WHO’s Preferred Product Characteristics (PPCs) and Target Product Profiles (TPPs)
WHO’s Initiative for Vaccine Research (IVR) produces two types of documents to inform vaccine product development: Preferred Product Characteristics (PPCs) and Target Product Profiles (TPPs). PPCs provide strategic guidance as to WHO’s preferences for new vaccines in priority disease areas and are typically developed in early clinical development, prior to phase III clinical trial planning. TPPs provide technical guidance as to WHO’s criteria in response to emergency or epidemic scenarios, and they are developed when there is a commitment to accelerated vaccine development and rapid direction is needed. For this reason, WHO TPPs are usually formulated early in product development, prior to phase I clinical testing. Both documents are intended to articulate the vaccine preferences from an LMIC perspective, with the aim to optimise the global public health impact and suitability of vaccines.
WHO PPCs and TPPs are valued by the vaccine development community because of the effective and broad consultative process that is undertaken to develop consensus with respect to the needs and use case scenarios of vaccines against specific pathogens. Key stakeholders and end-users from various sectors are engaged, whilst considering how these vaccines would offer the greatest public health impact should they become available. The primary target audience for these documents is any entity engaged in global vaccine product development, that is contemplating eventual WHO policy recommendation and prequalification. Therefore PPCs and TPPs are both intended to inform product specific TPPs that are developed by manufacturers and other entities, and to reduce the timeline between vaccine licensure and introduction into countries that have the greatest need.
PPCs and TPPs shape vaccine product development
Although not formal WHO guidelines, PPC and TPP documents have oversight from WHO’s Product Development for Vaccines Advisory Committee, which in turn informs WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) on the status of vaccine development. However, a policy recommendation for vaccine use will ultimately depend on a multitude of factors in addition to product specific attributes, including affordability, cost-effectiveness and the programmatic considerations such as feasibility of implementation and anticipated coverage. Broader perspectives such as equity and community acceptability are also important for health policy.
Product Development for Vaccines Advisory Committee
Description of the WHO’s general processes in support of vaccine development through to evidence-based policy recommendation
IVR collaborates with the WHO R&D Blueprint Initiative on development of TPPs for vaccines against emerging pathogens. Other guidance documents that inform vaccine product development for eventual licensure and uptake in LMICs are described in the ‘Useful Links’ on this page. Collectively, these guidance documents inform stakeholders of WHO preferences for vaccine characteristics, and if considered early in product development, will help to favourably position candidates for policy review that occurs post licensure, thereby accelerating access to vaccines in these contexts.
What is the difference between WHO PPCs and TPPs?
The key difference between TPPs and PPCs is that TPPs contain both minimally acceptable and preferred criteria, whereas PPC contain only preferences. While both documents contain tables of desired product attributes, an additional difference is that PPCs generally contain more narrative guidance than TPPs. In both cases, WHO strives to encourage product innovation and support an end-to-end perspective, linking product development, regulatory, policy and financing perspectives. PPCs tend to list fewer categories of attributes focusing more on a core set including indication, target groups/populations, possible immunization strategies and features of clinical data desired related to safety and efficacy. In recent years, WHO has tended to develop TPPs in the emergency/outbreak vaccine development context, where we wish to provide more granularity on the minimally acceptable criteria. This relates in part to calls from our advisory structures, and governing bodies to develop TPPs for Ebola and Zika vaccines, and more recently for MERS-CoV, Lassa and Nipah vaccines.
WHO TPPs and PPCs differ from manufacturer TPPs in that WHO profiles are pathogen specific but not product specific, whereas manufacturer’s TPPs are usually intended to guide the development of a candidate vaccine development programme.
WHO TPPs and PPCs do not supersede existing WHO guidance on vaccine presentation, packaging, thermostability, formulation and disposal. The specific requirements for vaccines intended for LMIC markets are addressed in documents from the WHO Vaccine Presentation and Packaging Advisory Group (VPPAG):
Guidance on the WHO Prequalification (PQ) process which assesses vaccine quality, safety, efficacy and suitability for use in low and middle-income countries (for Programmatic Suitability for Prequalification (PSPQ) criteria is also available: