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).

Product manufacturers, 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.

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

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

When is field-testing required?

WHO may require manufacturers to field-test the performance of a product or device in its intended operating environment if it:

• is safety critical or will be used in very large quantities
• is based on technology(ies) new to WHO or to immunization programmes
• requires specific tests not covered by existing protocols
• requires establishment of a new category
• requires specific user training acceptance by end-users or operators
• has a history of technical failures.

Field-testing provides manufacturers with information to improve product design. It can also help end-users to select products that are best suited to their needs and operating environments.

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.

Responsibilities

Manufacturers 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 manufacturer covers field-test costs, but WHO and/or concerned organizations may do so in special circumstances)
• obtaining national approvals for the field study.

Manufacturers 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

and 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.

A detailed list of the responsibilities of the different parties can be found in PQS Standard operating procedure 012: How to field test a PQS product.