Upregulation of PTPRC and Interferon Response Pathways in HIV-1 Seroconverters Prior to Infection.

Human immunodeficiency virus 1 (HIV-1) exposed seronegative (HESN) individuals may have unique characteristics that alter susceptibility to HIV-1 infection. However, identifying truly exposed HESN is challenging. We utilized stored data and biospecimens from HIV-1 serodifferent couple cohorts, in which couples' HIV-1 exposures were quantified based on unprotected sex frequency and viral load of the partner with HIV-1. We compared peripheral blood gene expression between 15 HESN and 18 seroconverters prior to infection. We found PTPRC (encoding CD45 antigen) and interferon-response pathways had significantly higher expression among individuals who went on to become seropositive and thus may be a signature for increased acquisition risk.

Transient Increase in Herpes Simplex Virus Type 2 (HSV-2)-Associated Genital Ulcers Following Initiation of Antiretroviral Therapy in HIV/HSV-2-Coinfected Individuals.

BACKGROUND: Immune reconstitution inflammatory syndrome (IRIS) in human immunodeficiency virus (HIV)-infected persons beginning antiretroviral therapy (ART) has been incompletely characterized for herpes simplex virus type 2 (HSV-2). METHODS: We evaluated genital ulcer disease (GUD) and HSV-2-associated GUD at quarterly visits or when spontaneously reported at monthly visits in 3381 HIV/HSV-2-coinfected individuals in a placebo-controlled trial of suppressive acyclovir therapy to prevent HIV transmission, 349 of whom initiated ART during the study. Incidence was calculated for months before and after ART initiation, and incidence rate ratios (IRRs) were calculated. RESULTS: GUD incidence increased from 15.0 episodes per 100 person-years before ART to 26.9 episodes per 100 person-years in the first full quarter after ART initiation (IRR, 1.83;P= .03), and the incidence of HSV-2-associated GUD increased from 8.1 to 19.0 episodes per 100 person-years (IRR, 2.20;P= .02). Subsequently, the incidence of GUD was similar to that before ART, although the numbers were small. Persons receiving suppressive acyclovir had fewer GUD episodes, but the IRR after beginning ART was similar in the acyclovir and placebo groups. CONCLUSIONS: Initiation of ART in HIV/HSV-2-coinfected persons is associated with a transient increase in GUD and HSV-2 GUD. Acyclovir reduces the incidence of GUD but does not prevent an increase in GUD incidence during the first quarter following initiation of ART.

Sexual communication self-efficacy, hegemonic masculine norms and condom use among heterosexual couples in South Africa.

Hegemonic masculine norms (HMN), which promote sexual risk-taking among males and the subordination of women, are believed to play a key role in the HIV epidemic among heterosexual couples in South Africa (SA). Sexual communication self-efficacy (SCSE) (i.e., a couple's confidence in their ability to communicate about HIV prevention) may be a key leverage point for increasing HIV prevention behaviors among this population. We interviewed 163 sexually active heterosexual couples in Soweto, SA to investigate the association between SCSE, HMN, and consistent condom use. We collected information on demographics, relationship dynamics, and sexual activity. We utilized the SCSE scale to measure couples' SCSE, and a subscale of the Gender Equitable Men scale to measure HMN among males. We performed bivariate and multivariable analyses to determine the association of consistent condom use with couples' SCSE as well as the male partner's endorsement of HMN. We found that couples with higher SCSE have greater odds of consistent condom use (adjusted odds ratio [AOR] = 1.30, 95% CI: 1.15-1.47). Furthermore, male endorsement of HMN was found to be negatively associated with consistent condom use among couples (AOR = 0.47, 95% CI: 0.24-0.89). Joint HIV serostatus was not significantly associated with the outcome. Future interventions that equip heterosexual couples with sexual communication skills, while simultaneously promoting more gender equitable norms, may increase consistent condom use and thereby reduce the transmission of HIV among this at-risk population.

Plasma cytokine levels and risk of HIV type 1 (HIV-1) transmission and acquisition: a nested case-control study among HIV-1-serodiscordant couples.

BACKGROUND: A heightened proinflammatory state has been hypothesized to enhance human immunodeficiency virus type 1 (HIV-1) transmission - both susceptibility of HIV-1-exposed persons and infectiousness of HIV-1-infected persons. METHODS: Using prospective data from heterosexual African couples with HIV-1 serodiscordance, we conducted a nested case-control analysis to assess the relationship between cytokine concentrations and the risk of HIV-1 acquisition. Case couples (n = 120) were initially serodiscordant couples in which HIV-1 was transmitted to the seronegative partner during the study; control couples (n = 321) were serodiscordant couples in which HIV-1 was not transmitted to the seronegative partner. Differences in a panel of 30 cytokines were measured using plasma specimens from both HIV-1-susceptible and HIV-1-infected partners. Plasma was collected before seroconversion for cases. RESULTS: For both HIV-1-infected and HIV-1-susceptible partners, cases and controls had significantly different mean responses in cytokine panels (P < .001, by the Hotelling T(2) test), suggesting a broadly different pattern of immune activation for couples in which HIV-1 was transmitted, compared with couples without transmission. Individually, log10 mean concentrations of interleukin 10 (IL-10) and CXCL10 were significantly higher for both HIV-1-susceptible and HIV-1-infected case partners, compared with HIV-1-susceptible and HIV-1-infected control partners (P < .01 for all comparisons). In multivariate analysis, HIV-1 transmission was significantly associated with elevated CXCL10 concentrations in HIV-1-susceptible partners (P = .001) and with elevated IL-10 concentrations in HIV-1-infected partners (P = .02). CONCLUSIONS: Immune activation, as measured by levels of cytokine markers, particularly elevated levels of IL-10 and CXCL1, are associated with increased HIV-1 susceptibility and infectiousness.

Toll-like receptor polymorphism associations with HIV-1 outcomes among sub-Saharan Africans.

OBJECTIVE: We evaluated Toll-like receptors (TLRs) single nucleotide polymorphisms (SNPs) for associations with HIV-1 acquisition, set-point and disease progression in African couples. METHODS: Seven candidate and 116 haplotype-tagging SNPs (tagSNPs) were genotyped in 504 HIV-1 infected cases, and 343 seronegative controls. RESULTS: TLR9 1635A/G was associated with reduced HIV-1 acquisition among HIV-seronegative controls with high but not low HIV-1 exposure (odds ratio [OR] = 0.7; P = .03 and OR = 0.9, P = .5, respectively). TLR7 rs179012 and TLR2 597C/T reduced set-point; the latter modified by time since HIV-1 acquisition. TLR8 1A/G reduced disease progression. CONCLUSIONS: TLR SNPs impact HIV-1 outcomes with epidemiologic factors modifying these relationships.

Prevention of HIV-1 infection with early antiretroviral therapy.

BACKGROUND: Antiretroviral therapy that reduces viral replication could limit the transmission of human immunodeficiency virus type 1 (HIV-1) in serodiscordant couples. METHODS: In nine countries, we enrolled 1763 couples in which one partner was HIV-1-positive and the other was HIV-1-negative; 54% of the subjects were from Africa, and 50% of infected partners were men. HIV-1-infected subjects with CD4 counts between 350 and 550 cells per cubic millimeter were randomly assigned in a 1:1 ratio to receive antiretroviral therapy either immediately (early therapy) or after a decline in the CD4 count or the onset of HIV-1-related symptoms (delayed therapy). The primary prevention end point was linked HIV-1 transmission in HIV-1-negative partners. The primary clinical end point was the earliest occurrence of pulmonary tuberculosis, severe bacterial infection, a World Health Organization stage 4 event, or death. RESULTS: As of February 21, 2011, a total of 39 HIV-1 transmissions were observed (incidence rate, 1.2 per 100 person-years; 95% confidence interval [CI], 0.9 to 1.7); of these, 28 were virologically linked to the infected partner (incidence rate, 0.9 per 100 person-years, 95% CI, 0.6 to 1.3). Of the 28 linked transmissions, only 1 occurred in the early-therapy group (hazard ratio, 0.04; 95% CI, 0.01 to 0.27; P<0.001). Subjects receiving early therapy had fewer treatment end points (hazard ratio, 0.59; 95% CI, 0.40 to 0.88; P=0.01). CONCLUSIONS: The early initiation of antiretroviral therapy reduced rates of sexual transmission of HIV-1 and clinical events, indicating both personal and public health benefits from such therapy. (Funded by the National Institute of Allergy and Infectious Diseases and others; HPTN 052 ClinicalTrials.gov number, NCT00074581.).

