WHO develops a process to determine programmatic suitability of vaccines for prequalification

WHO develops a process to determine programmatic suitability of vaccines for prequalificationby Rudi Eggers, WHO/EPI, and Nora Dellepiane, WHO/QSS The World Health Organization (WHO) recently convened a working group to propose a new process for assessing the programmatic suitability of vaccines for prequalification. The need for a new process has been driven by the emergence of unique vaccine presentations such as relatively large packed volumes, prefilled syringes that do not include an autodisable feature, injection device materials that require nonstandard disposal methods, suboptimal thermostability profiles, and fully liquid low-multidose vials without preservative. These unique vaccine presentations require a more standardized approach for determining programmatic suitability. Like the current process the new process would involve assessing characteristics such as vaccine presentations, labeling, information provided on package inserts, and packaging. The new process, however, explicitly defines the characteristics that determine programmatic suitability and the process for assessing compliance with these characteristics. Important vaccine characteristics would be organized into four groups: mandatory, critical, preferred, and in need of formal review. 1. Mandatory characteristics: Compliance would be compulsory at the time of application for WHO prequalification (screening step) and must be unconditionally met prior to comprehensive review of the product summary file (PSF). 2. Critical characteristics: Compliance with critical characteristics would also be compulsory. However, if upon screening the data the Prequalification (PQ) Secretariat identifies a deviation from a critical characteristic value, then the PQ Secretariat would inform the manufacturer and refer the question for review by a standing committee composed of professionals with programmatic background and expertise to be established by WHO for the purpose. It is proposed to name this committee the Programmatic Suitability for WHO Prequalification (PSPQ) Standing Committee. The PSPQ Standing Committee could then review the information and make a recommendation, with or without consultation with the manufacturer and additional technical experts, to proceed with a comprehensive review of the PSF or to request validation of the acceptability of noncompliant characteristics through additional research. 3. Preferred characteristics: Compliance would be expected. However, deviations could be tolerated (for thermostability and materials characteristics, compliance is encouraged but not expected). 4. Unique, novel, and innovative characteristics: Characteristics not otherwise specified as mandatory, critical, or preferred would be identified by the PQ Secretariat and would be referred to the PSPQ Standing Committee for review, discussion, and recommendation. Reviews of programmatic suitability characteristics are proposed to take place at two points in the process. First, when the application letter is submitted for initial evaluation of the vaccine candidate for prequalification, and second, when the PSF is screened. Once the PSF is found to be suitable for evaluation, the prequalification process includes a review of the production process and quality control procedures, review of clinical data, testing of consistency of lots, and a joint WHO and national regulatory authority site visit to the manufacturing facilities. Once the evaluation is complete and if the vaccine is found to be acceptable, in principle, for purchase, it is considered prequalified and is posted on the WHO website. The prequalification status is valid for a period that varies between two and five years depending on the experience with the vaccine in the market and the performance of the manufacturer. Random lot testing (once per year) provides independent monitoring of continued compliance with the tender specifications. A review of complaints and reports of adverse events following immunization also allows WHO to monitor the performance of the vaccine and detect potential problems and unexpected changes in the characteristics of the vaccine. Once prequalified, United Nations (UN) purchasing agencies have assurance that the vaccine meets WHO standards for quality, safety, and efficacy of vaccines and that the vaccine is appropriate for the intended population and at the relevant immunization schedules. It is the responsibility of the prequalification program to ensure that the candidate vaccines meet WHO recommendations and the needs of the program which are reflected in the UN tender specifications. The tender specifications state the desired features of the vaccines including the stability profile, use of vaccine vial monitors on the vaccine vial, use of temperature monitoring devices during shipment, preferred presentation, labeling and packaging information, packaging volumes, shipment conditions, etc. The proposed PSPQ process will replace a more iterative process that relied solely on individual expert inputs from the WHO PQ Secretariat; the Expanded Program on Immunization team; and the director of the WHO Department of Immunizations, Vaccines, and Biologicals. The proposed PSPQ process will be further circulated for comments and final endorsement by the Expert Committee on Biological Standardization before being formally posted on the WHO website. We invite you to comment on or post a question relating to this article by clicking the “post reply” button on this page. You will have to log in or register; the process is very simple. Return to the Optimize newsletter.