Virus inactivation in foetal calf serum by a combined treatment of gamma-irradiation and UV-C irradiation

Transmission of viruses by animal sera like Foetal Calf Serum (FCS) represents a considerable risk for humans and animals particularly when serum is used for production of pharmaceutical products such as vaccines. Procedures applicable for inactivating large numbers of different viruses both enveloped and non-enveloped, are therefore mandatory. The most used Gamma irradiation method accepted by FDA and EU guidelines efficiently abolish most of enveloped viral contaminants whereas "non-enveloped" viruses (e.g. Bovine Parvovirus) are not fully eliminated. For this purpose we have developed and validated UV-C irradiation in combination with Gamma irradiation as an efficient virus-inactivation method. Spiking experiments in FCS were performed and revealed constantly high clearance rates for various viruses such as bovine parvovirus, parainfluenza type III virus, bovine diarrhoe virus and different forms of mycoplasmas. Experimental data showed that the combined UV-C and Gamma-treated sera maintained their growth promoting activities for various cell types. The validated process of UV-C treated FCS possesses a high inactivation capacity for the "non-enveloped" parvoviruses, a pathogen that cannot be destroyed easily by the Gamma irradiation alone. The UV inactivation procedure was performed with a novel computerised equipment. Only the combined irradiation of serum with Gamma and UV light offers under validated and controlled cGMP conditions the maximum possible raw material safety for biopharmaceutical production.