Importantly, a disease’s R 0 value only applies when everyone in a population is completely vulnerable to the disease. The disease will be transmitted between people, and there may be an outbreak or epidemic.
The disease will stay alive and stable, but there won’t be an outbreak or an epidemic. In this case, the disease will decline and eventually die out.
Three possibilities exist for the potential transmission or decline of a disease, depending on its R 0 value:
