The humoral immune response against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variants of concern elicited by vaccination was evaluated in COVID‐19 recovered individuals (Rec) separated 1–3 months (Rec2m) or 4–12 months (Rec9m) postinfection and compared to the response in naïve participants. Antibody‐mediated immune responses were assessed in 66 participants by three commercial immunoassays and a SARS‐CoV‐2 lentiviral‐based pseudovirus neutralization assay. Immunoglobulin (Ig) levels against SARS‐CoV‐2 spike were lower in naïve participants after two doses than in Rec after a single dose (p < 0.05). After two doses in Rec, levels of total Ig to receptor‐binding domain were significantly increased in Rec9m compared to Rec2m (p < 0.001). The neutralizing potency observed in Rec9m was consistently higher than in Rec2m against variants of concern (VOCs) Alpha, Beta, Delta, and BA.1 sublineage of Omicron with 2.2–2.8‐fold increases. Increasing the interval between SARS‐CoV‐2 infection and the vaccination with messenger RNA‐based vaccines to more than 3 months generates a more efficient heterologous humoral immune response against VOCs by allowing enough time to mount a strong recall memory B cell response.

The presence of neutralizing antibodies (NAbs) is a major correlate of protection for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. Thus, different in vitro pseudoviruses‐based assays have been described to detect NAbs against SARS‐CoV‐2. However, the determination of NAbs against SARS‐CoV‐2 in people living with HIV (PLWH) through HIV‐based pseudoparticles could be influenced by cross‐neutralization activity or treatment, impeding accurate titration of NAbs. Two assays were compared using replication‐defective HIV or VSV‐based particles pseudotyped with SARS‐CoV‐2 spike to measure NAbs in COVID‐19‐recovered and COVID‐19‐naïve PLWH. The assay based on HIV‐pseudoparticles displayed neutralization activity in all COVID‐19‐recovered PLWH with a median neutralizing titer 50 (NT50) of 1417.0 (interquartile range [IQR]: 450.3−3284.0), but also in 67% of COVID‐19‐naïve PLWH (NT50: 631.5, IQR: 16.0−1535.0). Regarding VSV‐pseudoparticles system, no neutralization was observed in COVID‐19‐naïve PLWH as expected, whereas in comparison with HIV‐pseudoparticles assay lower neutralization titers were measured in 75% COVID‐19‐recovered PLWH (NT50: 100.5; IQR: 20.5−1353.0). Treatment with integrase inhibitors was associated with inaccurate increase in neutralization titers when HIV‐based pseudoparticles were used. IgG purification and consequent elimination of drugs from samples avoided the interference with retroviral cycle and corrected the lack of specificity observed in HIV‐pseudotyped assay. This study shows methodological alternatives based on pseudoviruses systems to determine specific SARS‐CoV‐2 neutralization titers in PLWH.

Maraviroc (MVC) is an antiretroviral drug capable of binding to CCR5 receptors and block HIV entry into target cells. Moreover, MVC can activate NF-kB pathway and induce viral transcription in HIV-infected cells, being proposed as a latency reversal agent (LRA) in HIV cure strategies. However, the evaluation of immunological and metabolic parameters induced by MVC concentrations capable of inducing HIV transcription have not been explored in depth. We cultured isolated CD4 T cells in the absence or presence of MVC, and evaluated the frequency of CD4 T cell subpopulations and activation markers levels by flow cytometry, and the oxidative and glycolytic metabolic rates of CD4 T cells using a Seahorse Analyzer. Our results indicate that a high concentration of MVC did not increase the levels of activation markers, as well as glycolytic or oxidative metabolic rates in CD4 T cells. Furthermore, MVC did not induce significant changes in the frequency and activation levels of memory cell subpopulations. Our data support a safety profile of MVC as a promising LRA candidate since it does not induce alterations of the immunological and metabolic parameters that could affect the functionality of these immune cells.

The elimination of the latent viral reservoir remains the main barrier in the quest for a cure for people with HIV (PWH). The administration of latency reversal agents (LRA) at antiretroviral treatment (ART) initiation could improve the effectiveness of strategies aimed at HIV remission. This study assessed the impact of maraviroc (MVC), an antiretroviral drug with HIV latency reversal properties, on the viral reservoir size when it is administered at ART initiation. We conducted a longitudinal observational study in PWH initiating ART with a regimen including (MVC-initiation, n = 12) or not including MVC (non-MVC-initiation, n = 22), or switching to an MVC-containing regimen after achieving an undetectable viral load (VL) (MVC-switch, n = 9). The HIV reservoir size was determined via Alu-LTR and Intact Proviral DNA Assay (IPDA) methods, and cell-associated HIV-RNA (ca-HIV-RNA) by nested-qPCR. Comparative analyses employed mixed multivariate linear models. After a median of 90 weeks, the MVC-initiation group showed a greater reduction in integrated and IPDA-total (7.1- and 4.0-fold, respectively), but not IPDA-intact, HIV-DNA reservoir compared to the non-MVC-initiation group. The reductions in integrated, IPDA-total, and IPDA-intact HIV-DNA levels in the MVC-initiation group were also greater compared to the MVC-switch group (from 5.4 to 13.8-fold). Moreover, no significant differences in the HIV transcriptional activity, assessed by ca-HIV-RNA levels or HIV-RNA/HIV-DNA ratios, were observed between the MVC-initiation and non-MVC-initiation groups. In conclusion, starting ART with a drug with HIV latency reversing activity at detectable VL phase may contribute to a greater reduction in the HIV-DNA reservoir. These findings could inform the design of future trials targeting HIV remission via a “kick and kill” strategy.

The dynamics of the HIV reservoir during antiretroviral therapy (ART) exhibit variability, with a pronounced decline during the initial years of treatment. However, the identification of biomarkers and host factors associated with the decay of the different forms of HIV proviruses remains to be fully elucidated. We conducted a longitudinal study on people with HIV provided by the Spanish National HIV cohort. We assessed the HIV-DNA levels by Intact Proviral DNA Assay, and inflammatory markers using the Proximity Extension Assay, before and after ART initiation. A multivariate linear regression model was employed to identify potential predictive markers. Our results highlight the identification of novel inflammatory markers, such as ADA, DNER, CDCP1, SCF, among others, that varied significantly over ART initiation. In addition, we observed several markers associated with intact HIV-DNA before ART initiation (CD8A, CX3CL1, and ST1A1) or during undetectable viral load post-ART (IL-10). Moreover, up to five markers were able to predict the intact HIV reservoir decay over ART. The strongest predictor was Stem Cell Factor (SCF), where higher baseline levels of this marker were associated with a greater decline in the intact HIV reservoir. In conclusion, we have identified inflammatory markers associated with the size and dynamics of the HIV-DNA reservoir. These findings provide new insights that could contribute to the development of multi-targeted intervention strategies aimed at modulating or monitoring the HIV reservoir size.