Patent ID: 6660513
Filing Date: 2003-12-09
Classification: A61K,A61P,C07K,C12N,Y10S

Abstract:
In a method for attenuating a virus, said virus being culturable in cell culture, said method including the steps of successively replicating said virus through inoculation and replication of the virus in respective individual cell cultures until attenuation is achieved, each of said successive inoculations occurring after cytopathic effect is observed in a previously inoculated cell culture of said respective individual cell cultures, the improvement which comprises removing virus-containing samples from at least certain of said cell cultures while the virus is replicating at a logarithmic rate and prior to induction of cytopathic effects in said certain cell cultures, and inoculating the next respective cell culture passages with said samples, wherein said logarithmic rate refers to the time period in which the virus is replicating exponentially.