapeutics, focusing attention where it can have the greatest impact.  From a scientific perspective, the list is particularly helpful in identifying gaps in our current understanding of high-risk pathogen families and the areas where new research and countermeasure development are most urgently needed.  Many of the listed families—such as Coronaviridae, Paramyxoviridae, and Orthomyxoviridae—are already recognised as significant threats, but the tool also highlights less well-characterised families where pandemic or epidemic potential remains underexplored.

“It is essential that this list remains dynamic and responsive to emerging threats.  History has shown that pandemic risks can arise from unexpected sources.  For example, coronaviruses and retroviruses were not widely regarded as major threats before SARS-CoV-1 and HIV-1 emerged, respectively.  Flexibility and regular reassessment of the list will be crucial to ensure preparedness keeps pace with the evolving pathogen landscape.  The concept of Disease X also remains critical in this context.  There are an estimated 320,000 undiscovered viruses in wildlife that could have spillover potential.  Enhanced technologies for virus discovery and characterisation—such as unbiased metagenomic sequencing and improved surveillance—will be essential to ensure that novel pathogens are rapidly identified and assessed for pandemic potential.  The UKHSA tool provides a strong and vital framework for guiding preparedness, but it must retain flexibility to account for emerging pathogens that have not yet been recognised, an issue that is recognised by UKHSA via its mSCAPE programme.

“The MRC-University of Glasgow Centre for Virus Research strongly supports UKHSA’s effort to provide a structured framework for research prioritisation.  This tool will not only help scientists focus their efforts but will also strengthen collaborations between academia, industry, and public health agencies.  The integration of this reference tool into the broader UK Biological Security Strategy represents a strategic step forward in building resilience against future infectious disease threats.”

Prof Martin Hibberd, Professor of Emerging Infectious Disease, London School of Hygiene & Tropical Medicine (LSHTM), said:

“I am pleased to see a guidance description for pathogens in a UK context being released, and that it will be up-dated yearly. As mentioned in the report, these lists cannot be comprehensive and different perspectives are likely to lead to different conclusions, but it’s release is likely to lead to more widespread consultations and honing of the findings for next year. While all the pathogen families are important, the three identified as priorities (Covid-19; Nipah virus; and avian influenza) are not surprising and I expect perhaps a more detailed, UK specific, priority list next year.”

Darius Hughes, UK General Manager at Moderna, said:

“This important work directly supports Moderna’s strategic partnership with the UK Government to strengthen national pandemic preparedness. By aligning our scientific innovation with the UKHSA’s priority pathogen list, we can help accelerate the development of vaccines where they are most urgently needed. This ensures our joint efforts are focused, forward-looking, and capable of responding rapidly to emerging biological threats—ultimately supporting the UK’s ambition to lead in global health security and protect public health through sustained innovation and collaboration.”

Prof Miles Carroll, Professor of Emerging Viruses, Pandemic Sciences Institute, University of Oxford, said:

“This new Priority Pathogen Families R&D Tool from UK Health Security Agency is aligned with similar prioritisation from the UK Vaccines Network and the World Health Organization, but with a UK focus for obvious reasons.

“The new R&D Tool is consistent with existing evidence, which is helping guide funders, policymakers and scientists on the most urgent research gaps in epidemic and pandemic pathogen threats.  Tools like this are important if we are to develop effective diagnostics, vaccines and treatments to support the UK Biological Security strategy.”

Prof Robert Read, Professor of Infectious Diseases, University of Southampton, and Editor in Chief, Journal of Infection, said:

“Lists like this have been made for many years, and they represent an effort to prioritise infections for advisory and funding purposes, ostensibly to align research funding as closely as possible to public health need.  Unfortunately, pathogens emerge or change constantly, and it is difficult to predict big infectious disease problems coming down the line.  For this reason, I think this list is at best pointless, and at worst potentially harmful to the public health.

“Pointless because the list of viruses is so long that its tricky to name a significant viral pathogen that has not been included.  Potentially harmful because a prescriptive list like this could misdirect funding towards certain infections, and away from problems that need urgently to be solved.  For example, the list of bacteria of concern includes Yersinia pestis (the cause of plague, a massive problem in 14th-18th Century Europe) for which there is now good available treatment and potential vaccine candidates, but does not include Bordetella pertussis (the cause of Whooping Cough) which caused serious problems for the public during 2024 because vaccines remain sub-optimal and antibiotic treatment only works during the early phase.”

Prof Mark Woolhouse, Professor of Infectious Disease Epidemiology, and Director of the Tackling Infections to Benefit Africa, University of Edinburgh, said:

“A key recommendation of the UK Covid Inquiry’s Interim Report for Module 1 (Preparedness) was that prior to 2020 the UK was overly focussed on the risk of an influenza pandemic.  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.

“Since the pandemic, there have been many initiatives to better understand the diversity of pandemic threats that the UK and the world may face in the coming years.  The UKHSA’s pathogen prioritization exercise is a welcome contribution to this global effort.

“Of the highest priority pathogens identified by the UKHSA, no one could argue with the inclusion of coronaviruses and influenza viruses (the latter being members of the Orthomyxoviridae family).

“The UKHSA are also right to be concerned about another family of viruses, the Paramyxoviridae.  This is a group that includes the measles virus, itself 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.  Such a virus would have a much higher R number 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.  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.  Knowledge, information and data collected in the first few weeks of the next pandemic will be crucial to tailoring our response appropriately.  We need the systems to gather that data in place in advance and ready to be activated, possibly at very short notice.”

‘Priority pathogen families research and development (R&D) tool: A reference tool to help guide England-based funders of research and development’ was published by the UK Health Security Agency at 00:01 UK time on Tuesday 25 March 2025.

Declared interests

Dr Catrin Moore: “No conflicts of interest to declare.”

Prof Jose Vazquez-Boland: “I declare I have no conflict of interest.”

Prof Mark Woolhouse: “I am a consultant for the Coalition for Epidemic Preparedness Innovation (CEPI) and a member of the Scottish Committee for Pandemic Preparedness (SCoPP).”

Prof Martin Hibberd: “I have no conflicts with this topic, but I do work on some of the pathogens listed and have been funded by Industry (most recently J&J) – amongst other government support, to work on them.”

Prof Miles Carroll: “I consult for PicturaBio diagnostics. I am a member of the WHO R&D BluePrint Pathogen Prioritisation Committee, UKVN, APHA SAB and MRC/UVRI SAB.”

Darius Hughes: In December 2023, Moderna entered a 10-year strategic partnership with the UK government to establish an mRNA research development and manufacturing facility in the UK. The strategic partnership is managed by the UK Health Security Agency on behalf of the UK government.

For all other experts, no reply to our request for DOIs was received.