What is animal passage and attenuation?

Animal passage and attenuation are techniques used in virology to study and modify viruses.

Animal passage involves infecting an animal with a virus and then collecting the virus from the animal's tissues or fluids. This process can be repeated multiple times, which can lead to the virus adapting to the animal host and becoming more infectious or virulent. Animal passage can also be used to study the pathogenicity of a virus and to develop animal models of viral diseases.

Attenuation involves deliberately weakening a virus so that it is less harmful or non-infectious. This can be achieved through a variety of methods, such as serial passage in cell culture, heat treatment, or chemical inactivation. Attenuated viruses are often used in vaccines to stimulate an immune response without causing disease.

Animal passage and attenuation are important tools for studying viruses and developing vaccines and antiviral treatments.