Increased memory differentiation is associated with decreased polyfunctionality for HIV but not for cytomegalovirus-specific CD8+ T cells.

The generation of polyfunctional CD8(+) T cells, in response to vaccination or natural infection, has been associated with improved protective immunity. However, it is unclear whether the maintenance of polyfunctionality is related to particular cellular phenotypic characteristics. To determine whether the cytokine expression profile is linked to the memory differentiation stage, we analyzed the degree of polyfunctionality of HIV-specific CD8(+) T cells within different memory subpopulations in 20 antiretroviral therapy-naive HIV-1-infected individuals at ∼34 wk postinfection. These profiles were compared with CMV-specific CD8(+) T cell responses in HIV-uninfected control subjects and in individuals chronically infected with HIV. Our results showed that the polyfunctional abilities of HIV-specific CD8(+) T cells differed according to their memory phenotype. Early-differentiated cells (CD45RO(+)CD27(+)) exhibited a higher proportion of cells positive for three or four functions (p < 0.001), and a lower proportion of monofunctional cells (p < 0.001) compared with terminally differentiated (TD; CD45RO(-)CD27(-)) HIV-specific CD8(+) T cells. The majority of TD HIV-specific CD8(+) T cells were monofunctional (median 69% [interquartile range: 57-83]), producing predominantly CD107a or MIP1ß. Moreover, proportions of HIV-specific monofunctional CD8(+) T cells positively associated with proportions of TD HIV-specific CD8(+) T cells (p = 0.019, r = 0.54). In contrast, CMV-specific CD8(+) T cell polyfunctional capacities were similar across all memory subpopulations, with terminally and early-differentiated cells endowed with comparable polyfunctionality. Overall, these data show that the polyfunctional abilities of HIV-specific CD8(+) T cells are influenced by the stage of memory differentiation, which is not the case for CMV-specific responses.

Frequent genital HSV-2 shedding among women during labor in Soweto, South Africa.

BACKGROUND: Despite high herpes simplex virus type 2 (HSV-2) incidence and prevalence among women in Africa, we are unaware of published neonatal herpes reports. To assess neonatal HSV transmission potential in South Africa, we investigated the frequency of the strongest risk factors: HSV acquisition in late pregnancy and HSV shedding during labor. METHODS: Women admitted in early labor to a hospital in Soweto underwent HSV serologic testing and genital swab collection for HSV PCR. HSV-2 seronegative women were assessed for seroconversion 4-6 weeks after delivery. RESULTS: Of 390 women enrolled, 229 (58.7%) were HSV-2 seropositive. Genital HSV-2 was detected in 17.2% of HSV-2 seropositive women, including 26 of 115 HIV-positive and 13 of 110 HIV-negative women (22.6% versus 11.8%; RR, 1.91; 95% CI, 1.04-3.53; P = 0.038), but in none of 161 HSV-2 seronegative women. Among the 91 HSV-2 seronegative women followed after delivery, none seroconverted. CONCLUSIONS: HSV-2 reactivation is common among South African women during labor, especially those with HIV coinfection. To determine the epidemiology of neonatal herpes in South Africa and to investigate whether the lack of reported cases is due to alterations in immune control or HSV-2 virulence, studies evaluating acutely ill neonates for HSV and studies of maternal HSV-2 shedding patterns are needed.

Daily acyclovir to decrease herpes simplex virus type 2 (HSV-2) transmission from HSV-2/HIV-1 coinfected persons: a randomized controlled trial.

