Roser Navarro-Soler, Megan J Heise, Thomas Dalhuisen, Halle Grebe, Dylan Ryder, Antonio E Rodriguez, Melissa Buitrago, Rebecca Hoh, Alessandro Sette, Peter W Hunt, Michiko Shimoda, Timothy J Henrich, Kara Lynch, Raul Andino-Pavlosky, Jeffrey N Martin, Steven G Deeks, Rachel L Rutishauser, Matthew A Spinelli, Michael J Peluso
CD4+ T cell count influences antibody persistence, while the CD4/CD8 ratio affects initial antibody magnitude and Tfh cell frequencies, highlighting complementary roles in shaping vaccine responses in PLWH.
OBJECTIVE: To evaluate the durability of SARS-CoV-2-specific humoral and cellular immune responses after booster vaccination in people living with HIV (PLWH) in a prospective longitudinal cohort study.
METHODS: We analyzed 46 PLWH with no prior history of SARS-CoV-2 infection who received a booster dose. Anti-receptor-binding domain (RBD) IgG concentrations, neutralization titers, and T cell responses were measured over time. The associations between CD4+ T cell count and CD4/CD8 ratio with antibody dynamics were assessed, adjusting for age, sex, and vaccine type.
RESULTS: Anti-RBD IgG and neutralization titers declined significantly over time. Participants with CD4+ T cell counts <500 cells/μL exhibited a 3-fold faster decline in anti-RBD IgG compared to those with ≥500 cells/μL. Neutralization capacity declined similarly across both groups, suggesting that CD4+ T cell count primarily influences antibody quantity rather than functional quality. A lower CD4/CD8 ratio was independently associated with reduced baseline IgG concentrations but did not influence the rate of antibody decay. In a subset of 30 participants, a lower CD4/CD8 ratio was also associated with altered follicular helper (Tfh) CD4+ T cell frequencies and faster decline of Spike-specific Tfh over time.
CONCLUSIONS: CD4+ T cell count influences antibody persistence, while the CD4/CD8 ratio affects initial antibody magnitude and Tfh cell frequencies, highlighting complementary roles in shaping vaccine responses in PLWH.