Humoral and Cellular Immune Response Elicited by mRNA Vaccination Against SARS-CoV-2 in People Living with HIV (PLWH) Receiving Antiretroviral Therapy (ART) According with Current CD4 T-Lymphocyte Count

Abstract

Background: Data on SARS-CoV-2 vaccine immunogenicity in PLWH are currently limited. Aim of the study was to investigate immunogenicity according to current CD4 T-cell count and predictive role on immune response to vaccination in PLWH.Methods: PLWH attending a single-center SARS-CoV-2 vaccination program in Italy, were included in a prospective evaluation for immunogenicity after receiving BNT162b2 or mRNA-1273. PLWH were stratified according to current CD4 T-cell count (severe immunodeficiency, SID: 500/mm 3 ). RBD-binding IgG, SARS-CoV-2 neutralizing antibodies (nAbs) and cell-mediated (IFN-γ/IL-2) immune response were measured. As control group, not-matched HIV-negative healthcare workers (HCWs) were used.Findings: Participants were 166 PLWH (SID=32; MID=56; NID=78) on ART. After 1 month from the booster dose, detectable RBD-binding IgG in 86.7% of SID, in 100% of MID, in 98.7% of NID (SID vs NID, p=0.021) and nAbs (titre ≥1:10) in 70.0%, 88.2% and 93.1%, respectively (SID vs NID, p=0.002), were elicited. Compared to NID, magnitude of anti-RBD, nAbs and IFN-γ production was significantly lower in SID and comparable in MID. After adjusting for confounders, current CD4 T-cell Interpretation: Neutralizing and cell-mediated immune response against SARS-CoV-2 were elicited in most of PLWH receiving ART, albeit significantly poorer in those with current CD4 T-cell 500/mm 3 and HIV-negative controls. A marginal decreased immunogenicity than HCWs was also observed in PLWH with CD4 T-cell 200-500/mm 3 , whereas immune response elicited in PLWH with a CD4 T-cell >500/mm 3 was comparable to HIV-negative population.Funding: Italian Ministry of Health; European Commission, European Virus Archive – GLOBAL.Declaration of Interest: None to declare. Ethical Approval: The study was approved by the Scientific Committee of the Italian Drug Agency (AIFA) and by the Ethical Committee of the Lazzaro Spallanzani Institute, as National Review Board for COVID-19 pandemic in Italy (approval number 323/2021).