Limited humoral and specific T-cell responses after SARS-CoV-2 vaccination in PLWH with poor immune reconstitution.

Background: We analyzed humoral and cellular immune responses induced by SARS-CoV-2 mRNA vaccines in people living with HIV-1 (PLWH) with  200 CD4+ T-cells.

Methods: Prospective cohort study including 58 PLWH with CD4+ T-cell counts 200 cells/mm3, 36 with CD4+ T-cell counts >500, and 33 HIV-1-negative controls. Antibodies against the SARS-CoV-2 Spike protein (anti-S IgG) and the receptor-binding domain (anti-RBD IgG) were quantified before and four weeks after the first and the second dose of BNT162b2 or mRNA-1273 (w8). Viral neutralization activity and T-cell responses were also determined.

Results: At w8, anti-S/anti-RBD IgG responses increased in all groups (P  0.0001). Median (IQR) S-IgG and RBD-IgG at w8 were 153.6 (26.4; 654.9) and 171.9 (61.8; 425.8) in the HIV  200 group compared to 245.6 (145; 824) and 555.8 (166.4; 1751) in the HIV > 500 group, and 274.7 (193.7; 680.4) and 281.6 (181; 831.8) BAU/mL in controls (P  0.05). Neutralizing capacity and specific T-cell immune responses were absent or reduced in 33% of the HIV  200 group, compared with 3.7% in the HIV > 500 (P = 0.0003).

Conclusion: At w8, anti-S/anti-RBD IgG responses increased in all groups (P  0.0001). Median (IQR) S-IgG and RBD-IgG at w8 were 153.6 (26.4; 654.9) and 171.9 (61.8; 425.8) in the HIV  200 group compared to 245.6 (145; 824) and 555.8 (166.4; 1751) in the HIV > 500 group, and 274.7 (193.7; 680.4) and 281.6 (181; 831.8) BAU/mL in controls (P  0.05). Neutralizing capacity and specific T-cell immune responses were absent or reduced in 33% of the HIV  200 group, compared with 3.7% in the HIV > 500 (P = 0.0003).