Biometrical aspects in the design and analysis of chimpanzees trials assessing hepatitis virus inactivation.

Hepatitis virus safety of products derived from blood is achieved by screening of individual blood donations and by production processes efficient in eliminating and inactivating residual amounts of hepatitis viruses. A quantitative measure of process inactivation efficiency is the inactivation factor derived from process overchallenging experiments. A product is safe if the corresponding process inactivation factor is as high as the one of a product whose safety has been clinically established. Reliable information on hepatitis safety cannot be obtained by testing commercial end product samples in chimpanzees.