REFERENCE-STANDARDS FOR VACCINE-PRODUCING LABORATORIES

The inherent variability of the biological systems used for production of vaccines is much greater than that encountered in the production o f pharmaceuticals. Therefore, producers of vaccines must take particul ar care to Ensure that the different batches of a vaccine are of reaso nable consistency and that the immunising activity of each batch is eq uivalent to that of the vaccine originally shown to he effective in th e target species. Th is struggle for consistency has been the main mot ive for developing the range of reference standards which serve as fix ed reference points during the production and quality control of a vac cine.