therefore unless a marked and activated baccine that is a vaccine of which the pathogenic organism of vaccine origin is developed an impossible vaccinated animal an animal infent
Therefore, unless a marked inactivated vaccine that is, a vaccine of which the pathogenic organism is of vaccine origin is developed, it will be impossible to distinguish between a vaccinated animal and an animal infected by the virus.
Therefore, unless a marked inactivated vaccine that is, a vaccine of which the pathogenic organism of vaccine origin is developed, it impossible vaccinated animal and animal infected by the