Vaccine provision: Delivering sustained & widespread use.

The administration of a vaccine to a recipient is the final step in a development and production process that may have begun several decades earlier. Here we describe the scale and complexity of the processes that brings a candidate vaccine through clinical development to the recipient. These challenges include ensuring vaccine quality (between 100 and 500 different Quality Control tests are performed during production to continually assess safety, potency and purity); making decisions about optimal vaccine presentation (pre-filled syringes versus multi-dose vials) that affect capacity and supply; and the importance of maintaining the vaccine cold chain (most vaccines have stringent storage temperature requirements necessary to maintain activity and potency). The ultimate aim is to make sure that an immunogenic product matching the required specifications reaches the recipient. The process from concept to licensure takes 10-30years. Vaccine licensure is based on a file submitted to regulatory agencies which contains the comprehensive compilation of chemistry, manufacturing information, assay procedures, preclinical and clinical trial results, and proposals for post-licensure effectiveness and safety data collection. Expedited development and licensure pathways may be sought in emergency settings: e.g., the 2009 H1N1 influenza pandemic, the 2014 West African Ebola outbreak and meningococcal serogroup B meningitis outbreaks in the United States and New Zealand. Vaccines vary in the complexity of their manufacturing process. Influenza vaccines are particularly challenging to produce and delays in manufacturing may occur, leading to vaccine shortages during the influenza season. Shortages can be difficult to resolve due to long manufacturing lead times and stringent, but variable, local regulations. New technologies are driving the development of new vaccines with simplified manufacturing requirements and with quality specifications that can be confirmed with fewer tests. These technologies could have far-reaching effects on supply, cost of goods, and on response timing to a medical need until product availability. Copyright Â