Skip to content
Briefings are running a touch slower this week while we rebuild the foundations.See roadmap
Pandemics and Biosecurity
24MAY

WHO publishes three Q1 pathogen-family roadmaps

4 min read
16:06UTC

The WHO R&D Blueprint published Filovirus, Arenaviridae and Paramyxovirus medical-countermeasure roadmaps in Q1 2026, with public consultations open through late May.

ScienceDeveloping
Key takeaway

Family-level R&D roadmaps consolidate Disease-X funding around platforms with cross-protective potential rather than narrow single-pathogen bets.

The WHO R&D Blueprint published three pathogen-family roadmaps in Q1 2026: Filovirus on 3 March (covering Ebola and Marburg), Arenaviridae on 12 March (covering Lassa, Junin and other haemorrhagic fevers), and Paramyxovirus on 31 March (covering Nipah, Hendra and measles). Public consultations on all three remain open through late May, with input invited from research institutes, regulators, industry and national authorities.

The family-level shift matters because of how single-pathogen plans tend to fail. A Lassa roadmap concentrates capacity on Lassa-specific antigens, animal models and assay platforms, and leaves a research base poorly equipped when a Junin or Machupo variant surfaces. The arenavirus family shares enough viral biology that a platform tuned to Lassa, with the right adjustments, can be repurposed faster than starting from scratch; the same logic runs for the henipaviruses inside the Paramyxovirus group, where a Nipah vaccine candidate offers a head start against a future Hendra-like emergence. Family roadmaps formalise that logic and direct funders toward platforms with cross-protective potential rather than narrow single-pathogen investments.

The Arenaviridae roadmap is the one that lands closest to the rest of this briefing. Argentina carries both the Andes virus strain at the heart of the MV Hondius cluster in Patagonia and Junin virus in the Pampas grain belt, which together make the country one of the densest zoonotic-spillover environments on the public record. A coordinated arenavirus-and-hantavirus medical-countermeasure programme in Argentina would link surveillance, sample collection and clinical-trial capacity that currently sits in three separate ministries. The roadmap creates the funding rationale for that coordination, even if the consolidation itself is a national rather than a WHO decision.

Public input on all three roadmaps closes in late May 2026, after which the World Health Organization moves to finalisation and CEPI, GAVI and national funders begin matching pipeline calls to roadmap priorities. National research councils that miss the consultation window forfeit influence on the funding cascade that follows. The roadmaps themselves are not vaccines; they are the upstream prioritisation document that determines which candidates reach Phase 1 in the next funding cycle. Whether they translate into product depends on the same supply-chain, manufacturing and regulatory machinery now under stress in the H5N1 programme. The structural risk to watch is that the roadmaps become reference documents rather than money flows.

Deep Analysis

In plain English

The WHO runs a programme called the R&D Blueprint, which is essentially a list of the pathogens most likely to cause a future pandemic and a plan for how to develop vaccines and treatments for each of them before that happens. In early 2026, it published three new roadmaps covering whole families of viruses: the Filovirus family (including Ebola and Marburg), the Arenaviridae family (including Lassa fever), and the Paramyxovirus family (including Nipah). The idea is that the science needed to make a vaccine for Ebola has a lot in common with the science for Marburg, because they are related viruses. By building roadmaps at the family level, the WHO hopes researchers can share tools and approaches, rather than starting from scratch for each new outbreak.

Deep Analysis
Root Causes

The WHO Blueprint programme was established in 2015 following the West Africa Ebola outbreak, which exposed the absence of any pre-positioned medical countermeasure development pathway for pathogens with high mortality but historically limited commercial market.

The Blueprint's priority pathogen list and roadmap architecture are periodically reviewed; the Q1 2026 tranche of three roadmaps reflects the post-COVID review cycle that formally concluded in 2023-24 and produced revised criteria for pathogen family selection.

Argentina's dual burden, hantavirus Andes virus in Patagonia and Junin virus in the Pampas grain belt, makes it one of the world's more significant zoonotic hotspot countries and gives the Arenaviridae roadmap particular relevance to the current week's events. The Arenaviridae family covers both Junin (the cause of Argentine haemorrhagic fever) and Lassa fever in West Africa, making the roadmap structurally relevant to two of the world's most economically disadvantaged disease-burden regions.

What could happen next?
  • Opportunity

    Public consultations on all three roadmaps remain open through late May 2026; research institutions, biotech companies, and national health agencies can submit evidence and priorities that will shape CEPI and WHO funding allocations for the next 2-3 years in each family.

    Immediate · 0.9
  • Consequence

    The Arenaviridae roadmap, which covers Junin virus, creates an international research mandate for Argentine haemorrhagic fever countermeasures that aligns with Argentina's domestic biosecurity burden and could attract CEPI co-financing for Junin vaccine development.

    Medium term · 0.55
  • Risk

    If the specific pathogen that emerges as the next pandemic threat falls within one of the three newly-roadmapped families but diverges significantly from the antigen constructs the roadmap prioritises, the family-level strategy provides incomplete preparation compared with a more targeted pathogen-specific programme.

    Long term · 0.4
First Reported In

Update #1 · Hantavirus comes ashore; H5N1 won't quit

World Health Organization· 7 May 2026
Read original
Different Perspectives
European Union / ECDC
European Union / ECDC
ECDC activated an EU Health Task Force, assessed European Bundibugyo import risk as very low, and flagged the recombinant clade Ib/IIb mpox strain in four countries as a surveillance watch item. Both calls reflect the same post-2024 IHR mandate: ECDC acts as a continental early-warning layer rather than waiting for WHO Disease Outbreak News guidance.
Ituri and South Kivu communities / DRC
Ituri and South Kivu communities / DRC
Residents in South Kivu torched a treatment facility when response teams arrived, a signal of community trust deficit that a no-state-apparatus response cannot overcome before it can begin. In Ituri, four healthcare worker deaths at Mongbwalu General Referral Hospital in four days reflect the population's first line of care bearing the outbreak's worst nosocomial burden without species-specific equipment or treatment.
Uganda / Diana Atwine
Uganda / Diana Atwine
Atwine confirmed two imported Bundibugyo cases in Kampala with no onward spread, deployed a mobile laboratory to Kasese on the DRC border, and placed 25 contacts under monitoring before any IHR Temporary Recommendations existed. Uganda's response demonstrates that containment is achievable where a functioning state health authority can compel and protect.
Africa CDC / Jean Kaseya
Africa CDC / Jean Kaseya
Kaseya declared a continental emergency 24 hours before the WHO PHEIC and publicly opposed the US entry ban on 19 May, arguing it punishes countries by passport rather than exposure history. The declaration, Africa CDC's second consecutive pre-WHO move after the 2024 mpox sequencing, reflects an AU strategy to lead early-phase responses independently of Geneva.
United States / HHS
United States / HHS
Washington imposed a 21-day entry ban on nationals of DRC, Uganda and South Sudan on 18 May, including green-card holders, and began enhanced screening for US citizens at George Bush Intercontinental Airport in Houston from 26 May. The ban predated WHO Temporary Recommendations by four days and covered South Sudan despite zero confirmed cases there.
Tedros Adhanom Ghebreyesus / WHO
Tedros Adhanom Ghebreyesus / WHO
Tedros declared the PHEIC on 17 May without the IHR Emergency Committee, then watched the committee's 22 May no-travel-restriction advice arrive four days after the US ban it was meant to prevent. A declaration without operational instructions left states parties with the headline of a global emergency but no guidance on screening, trade or deployment.