WHO maintains a robust system to prequalify suitable products and devices for use in immunization programs, according to up-to-date standards. This system ultimately helps safeguard vaccine potency and ensure vaccines are available wherever needed as part of the WHO Expanded Programme on Immunization (EPI).

(Prospective) Prequalification Holders, PQS-accredited laboratories and field test research organizations play a crucial role in meeting and verifying product performance, quality and safety standards.

PQS-accredited testing laboratories are the only competent bodies to carry out any product laboratory evaluation that is required in preparation of a standard product application dossier.

Applicants seeking prequalification may also be required to run field-tests of the performance of their products as a part of their application.

Complete information related to the circumstances of field evaluation, its required stages and the roles and responsibilities of all stakeholders can be found in the IMD-PQS Generic Guide for Field Evaluation, and in the IMD-PQS Standard operating procedure 012: How to field-test a PQS product.

In case of questions, Prequalification Holders and testing laboratories may contact the immunization devices prequalification team. 

When is field-testing required?

Field-testing will always be required for:

• products that require the establishment of a new IMD-PQS category, and for
• products that are based on technologies that are new to the Expanded Programme on Immunization.

Field-testing may also be required where products or devices:

• are safety-critical or are to be used in very large quantities
• require specific tests not covered under existing protocols
• require specific user training acceptance by end-users or operators
• have a history of technical failures.

Applicants should ask WHO whether their product will require field-testing on a case-by-case basis. Field-testing will always require a Study Protocol that has been approved by the IMD-PQS Secretariat in advance of the testing.

Field-testing results must be uploaded to the relevant prequalification application on the WHOs ePQS platform. Field-testing results will not be accepted via email or postal mail as of early 2024.

Responsibilities

Applicants (Prospective Prequalification Holders) are responsible for ensuring the field-testing of products if required by WHO, including:

• identifying an impartial implementing partner
• commissioning a "field-test protocol": including the testing methodology
• covering the costs of the field-test; generally the applicant covers field-test costs, but WHO and/or concerned organizations may do so in special circumstances)
• obtaining national approvals for the field study.

Prospective Prequalification Holders must collaborate and coordinate their field-testing activities, together with:

• WHO PQS
• an independent, impartial technical expert
• EPI programme managers and ministry(ies) of health relevant to the testing location(s)
• technical staff in WHO or UNICEF Country or Regional Offices, as appropriate

Prospective Prequalification Holders must abide by the results and recommendations of the field study.

WHO is responsible for identifying product types for which field-testing is either mandatory or desirable and will specify the appropriate generic testing method for each product type to the manufacturer. WHO is also responsible for approving the study protocol and/or implementing partner, amongst other responsibilities.