BACKGROUND: Daily suppressive therapy with valacyclovir reduces risk of sexual transmission of herpes simplex virus type 2 (HSV-2) in HSV-2-serodiscordant heterosexual couples by 48%. Whether suppressive therapy reduces HSV-2 transmission from persons coinfected with HSV-2 and human immunodeficiency virus type 1 (HIV-1) is unknown. METHODS: Within a randomized trial of daily acyclovir 400 mg twice daily in African HIV-1 serodiscordant couples, in which the HIV-1-infected partner was HSV-2 seropositive, we identified partnerships in which HIV-1-susceptible partners were HSV-2 seronegative to estimate the effect of acyclovir on risk of HSV-2 transmission. RESULTS: We randomly assigned 911 HSV-2/HIV-1-serodiscordant couples to daily receipt of acyclovir or placebo. We observed 68 HSV-2 seroconversions, 40 and 28 in acyclovir and placebo groups, respectively (HSV-2 incidence, 5.1 cases per 100 person-years; hazard ratio [HR], 1.35 [95% confidence interval, .83-2.20]; P = .22). Among HSV-2-susceptible women, vaginal drying practices (adjusted HR, 44.35; P = .004) and unprotected sex (adjusted HR, 9.91; P = .002) were significant risk factors for HSV-2 acquisition; having more children was protective (adjusted HR, 0.47 per additional child; P = .012). Among HSV-2-susceptible men, only age ≤30 years was associated with increased risk of HSV-2 acquisition (P = .016). CONCLUSIONS: Treatment of African HSV-2/HIV-1-infected persons with daily suppressive acyclovir did not decrease risk of HSV-2 transmission to susceptible partners. More-effective prevention strategies to reduce HSV-2 transmission from HIV-1-infected persons are needed.

Beta-variant recombinant booster vaccine elicits broad cross-reactive neutralization of SARS-CoV-2 including Omicron variants.

Background: SARS-CoV-2 Omicron lineage contains variants with multiple sequence mutations relative to the ancestral strain particularly in the viral spike gene. These mutations are associated inter alia with loss of neutralization sensitivity to sera generated by immunization with vaccines targeting ancestral strains or prior infection with circulating (non-Omicron) variants. Here we present a comparison of vaccine formulation elicited cross neutralization responses using two different assay readouts from a subpopulation of a Phase II/III clinical trial. Methods: Human sera from a Phase II/III trial (NCT04762680) was collected and evaluated for neutralizing responses to SARS-CoV-2 spike antigen protein vaccines formulated with AS03 adjuvant, following a primary series of two-doses of ancestral strain vaccine in individuals who were previously unvaccinated or as an ancestral or variant strain booster vaccine among individuals previously vaccinated with the mRNA BNT162b2 vaccine. Results: We report that a neutralizing response to Omicron BA.1 is induced by the two-dose primary series in 89% of SARS-CoV-2-seronegative individuals. A booster dose of each vaccine formulation raises neutralizing antibody titers that effectively neutralizes Omicron BA.1 and BA.4/5 variants. Responses are highest after the monovalent Beta variant booster and similar in magnitude to human convalescent plasma titers. Conclusion: The findings of this study suggest the possibility to generate greater breadth of cross-neutralization to more recently emerging viral variants through use of a diverged spike vaccine in the form of a Beta variant booster vaccine.

Identification and characterisation of vaginal lactobacilli from South African women.

