VALIDATE Workshop: Vaccines for Neglected Tropical Skin Diseases – Progress and Challenges

Workshop Report

Vaccines for Neglected Tropical Skin Diseases  - Group Photo

 

From 6–8 May 2025, the VALIDATE Network hosted a closed workshop in Bogotá, Colombia, bringing together 28 invited delegates to tackle one of global health’s more overlooked challenges: vaccine development for neglected tropical skin diseases (NTDs). Held at the elegant Museo El Chicó, the workshop focused on leishmaniasis, Buruli ulcer, leprosy, and cutaneous tuberculosis—diseases which share common immunological features but are often sidelined in global vaccine R&D.

 

 

Day One: Introductions

Dr Maria Adelaida Gomez opened the workshop by highlighting the renewed momentum behind skin-NTD research and the potential for collective action. The morning continued with short “Turbo Talks,” during which each delegate introduced themselves, their work, and their expectations for the workshop. The quick-fire talks set a collaborative tone for the rest of the workshop..

The workshop opened with a welcome from Dr Maria Adelaida Gomez (CIDEIM, Colombia), who set the tone for three days of collaborative and interdisciplinary dialogue. The initial session featured “Turbo Talks,” in which all delegates gave short introductions to their work, helping to build connections across a diverse group of attendees and laying the groundwork for meaningful engagement.

The first morning focused on foundational overviews of the four main pathogens. Dr Gomez began with a talk on the wide clinical spectrum of cutaneous leishmaniasis and the challenges this diversity poses for vaccine development. She was followed by Prof Steve Muhi (University of Melbourne, Australia), standing in for Dr Yaw Ampem Amoako (KNUST & KCCR, Ghana), who presented an overview of Buruli ulcer disease and highlighted the shifting epidemiology and lack of vaccine tools. Dr Hua Wang (University of Strathclyde, UK) gave a historical and scientific overview of Mycobacterium leprae, while Prof Rajko Reljic (St George’s University of London, UK) offered a brief presentation on tuberculosis with a focus on its cutaneous forms. These sessions provided a shared knowledge base that would support comparative discussions later in the programme.

The afternoon moved to funders' and organisational perspectives. Dr Sundeep Vedithi (University of Cambridge, UK) discussed the development of point-of-care diagnostics and LepVax, a promising leprosy vaccine candidate. Jeanette Hayes (Wellcome Trust, UK) shared Wellcome’s current investments and future priorities in infectious disease research, with emphasis on TB and leishmaniasis. Luis Calzadilla (British Embassy, Colombia) provided an overview of the UK’s Science and Technology portfolio in Colombia, and Dr Daniel Argaw Dagne (World Health Organization, Switzerland) spoke on the integrated management of skin NTDs and key research gaps. The day concluded with a round-table discussion addressing the role of funders in raising disease awareness, monitoring project impact, prioritising vaccine targets, and forming effective public-private-academic partnerships.

 

Comment from a delegate.

 

Day Two: Pathogenesis & Vaccines in the Field

Day two focused on pathogenesis, immune mechanisms, and vaccine innovation. The morning began with Dr Fernanda Novais (Ohio State University, USA), who examined how immune responses in cutaneous leishmaniasis can drive tissue damage rather than parasite clearance. Prof Rachel Simmonds (University of Surrey, UK) followed with a talk on the virulence factor mycolactone and its disruptive effects on host cellular physiology in Buruli ulcer. Dr Márcia Rodrigues Jardim (Fiocruz, Brazil) spoke about the pathogenesis of leprosy and the critical importance of early diagnosis, especially in relation to peripheral nerve damage. Prof Adrie Steyn (Africa Health Research Institute, South Africa, and University of Alabama, USA) then presented detailed insights into human TB lesions using cutting-edge spatial transcriptomics and multiplex imaging. These talks were followed by a round-table session that explored shared and divergent immunological mechanisms across the skin NTDs, the role of systems biology, and the potential of interdisciplinary collaboration to advance understanding of host-pathogen dynamics.

The afternoon turned to recent progress in vaccine research. Prof Rajko Reljic presented data from his team’s recent work showing that a composite subunit vaccine conferred full protection against Mycobacterium ulcerans in a mouse model. Dr Camila de Oliveira (Fiocruz, Brazil) discussed the use of attenuated parasites in developing a vaccine for Leishmania braziliensis, while Dr Veronica Schmitz Pereira (Fiocruz, Brazil) reviewed the progress of a leprosy vaccine currently undergoing clinical trials and the challenges of identifying reliable correlates of protection. Round-table discussion topics included the feasibility of cross-protective vaccines, the potential for mRNA technologies in NTD contexts, and the likely impact of climate change on disease spread and research priorities.

 

Comment from a delegate.

 

Day Three: Modelling and Social Perspectives

The final day opened with a session on laboratory and animal models. Prof Steve Muhi returned to discuss the evolution of Buruli ulcer animal models, including upcoming plans to trial vaccines in native Australian possums. Prof Manabu Ato (National Institute of Infectious Diseases, Japan) explored the limitations of current models for leprosy and the translational efforts underway in his lab. Dr Andres Felipe Vallejo Pulido (University of Southampton, UK) presented on spatial and single-cell transcriptomics as tools for decoding local immune responses and informing antigen selection and delivery system design. The accompanying round-table addressed the future of in vitro and ex vivo systems, how human trial outcomes could be better used to refine models, and whether partially protective vaccines should continue to be pursued.

The final session turned to the social aspects of skin NTD research. Prof Maria Elena Bottazzi (Baylor College of Medicine, USA) offered a framework for integrating vaccine science with economic and policy considerations. Mrs Alexandra Cossio Duque (CIDEIM, Colombia) addressed the logistical and ethical challenges of conducting clinical research in remote rural areas. Dr Maria del Mar Castro Noriega (University of Heidelberg / CIDEIM) discussed the role of qualitative and mixed-methods research in incorporating patient perspectives into product development. Mrs Maria Isabel Echavarria (CIDEIM, Colombia) focused on implementation science and social innovation as tools to translate interventions into real-world impact, and Dr Krishna Lama shared lessons from leprosy control efforts that used community-led models of engagement.

The final round-table discussions focused on incorporating patient perspectives into policy and product development, measuring vaccine impact beyond clinical outcomes, addressing vaccine hesitancy, and ensuring equitable access in low-income settings. Delegates also considered next steps for collaboration, including developing a joint white paper, forming thematic working groups, delivering an online seminar series, or co-authoring a poster for the VALIDATE Annual Meeting.

 

How delegates described the workshop.

 

Vaccines for Neglected Tropical Skin Diseases – Progress and Challenges - Feedback Word Cloud

 

 

 

Agenda

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 0845 – 0900  Registration & Coffee

0900 – 0905  Welcome from Dr Maria Adelaida Gomez

 

Session 1: Introductions

 

0905 – 1020  Turbo Talks

All Delegates

 

 

1020 – 1050  Break

 

1050 – 1120  The Cutaneous Leishmaniasis Spectrum and Challenges for Vaccine Development

Prof Maria Adelaida Gomez, CIDEIM, Colombia

 

 

1120 – 1150  Overview of Buruli Ulcer Disease

Dr Stephen Muhi, University of Melbourne, Australia (standing in for Dr Yaw Ampem Amoako, KNUSTKCCR, Ghana)

 

 

1150 – 1200  Q&A / Panel

1200 – 1300  Lunch

 

1300 – 1330  Leprosy: What Do We Know About Mycobacterium leprae?

Dr Hua Wang, University of Strathclyde, UK

 

 

1330 – 1400  Brief Overview of TB with a Focus on Cutaneous Forms

Prof Rajko Reljic, St George's University of London (SGUL), UK

 

 

1400 – 1410  Q&A / Panel

 

1410 – 1440  Break

 

Session 2: Funders & Organisation Perspectives

 

1440 – 1500  Advancements in Point-of-Care Molecular Diagnostics and Vaccine Strategies for Leprosy Diagnosis and Control

Dr Sundeep Vedithi, University of Cambridge, UK

 

 

1500 – 1520  Wellcome's Strategic Approach to Infectious Disease Challenges

Miss Jeanette Hayes, Wellcome Trust, UK

 

 

1520 – 1540  UK Science & Technology Network in Colombia

Mr Luis Calzadilla, British Embassy, Colombia

 

