Biological Standards Commission Archives - WOAH - World Organisation for Animal Health

WOAH is launching a call for nominations to establish a list of experts from which the World Assembly of Delegates will elect members and nominate Presidents and Vice Presidents to its four Specialist Commissions.

The call opens on 6 July and closes on 11 September 2026.

The Specialist Commissions are:

Aquatic Animal Health Standards Commission

Biological Standards Commission

Scientific Commission on Animal Diseases

Terrestrial Animal Health Standards Commission

Are you a potential candidate?

WOAH invites internationally recognised veterinarians or experts with strong technical knowledge and practical experience in terrestrial or aquatic animal health and welfare to apply.

You should:

have demonstrated expertise in animal health and welfare, as well as in veterinary public health.

be highly proficient in English (listening, reading, speaking and writing).

have good communication and analytical skills to work in an intercultural environment.

be able to secure endorsement from your WOAH Delegate and support from your employer.

commit the time needed to participate in the work programme and attend meetings in Paris between May 2027 and May 2030.

How to apply

Before submitting your application:

Confirm your eligibility and ensure you meet the required expertise and availability (see full guidance).

Obtain a letter of endorsement from the Delegate of your native country or your country of residence (consult the list of WOAH Delegates).

Prepare your application, demonstrating how you meet the evaluation criteria – described in the Annex III of the Guidance – by providing your professional competencies (qualifications, international standards, scientific technical expertise) and key attributes (communication and analytical skills, intercultural awareness and teamwork skills), as well as your proficiency in English (see requirements).

About the Specialist Commissions

WOAH Specialist Commissions play a key role in developing and revising international standards, collaborating with the Organisation’s global scientific network. They are also responsible for the official recognition of animal health status and provide scientific and technical advice on epidemiology, prevention and control of animal diseases (see Specialist Commissions and Internal Rules, Terms of Reference of the WOAH Specialist Commissions).

Learn more

For futher information, consult the Frequently Asked Questions, visit the dedicated webpage www.woah.org/callforexperts or contact: [email protected]

Important information

Only applications submitted through the online system will be accepted.

Incomplete applications cannot be saved; applicants are advised to prepare their responses in advance and paste them into the online form when ready to submit (see Annex IV of the Guidance).

Applications received after the deadline will not be considered.

WOAH Biological Standards Commission decides to relaunch a global call for new tuberculin candidates after extensive international trials

Following a decade of international studies, the WOAH Biological Standards Commission, supported by an ad hoc group of experts, has concluded that the proposed replacement candidates for the International Standard for Bovine Tuberculin do not meet the required potency levels. It will now relaunch a global call for new candidates’ materials.

What is the International Standard for Bovine Tuberculin?

The International Standard Bovine Tuberculin (ISBT) is a biological reference material derived from Mycobacterium bovis strain AN5. Established nearly three decades ago, it defines a standardised protein concentration that serves as the global benchmark for tuberculin potency testing.

ISBT is used worldwide in bovine tuberculosis control programmes for screening cattle. All commercial bovine tuberculin preparations must be calibrated against this standard.

The science behind tuberculin testing

Tuberculin testing exploits the immune system’s memory of infection. When Mycobacterium tuberculosis complex organisms infect cattle, the animal’s immune system develops a hypersensitivity response to specific bacterial proteins. The tuberculin skin test capitalises on this biological activity by injecting purified protein derivative (PPD) intradermally and measuring the resulting immune response as an increase in skin thickness. This delayed hypersensitivity reaction, measured 72 hours post-injection, indicates prior exposure to tuberculosis.

A decade-long effort to replace the standard

The current ISBT, established in 1986, has been in limited supply since 2015. In response, WOAH’s Biological Standards Commission, supported by an ad hoc group of mammalian tuberculosis reference laboratory experts, has coordinated experiments with multiple laboratories, research institutes and tuberculin manufacturers across continents to identify a suitable replacement.

Key findings

Two candidates were initially shortlisted in 2017. Following further evaluation, only one (Candidate B) progressed to international collaborative trials conducted between 2018 and 2025.

However, the latest assays revealed persistent potency shortfalls:

Potency levels (18,000–19,116 IU/mg) remained well below the required minimum of 32,000 IU/mg.

Multiple laboratories confirmed inconsistent results despite protocol refinements.

High assay variability and weak dose-response relationships hindered reliable potency determination.

Final trials in November 2025 confirmed that Candidate B does not meet the criteria to replace ISBT.

Future directions

The Biological Standards Commission acknowledged that PPD is a complex biological substance having many specific and non-specific proteins. They emphasised that accepting a lower potency international standard would compromise the comparability of global tuberculin standardisation across laboratories and batches.

The Commission therefore decided to:

relaunch a global call for new tuberculin candidates.

support the development of alternative approaches for PPD-based tests such as the Molecularly Defined Tuberculins (MDTs) which use specific peptides as a long-term alternative to traditional PPD-based assays.

While promising, MDTs require further field validation across different epidemiological settings before they can replace current methods.