The World Health Organization (WHO) is seeking experts to serve as members one of the Shigella Technical Advisory Group (Shigella TAG). This “Call for experts” provides information about the advisory group in question, the expert profiles being sought, the process to express interest, and the process of selection.
Background
Shigella species are among the leading causes of bacterial diarrheal disease globally, contributing significantly to illness and death, especially among young children in low- and middle-income countries (LMICs). The four main species—S. sonnei, S. flexneri, S. dysenteriae, and S. boydii—vary in geographic distribution. S. flexneri predominates in many LMICs, particularly in South Asia and sub-Saharan Africa, while S. sonnei is increasingly common in both transitional and high-income settings. Shigellosis typically presents as acute diarrhea but can result in severe disease and, in rare cases, death—particularly in children under five. In addition to acute illness, both symptomatic and asymptomatic Shigella infections in young children are associated with long-term health consequences such as growth faltering and stunting, which impair physical and cognitive development and increase vulnerability to other infections. Due to limited diagnostic capacity in many regions, the true incidence of Shigella is likely underreported, hindering effective public health responses.
Shigella infections account for a substantial proportion of global diarrheal deaths and Disability-Adjusted Life Years (DALYs), particularly in LMICs. Compounding the public health burden is the growing prevalence of antimicrobial resistance (AMR). Multidrug-resistant (MDR) strains, especially of S. sonnei and S. flexneri, are increasingly difficult to treat, diminishing the efficacy of commonly used oral antibiotics and heightening the urgency for alternative interventions.
While improvements in water, sanitation, and hygiene (WASH) have helped reduce transmission in some settings, such measures alone are insufficient in many high-burden areas. Despite the clear need, there are currently no licensed vaccines against Shigella. However, several promising candidates—ranging from live attenuated to subunit and conjugate platforms—are in various stages of clinical development.
Recognizing the urgent need for prevention tools, the World Health Organization (WHO) has designated Shigella as a priority pathogen for vaccine development, particularly to protect young children in endemic LMICs.
To this end, the establishment of a WHO Technical Advisory Group on Shigella Vaccines (Shigella-TAG) consisting of independent, renowned subject matter experts, will provide expertise and recommendations on the research and development, licensure, and generation of evidence to support policy for the use of standalone or combination Shigella vaccines in LMIC settings, where they are most needed. As such, the remit of this TAG is distinct remit from a future SAGE Working Group that will be needed to prepare for a SAGE policy review, should the clinical trials demonstrate safety and efficacy. The Advisory Group (the “AG”) will act as an advisory body to WHO in the field of Shigella vaccines, including standalone and combination vaccines.
Functions of the Shigella Technical Advisory Group (Shigella TAG)
In its capacity as an advisory body to WHO, the Shigella TAG shall have the following functions:
Review and provide expert technical advice to WHO on Research and Development advances for Shigella vaccines, including identification of research needs and current gaps, product development and formulation, and capacity needs, to ensure candidate products will be successfully positioned for licensure and policy recommendations to meet the public health needs of LMICs;
Review and provide expert technical advice to WHO on the potential refinements to the Preferred Product Characteristics (PPC) for Shigella vaccines, with the goal of informing target product profiles to accelerate vaccine development and licensure, and to reduce the timeframe to vaccine access in LMICs;
Provide independent guidance on the design and conduct of pre-clinical and clinical studies to evaluate the immunogenicity, efficacy and safety profile of Shigella standalone and combination vaccines;
Review and assess the potential challenges, including regulatory, logistical, and financial considerations, associated with the development, production, and distribution of Shigella vaccines, specifically, in the context of LMICs;
Review and make recommendations to WHO on the development of an Evidence Considerations for Vaccine Policy (ECVP), which aims to mitigate introduction delays post-licensure by providing early information on data and evidence that is anticipated to be needed to support country-level, regional and WHO global policy making for Shigella vaccines;
Review and make recommendations to WHO on updated pipeline reviews of standalone and combination Shigella vaccines (when requested by WHO);
Advise the WHO on building consensus among global stakeholders, particularly with respect to product development strategy, including clinical endpoints and regulatory pathways for Shigella standalone and combination vaccines.
Operations of the Shigella TAG
The AG shall normally meet at least once each year. However, WHO may convene additional meetings. AG meetings may be held in person (at WHO headquarters in Geneva or another location, as determined by WHO) or virtually, via video or teleconference. AG meetings may be held in open and/or closed session, as decided by the Chairperson in consultation with WHO.
Open sessions: Open sessions shall be convened for the sole purpose of the exchange of non-confidential information and views and may be attended by Observers (as defined in paragraph III.3 below).
Closed sessions: The sessions dealing with the formulation of recommendations and/or advice to WHO shall be restricted to the members of the AG and essential WHO Secretariat staff.
The AG may decide to establish smaller working groups (sub-groups of the AG) to work on specific issues. Their deliberations shall take place via teleconference or video-conference. For these sub-groups, no quorum requirement will apply; the outcome of their deliberations will be submitted to the AG for review at one of its meetings.
