WHO informal consultation on the guidelines for evaluation of the quality, safety, and efficacy of DNA vaccines, Geneva, Switzerland, December 2019.

Consultations have been held to promote the revision of the WHO guidelines for assuring the quality and nonclinical safety evaluation of DNA vaccines adopted by the Expert Committee on Biological Standardization (ECBS) in 2005. The drivers for this revision are described, including the need for regulatory convergence highlighted by the WHO R&D Blueprint. These consultations have driven the revision to its current form, where a new guideline that includes quality, nonclinical, and clinical evaluation of plasmid DNA vaccines is being prepared for public consultation with a view to present to an upcoming ECBS. Major changes to the guidelines include streamlining the existing quality (part A) and nonclinical (part B) sections to reflect the two decades of experience, with manufacturing and control, nonclinical evaluation, and clinical testing of plasmid DNA vaccines, as a platform technology. The urgency for gaining regulatory convergence on this topic is that development of such a platform technology as DNA vaccines for routine use immunizations will prepare manufacturers and regulators across the globe in dealing with rapid development of medical countermeasures against emerging infectious diseases even in the face of an emergency setting. Two examples are described of Zika candidate vaccines that have rapidly advanced in development based on preexisting nonclinical and clinical data that precluded the need to repeat nonclinical toxicology. This report describes the progress stemming from the most recent consultation on the guidelines, including topics discussed and consensus reached.