Humoral immune response to two doses of COVID-19 mRNA-based vaccines in people living with HIV: A systematic review and meta-analysis.

People living with HIV (PLWH) are susceptible to severe COVID-19 infection and hence this fragile population has prioritised vaccination. This systematic review and meta-analysis aimed to assess the humoral immune response after receiving two doses schedule of COVID-19 mRNA vaccinations in this high-risk population. A systematic electronic search on the PubMed database and manual searches were performed for relevant articles until 30 Sep 2022. Two outcomes of interest were seroconversion rates and anti-spike receptor binding domain (anti-S-RBD) antibody titres at the median time of 14-35 days following two-dose vaccination among PLWH. Nineteen cohorts and one cross-sectional study were eligible for inclusion in this study. The pooled estimate of seroconversion rate after receiving two doses of mRNA vaccination schedule were 98.4% and 75.2% among PLWH with CD4>500 cells/mm and CD4<200 cells/mm , respectively. Compared with controls, PLWH with CD4>500 cells/mm had a 51% likelihood of having positive anti-Spike-RBD immunoglobulin G (IgG) (OR: 0.509, 95% CI: 0.228, 1.133, p = 0.098) post-vaccination and this value was only 1.4% (OR: 0.014, 95% CI: 0.002, 0.078, p = 0.000) for PLWH with CD4<200 cells/mm . There was no significant difference in titres of antibodies on 14-35 days post-vaccination between PLWH with CD4>500 cells/mm and healthy controls (p = 0.06). The pooled median of anti-S-RBD IgG values were 1461.93 binding antibody units (BAU)/ml and 457.41 BAU/ml in PLWH with CD4>500 cells/mm and CD4<200 cells/mm , respectively. According to these findings, vaccination with both Pfizer-BioNTech and Moderna vaccines induced a robust humoral response in ART-treated HIV patients with preserved CD cell count. A diminished humoral immune response to vaccination against COVID-19 in PLWH with unrestored CD4 count implied the need of specific vaccination schemes.