It is generally true that after having chickenpox, the vast majority of people develop lifelong immunity and will not get it again. The virus remains dormant in the body and can reactivate later as shingles, but a full-blown second case of chickenpox is uncommon. However, it is not impossible. Second cases, while rare, are most likely to occur in individuals with compromised immune systems, such as those undergoing chemotherapy, taking high-dose steroids, or living with HIV. Additionally, someone who had an extremely mild or "breakthrough" case the first time (with very few spots) may have mounted a less robust immune response, making them slightly more susceptible to a reinfection, though it would likely be mild again.