Can a person get chickenpox again after having had it once?

Generally, people who have had chickenpox usually do not get infected again. However, under certain circumstances, reinfection may still occur.

Chickenpox is an acute infectious disease caused by the initial infection of the varicella-zoster virus. After recovery from chickenpox, the human body produces specific antibodies against the virus, which can help defend against subsequent infections. Usually, individuals who have had chickenpox will not contract it again.

Individuals suffering from certain diseases such as HIV/AIDS, leukemia, lymphoma, or those undergoing immunosuppressive therapy may experience decreased immunity, thereby increasing the risk of reinfection with chickenpox. Some elderly individuals may also have insufficient production of protective antibodies due to weakened immunity, leading to possible reinfection with chickenpox.

Close contact with a person who has chickenpox, particularly from one to two days before the rash appears until all the skin lesions have completely crusted over, may result in infection. However, reinfection in such cases is relatively rare because the body has already developed antibodies against the varicella virus. Due to individual variations among viral subtypes of chickenpox currently circulating, a small number of people may become reinfected with a different subtype of the varicella virus and develop chickenpox again. Nevertheless, this scenario is also relatively uncommon.

After the initial infection with chickenpox, the body typically develops long-lasting immunity, making reinfection unlikely. However, the possibility of reinfection cannot be completely ruled out, particularly for individuals with compromised immune function. Such individuals should take enhanced preventive measures, avoid contact with people who have chickenpox, and consider varicella vaccination when necessary to strengthen immunity and reduce the risk of reinfection.