Answers to Policy

Answer to “What is the difference between WHO policy and WHO prequalification for TB?”

WHO Prequalification is a product-specific assessment of the performance and quality of an IVD for use in resource-limited settings. The three components are: product dossier review, site inspection, independent laboratory evaluation. It is crucial for ensure a product is manufactured under the quality management system. WHO policy is set differently depending on the department. At the moment, WHO policy usually follows after technologies becoming available, as time is required for the publications to be published in peer-reviewed journals to be included in systematic reviews. The recommendation in each policy should not require updating each time a new technology in the same category e.g. NAAT, enters the market.


Answer to “Is there a WHO prequalification process for TB diagnostics, and if so, how long will the process take?”  

Any manufacturer of a diagnostic that meets a public health need may apply to the WHO requalification programme (PQDx). Each application is processed on a case by case basis. The focus of PQDx usually is on HIV, malaria, viral hepatitis, and now HIV/syphilis dual tests. But if a TB product was to submit for application, WHO PQDs would be happy to review the application.

The length of the process depends on the quality of the submission which may be dictated by a number of factors including the maturation of the quality system at the site of manufacture, the degree of regulatory expertise within the company, etc. This process usually takes no more than 2 years, but manufacturers may approach WHO before design-lock down to ensure the necessary validation and verification studies, and plans for clinical trials that will fulfill WHO requalification requirements.



WHO policy development process for TB dix GRADE

WHO process for evidence, policy, and global implementation of diagnostics, by Weyer et al.  [link]





review of WHO policy


For a review of the WHO policy process for TB diagnostics, please see this presentation by Gilpin et al. [link]




gilpin For a proposed value chain for  policy on new TB diagnostics, see publication by Cobelens et al. [link]




meeting report


For a report of an international meeting on “From data to scale-up: building the evidence base for new TB diagnostics”, please see [link]







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