The human body in the cold after the immunity may be how long?

The human body in the cold after the immunity may be how long?
Usually the body's cold caused by the influenza virus, the virus enters the human body, the body's immune system will make the appropriate response to resistance, this resistance is the immune response. After a cold immunity, the general could be maintained for about a month time, influenza may be the maintenance of 8 ~ 12 months. Although the post-cold machine experience have immunity, but can cause flu-type virus in many species, often in a cure for HIV infection, shortly after another occurred infection. Therefore, a person may be repeated in a short time the phenomenon of cold.