The WHO vaccine prequalification ensures the continued acceptability of vaccines through post-prequalification procedures, including reassessments at regular intervals, targeted testing of lots supplied through UN agencies, and follow-up of complaints from the field and reports of adverse events following immunization (AEFIs). In addition, in order to maintain prequalified status of their products, manufacturers must meet carry out several procedures on an ongoing basis, as well as participate in several procedures focused on testing, reporting, or reassessment. They must also respond to any WHO requests concerning vaccine reassessment or targeted lots testing.

Ongoing commitments

In order to maintain prequalified status of their products manufacturers of prequalified vaccines must:

• retain sample lots for WHO testing
• provide NRA lot-release certificates
• notify WHO of all product changes or variations
• notify WHO of changes to labels or product inserts.

Testing and reporting obligations

Manufacturers must also participate in several post-prequalification procedures that enable WHO to certify that prequalified vaccines being procured by UN agencies continue to meet the required quality standards:

• annual testing of sample lots
• reporting of vaccine quality complaints or adverse events following immunization (AEFIs)
• annual product reporting
• periodic reassessment of product summary files (PSFs). 

Withdrawal from the list of WHO-prequalified vaccines 

In most cases, a product’s prequalified status is withdrawn voluntarily by a manufacturer due to the discontinuation of production or commercialization. In this case, manufacturers must provide WHO with the end of shelf-life date of the last batch produced, so that the vaccine is removed the WHO List of Prequalified Vaccines as soon as the shelf-life expiry date has been reached.

In rare cases prequalified status may be withdrawn by WHO pending further investigation if:

• the manufacturer has not fulfilled it post-prequalification obligations including — but not limited to — provision of lot release certificates or vaccine lot samples when requested by WHO, or notification concerning any product changes or variations or changes to labels and packaging insert
• the manufacturer has not provided documents and information required for product annual review
• the manufacturer has not (fully) complied with the requirements and information requested for periodic product reassessment
• vaccine quality complaints from testing laboratories, or reports of serious adverse events following immunization AEFIs, have been received by WHO.

Note: WHO reserves the right to take appropriate measures, including suspension of supply, initiating a reassessment or withdrawal from the list in the case of noncompliance with post-prequalification commitments and/or in the case of misconduct.

Maintenance fee

A tiered annual maintenance fee is levied for each prequalified vaccine. Details can be found here.