(Dr. Wang) Definition of herd immunity is

(Dr. Yan) Prion will lose the infectivity after they released into the environment. 

Susceptible cells have functional receptor for a given virus, may or may not support viral replication.

True or false:  stimulation of the immune response can make disease due to porcine circovirius-2 infection worse.

(Dr. Wang) Which of the following hosts can be infected by vesicular stomatitis virus?

The early infection in utero with a non-cytopathic strain of bovine viral diarrhea virus has this effect on the immune response:

(Alejandro Banda) These viruses are ubiquitous in commercial poultry, they can be transmitted both vertically and horizontally, and they may induce viral arthritis and runting-stunting/poor absorption in chickens:

(Alejandro Banda) This virus has been identified in Eastern U.S. It is close related to WEEV, it is transmitted by Culisetta melanura with songbirds in freshwater swamps as reservoirs. Can produce sporadic encephalitis in horses and disease in chukar partridges, and turkeys.

(Dr. Yan) The common cause of caliciviruses is upper respiratory tract infections, which can be lifelong with ongoing shedding of virus.

(Dr. Wang) Rabies virus causes intra nuclear inclusions in the soma of the medullary ganglia.