Abstract Background and Aims No data exists on humoral or cellular responses to mRNA vaccines in kidney transplant recipients (KTR) with HIV. We compared these responses in HIV-positive and negative KTR, as well as in people living with HIV (PLWH) without kidney transplantation. Method In a cross-sectional study of 33 patients receiving two (n=13) or three (n=20) doses of mRNA SARS-CoV-2 vaccination, we evaluated the humoral response to mRNA SARS-CoV-2 vaccination using a Luminex platform for IgG and IgM, and assessed cellular response with specific T cell response with S- and N- protein by ELISpot. We used logistic regression models to assess associated factors. Results The study comprised 11 HIV-negative KTRs (HIV-KTR+), 11 HIV-positive KTRs (HIV+KTR+), and 11 PLWH without kidney transplantation (HIV+KTR−). PLWH had suppressed viral load on ART. Seroconversion rates after two or three vaccine doses were 72.7% among KTRs, with no significant difference between HIV-KTR+ (81.8%) and HIV+KTR+ (63.6%) (P=0.338). In HIV+KTR−, seroconversion was 100%, higher than HIV+KTR+ (P=0.027). Cellular response against protein S occurred in 63.6% cases, irrespective of HIV or transplantation status or number of doses. Protein N reactivity was observed in 27.3% KTRs (HIV-KTR+ and HIV+KTR+), versus 9.1% HIV+KTR− (P=0.378). Higher age negatively influenced cellular response in PLWH (OR 0.77, 95% CI 0.60-0.99). Conclusion Although cellular immune response was similar across all groups, we found a reduced humoral response in HIV+KTR+. In PLWH, higher age reduced cellular response. These findings contribute to our understanding of vaccine response in immunosuppressed populations and provide valuable insights for optimizing vaccination strategies.