(511f) Characterization of Rabies Virus Vaccine Inactivation

Rabies is an acute, fatal viral encephalitis[1]. It affects a wide range of warm-blooded animals and man. Viral transmission takes place mostly via animal bite. The cause of this fatal disease occurs with intense viral replication in the central nervous system (CNS). After the replication, it spreads to saliva glands. Globally, someone dies every 15 minutes due to rabies[2]. It is argued that rabies is one of the most important viral zoonosis[2]. Presently, measures taken for pre- and post-exposure include wound treatment, vaccine administration and inoculation of rabies immunoglobulin[2]. Most of the RV-Vaccines (RV-Vac) in the market are in lyophilized form. However, RV-Vac could be inactivated drastically after lyophilization and the underlying mechanism of inactivation is not yet understood. It could, for example, cause the disassembly and/or aggregation of the virus or its protein components. Rational stabilization of viruses requires understanding of the mechanism of inactivation as well as the efficacy, stability, feasibility and performance of the vaccine[3,4]. Consequently, stabilization of virally based pharmaceuticals is frequently an empirical procedure based on changes in biological activity rather than the actual inactivation processes themselves. Loss of a very large fraction of its activity is undesirable for two main reasons: One reason is potential immunogenicity, caused for example by viral aggregates as well as glycoprotein G aggregates. A second reason is the loss of the activity itself. In order to understand degradation and therein be able to take better steps to avoid it, we performed a comparative study of the lyophilized and non-lyophilized virus assembly. Specifically, we tested our hypothesis that the vaccine is deactivated by disassembly. To test this hypothesis we employed a multi-analytical approach, which includes TEM, AUC, fluorescence and light scattering techniques.

[1] Sellal, F. and Stoll-Keller, F. (2005). Rabies: ancient yet contemporary cause of encephalitis. The Lancet 365, 921.

[2] Rupprecht, C.E., Hanlon, C.A. and Hemachudha, T. (2002). Rabies re-examined. THE LANCET Infectious Diseases 2, 327-343.

[3] Dietzschold, M.-L., Faber, M., Mattis, J.A., Pak, K.Y., Schnell, M.J. and Dietzschold, B. (2004). In vitro growth and stability of recombinant rabies viruses designed for vaccination of wildlife. Vaccine 23, 518.

[4] Wiktor, T. et al. (1978). Comparison studies on potency tests for rabies vaccines. Developments in Biological Standardization 40, 171-178.