AG members are expected to attend meetings. If a member misses two consecutive meetings, WHO may end his/her appointment as a member of the AG.
A yearly report shall be submitted by the AG to WHO (the Assistant Director-General of the responsible Cluster). All recommendations from the AG are advisory to WHO, who retains full control over any subsequent decisions or actions regarding any proposals, policy issues or other matters considered by the AG.
The AG shall normally make recommendations by consensus. If, in exceptional circumstances, a consensus on a particular issue cannot be reached, minority opinions will be reflected in the meeting report.
Active participation is expected from all AG members, including in working groups, teleconferences, and interaction over email. AG members may, in advance of AG meetings, be requested to review meeting materials and to provide their views for consideration by the AG.
The working language of the group will be English.
Who can express interest?
The Shigella TAG will be multidisciplinary, with members who have a range of technical knowledge, skills and experience relevant to Shigella vaccine development, manufacturing, and clinical evaluation. Approximately 10-15 members may be selected.
WHO welcomes expressions of interest from:
- Scientists, healthcare professionals, and healthcare regulators with expertise the following areas:
- Immunology;
- Microbiology;
- Vaccinology;
- Epidemiology;
- Biostatistics;
- Bioinformatics and Immunoinformatics;
- Molecular biology and Genetics;
- Biochemistry and Structural Biology;
- Regulatory Science;
- Clinical Research;
- Vaccine programmes’ implementation and evaluation;
- National and international vaccine policy;
- Pricing, procurement, needs estimation and/or regulation of vaccines;
- Health systems and programme delivery; and/or
- Ethics, equity, human rights and gender in public health.
Submitting your expression of interest
To register your interest in being considered for the Shigella TAG, please submit the following documents by 21 September 2025 at 24:00h (midnight) Geneva time to vaccines@who.int using the subject line “Expression of interest for the Shigella TAG”:
- A cover letter, indicating your motivation to apply and how you satisfy the selection criteria. Please note that, if selected, membership will be in a personal capacity. Therefore, do not use the letterhead or other identification of your employer;
- Your curriculum vitae (including your nationality/ies) and
- A signed and completed Declaration of Interests (DOI) form for WHO Experts, available at https://www.who.int/about/ethics/declarations-of-interest.
After submission, your expression of interest will be reviewed by WHO. Due to an expected high volume of interest, only selected individuals will be informed.
Important information about the selection processes and conditions of appointment
Members of WHO advisory groups (AGs) must be free of any real, potential or apparent conflicts of interest. To this end, applicants are required to complete the WHO Declaration of Interests for WHO Experts, and the selection as a member of a AG is, amongst other things, dependent on WHO determining that there is no conflict of interest or that any identified conflicts could be appropriately managed (in addition to WHO’s evaluation of an applicant’s experience, expertise and motivation and other criteria).
All AG members will serve in their individual expert capacity and shall not represent any governments, any commercial industries or entities, any research, academic or civil society organizations, or any other bodies, entities, institutions or organizations. They are expected to fully comply with the Code of Conduct for WHO Experts (https://www.who.int/about/ethics/declarations-of-interest). AG members will be expected to sign and return a completed confidentiality undertaking prior to the beginning of the first meeting.
At any point during the selection process, telephone interviews may be scheduled between an applicant and the WHO Secretariat to enable WHO to ask questions relating to the applicant’s experience and expertise and/or to assess whether the applicant meets the criteria for membership in the relevant AG.
The selection of members of the AGs will be made by WHO in its sole discretion, taking into account the following (non-exclusive) criteria: relevant technical expertise; experience in international and country policy work; communication skills; and ability to work constructively with people from different cultural backgrounds and orientations .The selection of AG members will also take account of the need for diverse perspectives from different regions, especially from low and middle-income countries, and for gender balance.
If selected by WHO, proposed members will be sent an invitation letter and a Memorandum of Agreement. Appointment as a member of a AG will be subject to the proposed member returning to WHO the countersigned copy of these two documents.
WHO reserves the right to accept or reject any expression of interest, to annul the open call process and reject all expressions of interest at any time without incurring any liability to the affected applicant or applicants and without any obligation to inform the affected applicant or applicants of the grounds for WHO's action. WHO may also decide, at any time, not to proceed with the establishment of the AG, disband an existing TAG or modify the work of the AG.
WHO shall not in any way be obliged to reveal, or discuss with any applicant, how an expression of interest was assessed, or to provide any other information relating to the evaluation/selection process or to state the reasons for not choosing a member.
WHO may publish the names and a short biography of the selected individuals on the WHO internet.
AG members will not be remunerated for their services in relation to the AG or otherwise. Travel and accommodation expenses of AG members to participate in AG meetings will be covered by WHO in accordance with its applicable policies, rules and procedures.
The appointment will be limited in time as indicated in the letter of appointment.
If you have any questions about this “Call for experts”, please write to vaccines@who.int well before the applicable deadline.