abstract |
(57) Abstract: A method for distinguishing vaccinated and infected animals without the need to kill the tested animals is provided. SOLUTION: An animal afflicted with a virus having a deficiency in at least one gene encoding an antigen of a wild-type ancestor virus is vaccinated with the virus, and then the vaccinated animal and the virulent virus are vaccinated. A method of distinguishing between an animal infected with the virus and an animal vaccinated against the virus, which comprises serologically distinguishing the infected animal without killing the animal. |