T-Cell Responses to COVID-19 Vaccines and Breakthrough Infection in People Living with HIV Receiving Antiretroviral Therapy

SIV/SARS-CoV-2 co-infection in rhesus macaques impacts viral shedding, host immunity, the microbiome, and viral evolution

People living with HIV (PLWH) have an increased risk of severe COVID-19, including prolonged viral shedding and emergence of mutations. To investigate the simian immunodeficiency virus (SIV) macaque model for HIV/SARS-CoV-2 co-infection, seven SIV+ rhesus macaques were co-infected with SARS-CoV-2. COVID-19 in all macaques was mild. SARS-CoV-2 replication persisted in the upper, but not the lower respiratory tract for 14 days post-infection. Animals showed impaired generation of anti-SARS-CoV-2 antibodies and T-cells. Animals also displayed transient changes in microbial communities in the upper airway and gastrointestinal tract. Evidence of SARS-CoV-2 evolution was observed in the upper respiratory tract. This study demonstrates that SIV/SARS-CoV-2 co-infection in rhesus macaques recapitulates aspects of COVID-19 in PLWH. We show that SIV impairs anti-SARS-CoV-2 immunity, potentially leading to prolonged viral shedding, altered pathogenesis, and viral evolution. This highlights the importance of HIV status in COVID-19 and supports the use of this model for HIV/SARS-CoV-2 co-infection.

Neutralizing Activity and T-Cell Responses Against Wild Type SARS-CoV-2 Virus and Omicron BA.5 Variant After Ancestral SARS-CoV-2 Vaccine Booster Dose in PLWH Receiving ART Based on CD4 T-Cell Count

BACKGROUND

We evaluated severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2)-specific humoral and cellular responses for up to 6 months after the 3rd dose of ancestral coronavirus disease 2019 (COVID-19) vaccination in people living with HIV (PLWH) and healthy controls (HCs) who were not infected with COVID-19.

METHODS

Anti-spike receptor-binding domain IgG (anti-RBD IgG) concentrations using chemiluminescence immunoassay and neutralizing antibodies using focus reduction neutralization test (FRNT) were assessed at 1 week after each dose of vaccination, and 3 and 6 months after the 3rd dose in 62 PLWH and 25 HCs. T-cell responses using intracellular cytokine stain were evaluated at 1 week before, and 1 week and 6 months after the 3rd dose.

RESULTS

At 1 week after the 3rd dose, adequate anti-RBD IgG (> 300 binding antibody unit /mL) was elicited in all PLWH except for one patient with 36 CD4 T-cell count/mm³. The geometric mean titers of 50% FRNT against wild type (WT) and omicron BA.5 strains of SARS-CoV-2 in PLWH with CD4 T-cell count ≥ 500 cells/mm³ (high CD4 recovery, HCDR) were comparable to HC, but they were significantly decreased in PLWH with CD4 T-cell count < 500/mm³ (low CD4 recovery, LCDR). After adjusting for age, gender, viral suppression, and number of preexisting comorbidities, CD4 T-cell counts < 500/mm³ significantly predicted a poor magnitude of neutralizing antibodies against WT, omicron BA.5, and XBB 1.5 strains among PLWH. Multivariable linear regression adjusting for age and gender revealed that LCDR was associated with reduced neutralizing activity (P = 0.017) and interferon-γ-producing T-cell responses (P = 0.049 for CD T-cell; P = 0.014 for CD8 T-cell) against WT, and strongly associated with more decreased cross-neutralization against omicron BA.5 strains (P < 0.001).

CONCLUSION

HCDR demonstrated robust humoral and cell-mediated immune responses after a booster dose of ancestral SARS-CoV-2 vaccine, whereas LCDR showed diminished immune responses against WT virus and more impaired cross-neutralization against omicron BA.5 strain.

COVID-19 Vaccination and Transient Increase in CD4/CD8 Cell Counts in People with HIV: Evidence from China

Objectives: Accumulating evidence has confirmed the efficacy and safety of COVID-19 vaccines against SARS-CoV-2 infection. However, the effect of COVID-19 vaccination on immuno-virological parameters in people with HIV (PWH) is uncertain. Methods: A total of 372 PWH treated at Beijing Ditan Hospital were included. Unvaccinated PWH were matched 1:3 with vaccinated PWH using a propensity score matching algorithm. Differences in immuno-virological markers between the matched groups were analyzed. The Wilcoxon signed rank test was used to test for changes in CD4 and CD8 counts and HIV viral load over two months around vaccination. In addition, we investigated the long-term changes in HIV-related markers in different vaccination dose groups and in the entire vaccinated population. Results: Vaccinated PWH had a higher CD4/CD8 ratio (0.64 (0.49, 0.78) vs. 0.80 (0.56, 1.03), p = 0.037) than unvaccinated PWH within a two-month window after the third dose. There were 337 PWH who received COVID-19 vaccination, and 73.9% (n = 249) received three doses of vaccine. We observed a transient increase in CD4 count and CD4/CD8 ratio within a two-month window after vaccination, especially after the second dose (CD4 count: 583.5 (428.5, 706.8) vs. 618.0 (452.0, 744.0), p = 0.018; CD4/CD8 ratio: 0.70 (0.50, 0.91) vs. 0.71 (0.53, 0.96), p < 0.001)) and the third dose (CD4 count: 575.5 (435.5, 717.0) vs. 577.5 (440.8, 754.8), p = 0.001; CD4/CD8 ratio: 0.70 (0.52, 0.93) vs. 0.79 (0.53, 1.00), p < 0.001)). Recent CD4 counts and CD4/CD8 ratios were lower than after COVID-19 but remained higher than before COVID-19 in vaccinated PWH. In addition, COVID-19 vaccination had no negative effect on HIV viral load. Conclusions: A transient increase in CD4 count and CD4/CD8 ratio was observed after COVID-19 vaccination. However, the enhanced cellular immune response induced by vaccination may diminish over time and return to normal levels. There is no adverse effect of vaccination on HIV viral load.