Extra-ordinary review

If serious problems arise with a prequalified product that may put vaccine potency at risk, the IMD-PQS Secretariat may deem an extra-ordinary review process to be necessary. the Prequalification Holder must provide all information requested of them. 

An extra-ordinary prequalification review will take place immediately if:

• major changes have been made to the product
• the Prequalification Holder has failed to notify WHO of complaints received about the product that may put vaccine potency at risk (product feedback should be provided via the performance & complaints form
• UN agencies or product users have reported receipt of non-compliant products
• complaint investigations have indicated significant quality or safety defects.

Additional sources of information during review

The following additional sources of information may be taken into consideration during product re-evaluation:

• UNICEF Supply Division Quality Assurance Centre reports
• results of structured field performance monitoring
• performance feedback from governments and donor agencies
• Prequalification Holders' change notifications
• Prequalification Holders' product defect reports
• questionnaires
• anecdotal reports from the field
• relevant policy decisions.