Claims for Patent: 4,255,520

Summary for Patent: 4,255,520

Title:	Process for the preparation of a rabies vaccine and vaccine obtained by this process
Abstract:	A method for preparing a rabies vaccine wherein rabies viruses are multiplied in poultry embryos, the heads of the embryos are harvested and the cell extract containing the rabies antigens is separated therefrom for differential centrifugation and density gradient centrifugation, the separated antigen is further processed using conventional methods. This process results in a highly selective concentration of antigens and the production of viruses having a very high activity and freedom from contaminating proteins.
Inventor(s):	Schell; Klaus R. (Flamatt, CH)
Assignee:	Schweizerisches Serum-und Impfinstitut and Institut zur Erforschung der (Bern, CH)
Application Number:	06/136,722
Patent Claims:	1. In a method for the preparation of rabies vaccine wherein rabies viruses are multiplied in poultry embryos, the embryos are harvested and a cell extract containing the rabies antigen is separated therefrom and processed for use, the improvement which comprises harvesting only the heads of the embryos and separating the antigen by differential centrifugation and density gradient centrifugation. 2. The method of claim 1 wherein the embryos are duck embryos, chicken embryos, or quail embryos. 3. The method of claim 1 or 2 wherein the differential centrifugation is carried out at about 10,000 to 15,000 xg and the density gradient centrifugation is carried out at 75,000 to 90,000 xg in increasing sugar concentrations and in buffer solution.

Details for Patent 4,255,520

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Bavarian Nordic A/s	RABAVERT	rabies vaccine	For Injection	103334	10/20/1997		1999-04-10
Sanofi Pasteur Sa	IMOVAX RABIES	rabies vaccine	For Injection	103931	02/04/2000		1999-04-10