Influenza pandemic vaccines: the imminent challenges from a technical and regulatory perspective

In 1997, we were ill prepared to produce vaccines in response to the sudden emergence of highly pathogenic H5N1 influenza. This experience stimulated efforts to improve technical and regulatory procedures for pandemic vaccine virus development and, in February 2003, when highly pathogenic H5N1 influenza re-appeared in man, we were able to produce H5N1 vaccine strains by reverse genetics within the space of 3 months. The technical and regulatory progress which made this possible is reviewed and newly developed WHO biosafety risk assessment for vaccine production is described. Recommendations are made for the significant challenges that lie ahead. D 2004 Elsevier B.V. All rights reserved.