A slow virus disease is a disease that, after an extended period of latency, follows a slow, progressive course spanning months to years, frequently involves the central nervous system, and in most cases progresses to death.
Examples of slow virus diseases include HIV/AIDS, caused by the HIV virus,[1] subacute sclerosing panencephalitis, the rare result of a measles virus infection,[2] and Paget's disease of bone (osteitis deformans), which may be associated with paramyxoviruses, especially the measles virus and the human respiratory syncytial virus.
[3] Every infectious agent is different, but in general, slow viruses:[4] Additionally, the immune system seems to plays a limited role, or no role, in protection from many of these slow viruses.
This may be due to the slow replication rates some of these agents exhibit,[5] preexisting immunosuppression (as in the cases of JC virus and BK virus),[6] or, in the case of prions, the identity of the agent involved.
[7] Slow viruses cause a variety of diseases, including cancer.