 

1540 – 1600  Integrated Control and Management of Skin NTDs and Priority Research Gaps

Dr Daniel Argaw Dagne, World Health Organization (WHO), Switzerland

 

 

1600 – 1620  Q&A / Panel

1620 – 1655  Round-table Discussions

1655 – 1700  Wrap-Up

0845 – 0900  Registration & Coffee

0900 – 0905  Welcome from Dr Maria Adelaida Gomez

0845 – 0900  Coffee

 

Session 3: Pathogenesis – Mechanisms of Protection, Pathology, Virulence Factors

 

0900 – 0930  Immunopathogenesis in Cutaneous Leishmaniasis

Dr Fernanda Novais, Ohio State University, USA

 

 

0930 – 1000  Inhibition of Sec61 by Mycolactone – A Virulence Mechanism with Major Impacts on Cellular Physiology

Prof Rachel Simmonds, University of Surrey, UK

 

 

1000 – 1010  Q&A / Panel

1010 – 1040  Break

 

1040 – 1110  Leprosy: History, Pathogenesis, and Treatment

Dr Márcia Rodrigues Jardim, Fundação Oswaldo Cruz (Fiocruz), Brazil

 

 

1110 – 1140  Unmasking Human Tuberculosis: Insights into Granuloma Biology and Disease Pathogenesis

Prof Adrie Steyn, AHRI & University of Alabama, South Africa & USA

 

 

1140 – 1150  Q&A / Panel

1150 – 1230  Round-table Discussions

1230 – 1330  Lunch

Session 4: Latest Vaccine Progress in the Field

 

1330 – 1400  A Composite Subunit Vaccine Confers Full Protection Against Buruli Ulcer in the Mouse Model

Prof Rajko Reljic, St George's University of London (SGUL), UK

 

 

1400 – 1430  Attenuated Parasites as a Road for Vaccine Development Against CL – Roadblocks and Advancements

Dr Camila de Oliveira, Fundação Oswaldo Cruz (Fiocruz), Brazil

 

 

1430 – 1500  Advancing Leprosy Vaccines Through Human Immunology: Challenges and New Directions

Dr Veronica Schmitz, Fundação Oswaldo Cruz (Fiocruz), Brazil

 

 

1500 – 1515  Q&A / Panel

1515 – 1545  Break

1545 – 1645  Round-table Discussions

1645 – 1700  Wrap-Up

0845 – 0900  Coffee

Session 5: Lab & Animal Models to Study Local Immune Responses and Delivery Systems

 

0900 – 0930  Buruli Ulcer Vaccine Animal Models: Past, Present and Future Challenges

Prof Steve Muhi, University of Melbourne, Australia

 

 

0930 – 1000  Basic and Translational Research for Leprosy: A Long Road to Prevention, Diagnosis, and Therapeutics

Prof Manabu Ato, National Institute of Infectious Diseases (NIID), Japan

 

 

1000 – 1030  Spatial & Single Cell Transcriptomics: Decoding Skin Resident Immunity from Melanoma to Mycobacteria

Dr Andres Vallejo, University of Southampton, UK

 

 

1030 – 1045  Q&A / Panel

1045 – 1115  Break

1115 – 1200  Round-table Discussions

1200 – 1300  Lunch

Session 6: Social Aspects – Patient Perspectives and Societal Impact

1300 – 1320  Integrating the Vaccine Sciences within Social, Economic, and Policy Perspectives

Prof Maria Elena Botazzi, Baylor College of Medicine, USA

 

 

1320 – 1340  The Social Challenges of Clinical Research in Skin NTDs in Remote Rural Areas

Mrs Alexandra Cossio, CIDEIM, Colombia

 

 

1340 – 1400  Patient Involvement in Leishmaniasis Product Development: The Role of Qualitative and Mixed Methods

Dr Maria del Mar Castro, University of Heidelberg / CIDEIM

 

 

 

1400 – 1420  Bridging the Gap: From Intervention to Impact Through Implementation Research and Social Innovation

Mrs Maria I Echavarria, CIDEIM, Colombia

 

 

 

1420 – 1500 Q&A / Panel

1500 – 1530  Break

1530 – 1635  Round-table Discussions

1635 – 1700  Wrap-Up