It is very rare for a person to get chickenpox twice. Once a person has been infected with the varicella-zoster virus (VZV), the virus remains dormant in the body, usually in the nerve roots that supply the skin. After the initial infection, the person develops immunity to the virus, which protects them from getting chickenpox again.
However, in some rare cases, a person may get a mild case of chickenpox again, usually because of a weakened immune system due to certain medical conditions or treatments.
It is also worth noting that after the initial infection, the virus can reactivate later in life, causing a condition known as shingles (Herpes Zoster), which is a painful rash that develops on one side of the face or body. This occurs because the virus reactivates in the nerve roots and travels along a nerve to the skin. Anyone who has had chickenpox can develop shingles, but it is most common in older adults and people with weakened immune systems.