Below is an instruction from Human. Write a response.
    ### Instruction:
    Who is at risk for Shingles? ?
    ### Response:
    The leading risk factor for shingles is a history of having had chickenpox. One out of every five people who have had chickenpox is likely to get shingles. Another risk factor is aging. As we age, our natural immunity gradually loses its ability to protect against infection.
    