RESUMEN
For many years in vivo assays have been a corner stone in safety testing of vaccines for human use. However, there is now an increasing regulatory focus on replacement, reduction and refinement of methods involving animal use. Accordingly, European Pharmacopoeia (Ph.Eur.) monographs and chapters are currently being revised to reduce or discontinue the use of animals in safety and other testing, when such in vivo tests are not absolutely necessary to facilitate risk mitigation. In the current study, a risk assessment of extraneous agents in viral vaccine production has been carried out and it is concluded that only the handling procedures carried out by the technical personnel pose a risk for extraneous viral contamination. A list of named, potentially virulent contaminating viruses, which may have been introduced by these procedures, has been generated. Each of the viruses on this list has been evaluated for possible persistence during the production processes, and it has for all of these been concluded that, if at all present, they only present a negligible risk of introducing extraneous agents in the final product. The overall conclusion of the risk assessment of our vaccine production process is that it justifies the discontinuation of the current in vivo testing, and furthermore demonstrates that there is no need to substitute these in vivo assays with novel in vitro methods.