Residual bovine serum albumin (BSA) quantitation in vaccines using automated Capillary Western technology

Bovine serum albumin (BSA) is a major component of fetal bovine serum (FBS), which is commonly used as a culture medium during vaccine production. Because BSA can cause allergic reactions in humans the World Health Organization (WHO) has set a guidance of 50 ng or less residual BSA per vaccine dose. Vaccine manufacturers are expected to develop sensitive assays to detect residual BSA. Generally, sandwich enzyme-linked immunosorbent assays (ELISA) are used in the industry to detect these low levels of BSA. We report the development of a new improved method for residual BSA detection using the SimpleWestern technology to analyze residual BSA in an attenuated virus vaccine. The method is based on automated Capillary Western and has linearity of two logs, >80% spike recovery (accuracy), intermediate precision of CV <15%, and LOQ of 5.2 ng/ml. The final method was applied to analyze BSA in four lots of bulk vaccine products and was used to monitor BSA clearance during vaccine process purification.