The purpose of this study is to compare the immunogenicity and safety of recombinant zoster vaccine according to CD4+ T-cell count and age in people living with HIV, and to provide evidence to guide immunization of people living with HIV.

• HIV-infected individuals willing to receive recombinant zoster vaccine will be recruited at three study hospitals.
• Participants are divided into two groups based on HIV status and CD4+ T cell count (HIV #1: CD4+ T cell count <300 cells/µL, HIV #2: CD4+ T cell count≥300 cells/µL, non-HIV).
• Target numbers are 50 for each group.
• Give 2 intramuscular doses of recombinant zoster vaccine 2 months apart.
• Contact by phone on days 3 and 7 after each dose to assess for adverse events.
• Evaluate immunogenicity at 1 month and 13 months after the second dose and safety.
• An interim analysis is planned after the first approximately 30 participants of HIV group and 10 participants of non-HIV group complete a visit 13 months after 2nd dose.
• Evaluation for the safety is planned after the first approximately 10 participants of the HIV #2 arm complete a visit 13 months after 2nd dose.

Inclusion Criteria (for HIV #1, HIV #2) :

• 19 years old or older, HIV-1 infected person who have voluntarily agreed to participate in the study.
• Have been taking antiviral medications stably for at least one month at the time of screening.
• Have a CD4+ T-cell count measured before enrollment.
• Do not have AIDS-defining diseases (excluding oral thrush) or acute/uncontrolled opportunistic infection at the time of enrollment.
• Do not have uncontrolled chronic medical conditions other than HIV infection.

Inclusion Criteria (for non-HIV) :

• 50 years old or older who have voluntarily agreed to participate in the study.
• Do not have uncontrolled chronic medical conditions

Exclusion Criteria:

• Have received any type of zoster vaccine within 1 year.
• Have been diagnosed with chickenpox or shingles within 12 months.
• Have a history of severe allergy to any of the components of Shingrix vaccine.
• Have a acute medical condition at the time of screening.
• Unable to be evaluated for adverse events via telephone contact after vaccination.
• Pregnant (including those planning to become pregnant) or lactating women.
• Those who have received chemotherapy or radiotherapy within 6 months prior to the first vaccine dose.
• Chronic administration of immunosuppressive or other immune-modifying drugs within 6 months prior to ther first vaccine dose.
• Administration of immunoglobulins, and/or any blood products within 3 months preceding the first dose of study vaccine
• Have a medical condition that makes receiving an intramuscular injection medically contraindicated.
• Have a disease or condition that may affect the immunogenicity or safety of the vaccine.
• Receiving any other vaccine within 14 days prior to and 14 days after receiving the study vaccine.
• Participate in a clinical trial that involves other investigational product or device during the course of the study.
• Any other person who, in the opinion of the investigator, is unsuitable for immune response assessment.

We are not planning to share IPDs publically, but de-identified individual participant data for all outcome measures could be shared with other researchers under their request.