TOPLINE

A recombinant zoster vaccine induced robust antibody responses in people living with HIV (PLWH) regardless of their CD4 count, with nearly all participants achieving humoral vaccine response after two doses. However, cell-mediated immunity was weaker in PLWH than in those without HIV.

METHODOLOGY

• Researchers conducted a nonrandomized clinical trial in South Korea (June 2023 to November 2024) to assess the immunogenicity and safety of recombinant zoster vaccine in PLWH across low and high CD4 counts and in participants without HIV.
• They included 60 virologically suppressed PLWH on antiretroviral therapy and 10 participants without HIV; all participants were men, with a median age ranging from 52.0 to 58.5 years. PLWH were classified into low CD4 (< 300 cells/µL; n = 30) and high CD4 (≥ 300 cells/µL; n = 30) groups.
• All participants received two 0.5-mL intramuscular doses of recombinant zoster vaccine at weeks 0 and 8.
• The primary outcome was the humoral vaccine response rate: at least a fourfold rise in anti-glycoprotein E antibody titers from baseline, measured 4 weeks after the second dose in participants who were initially seropositive.
• Secondary outcomes included the cell-mediated vaccine response rate — at least a twofold rise in anti-glycoprotein E-specific CD4²⁺ T cells from baseline, also measured 4 weeks after the second dose — and reactogenicity, assessed on days 3 and 7 after vaccination.

TAKEAWAY

• At 1 month after the second dose, the humoral vaccine response rate was 100% in all groups, with no between-group differences with respect to the fold increase in anti-glycoprotein E titers from baseline.
• The cell-mediated vaccine response rate at 1 month after the second dose differed significantly across the groups: 33.3% among PLWH in the low CD4 group, 50.0% among PLWH in the high CD4 group, and 80.0% among participants without HIV (P = .041).
• The most common adverse event was pain at the injection site within 7 days of vaccination; no adverse events of grade 3 or higher were reported.
• During the 1-month follow-up after the second dose, no unsolicited serious adverse events or cases of herpes zoster were reported in any group.

IN PRACTICE

"[The study] findings support the current guidelines recommending administration of RZV [recombinant zoster vaccine] to PLWH, regardless of the CD4 count," the authors wrote.

SOURCE

The study was led by Min-Kyung Kim, National Medical Center, and Hyeon Jae Jo, Seoul National University College of Medicine, both in Seoul, South Korea. It was published online on September 08, 2026, in the International Journal of Infectious Diseases.

LIMITATIONS

The study had a small sample size in each group. The researchers could not use the vaccine manufacturer-provided assay kit or the glycoprotein E-specific stimulation antigens used in previous zoster vaccine-related clinical trials. Finally, all participants were men.

DISCLOSURES

The study was supported by Seoul National University Hospital Research Fund, the Creative-Pioneering Researchers Program through Seoul National University, and the National Medical Center, Republic of Korea. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.