This report presents the recommendations of a WHO expertcommittee commissioned to coordinate activities leadingto the adoption of international recommendations for theproduction and control of vaccines and other biologicalsand the establishment of international biological referencematerials. Following a brief introduction the report summarizes anumber of general issues brought to the attention of theCommittee. The next part of the report of particular relevanceto manufacturers and national regulatory authorities sets outrevised WHO Guidelines on the quality safety and efficacyof candidate dengue tetravalent vaccines (live attenuated) along with revised WHO Recommendations in relation to theproduction and quality control of bacille Calmette-Guérin(BCG) vaccines and of acellular pertussis vaccines. In addition a generic protocol for the calibration of seasonal and pandemicinfluenza antigen working reagents is included. Revised WHOGuidelines for thromboplastins and plasma used to controloral anticoagulant therapy with vitamin K antagonists are thenpresented. Finally new WHO assessment criteria for nationalblood regulatory systems are provided. Subsequent sections of the report then provide information onthe current status and proposed development of internationalreference materials in the areas of antibiotics; biotherapeuticsother than blood products; blood products and relatedsubstances; in vitro diagnostic device reagents; and vaccinesand related substances. A series of annexes are then presented which include anupdated list of WHO Recommendations Guidelines andother documents on biological substances used in medicine(Annex 1) followed by a series of WHO Recommendationsand Guidelines adopted on the advice of the Committee(Annexes 2-7). All additions made during the meeting tothe list of International Standards and Reference Reagentsfor biological substances maintained by WHO are thensummarized in Annex 8.