The CD4+ T cell count was shown to inversely correlate with  enhanced morbidity and mortality for COVID-19 in PLWHIV 37. We observed that the anti-SARS-CoV-2 IgG response of subjects in the Low CD4+ T cell (≤ 350/mmc) subgroup was generally low, in line to what reported previously14, possibly reflecting a reduced ability to develop a strong antibody response after the boost. Here, CD4 is linked to COVID-19.