A vector is a carrier (mosquito, tick) that takes the disease from an infected individual to an uninfected individual. They do not have the disease themselves, they carry the infected agent such as blood. A reservoir is anything (person, animal, arthropod, plant, soil or substance) in which a disease lives and can multiply. The disease needs the reservoir in order to survive. A vector must be living but a reservoir can be a living or a non living thing such as soil or water. Vectors or carriers are not pathogenic but are simply transmitters.