Who Guidelines on Clinical Evaluation of Vaccines: Regulatory Expectations

The text is written in the form of guidelines instead of recommendations in view the fact that vaccines represent a heterogeneous class of agents, and the preclinical and clinical testing programmes will need to be adapted for the product in question. Guidelines allow greater flexibility than Recommendations with respect to specific issues related to particular vaccines. A separate WHO document is under development to provide more detailed guidance on preclinical and laboratory evaluation of vaccines. The section of this document that discusses preclinical and laboratory evaluation consequently provides general guidance but does not define international regulatory expectations in this area.