BACKGROUND: Bacterial vaginosis (BV), which is highly prevalent in the African population, is one of the most common vaginal syndromes affecting women in their reproductive age placing them at increased risk for sexually transmitted diseases including infection by human immunodeficiency virus-1. The vaginal microbiota of a healthy woman is often dominated by the species belonging to the genus Lactobacillus namely L. crispatus, L. gasseri, L. jensenii and L. iners, which have been extensively studied in European populations, albeit less so in South African women. In this study, we have therefore identified the vaginal Lactobacillus species in a group of 40 African women from Soweto, a township on the outskirts of Johannesburg, South Africa. METHODS: Identification was done by cultivating the lactobacilli on Rogosa agar, de Man-Rogosa-Sharpe (MRS) and Blood agar plates with 5% horse blood followed by sequencing of the 16S ribosomal DNA. BV was diagnosed on the basis of Nugent scores. Since some of the previous studies have shown that the lack of vaginal hydrogen peroxide (H2O2) producing lactobacilli is associated with bacterial vaginosis, the Lactobacillus isolates were also characterised for their production of H2O2. RESULTS: Cultivable Lactobacillus species were identified in 19 out of 21 women without BV, in three out of five women with intermediate microbiota and in eight out of 14 women with BV. We observed that L. crispatus, L. iners, L. jensenii, L. gasseri and L. vaginalis were the predominant species. The presence of L. crispatus was associated with normal vaginal microbiota (P = 0.024). High level of H2O2 producing lactobacilli were more often isolated from women with normal microbiota than from the women with BV, although not to a statistically significant degree (P = 0.064). CONCLUSION: The vaginal Lactobacillus species isolated from the cohort of South African women are similar to those identified in European populations. In accordance with the other published studies, L. crispatus is related to a normal vaginal microbiota. Hydrogen peroxide production was not significantly associated to the BV status which could be attributed to the limited number of samples or to other antimicrobial factors that might be involved.

Determinants of per-coital-act HIV-1 infectivity among African HIV-1-serodiscordant couples.

BACKGROUND: Knowledge of factors that affect per-act infectivity of human immunodeficiency virus type 1 (HIV-1) is important for designing HIV-1 prevention interventions and for the mathematical modeling of the spread of HIV-1. METHODS: We analyzed data from a prospective study of African HIV-1-serodiscordant couples. We assessed transmissions for linkage within the study partnership, based on HIV-1 sequencing. The primary exposure measure was the HIV-1-seropositive partners' reports of number of sex acts and condom use with their study partner. RESULTS: Of 3297 couples experiencing 86 linked HIV-1 transmissions, the unadjusted per-act risks of unprotected male-to-female (MTF) and female-to-male (FTM) transmission were 0.0019 (95% confidence interval [CI], .0010-.0037) and 0.0010 (95% CI, .00060-.0017), respectively. After adjusting for plasma HIV-1 RNA of the HIV-1-infected partner and herpes simplex virus type 2 serostatus and age of the HIV-1-uninfected partner, we calculated the relative risk (RR) for MTF versus FTM transmission to be 1.03 (P = .93). Each log(10) increase in plasma HIV-1 RNA increased the per-act risk of transmission by 2.9-fold (95% CI, 2.2-3.8). Self-reported condom use reduced the per-act risk by 78% (RR = 0.22 [95% CI, .11-.42]). CONCLUSIONS: Modifiable risk factors for HIV-1 transmission were plasma HIV-1 RNA level and condom use, and, in HIV-1-uninfected partners, herpes simplex virus 2 infection, genital ulcers, Trichomonas vaginalis, vaginitis or cervicitis, and male circumcision.

Quantifying ongoing HIV-1 exposure in HIV-1-serodiscordant couples to identify individuals with potential host resistance to HIV-1.

BACKGROUND: Immunogenetic correlates of resistance to HIV-1 in HIV-1-exposed seronegative (HESN) individuals with consistently high exposure may inform HIV-1 prevention strategies. We developed a novel approach for quantifying HIV-1 exposure to identify individuals remaining HIV-1 uninfected despite persistent high exposure. METHODS: We used longitudinal predictors of HIV-1 transmission in HIV-1 serodiscordant couples to score HIV-1 exposure and define HESN clusters with persistently high, low, and decreasing risk trajectories. The model was validated in an independent cohort of serodiscordant couples. We describe a statistical tool that can be applied to other HESN cohorts to identify individuals with high exposure to HIV-1. RESULTS: HIV-1 exposure was best quantified by frequency of unprotected sex with, plasma HIV-1 RNA levels among, and presence of genital ulcer disease among HIV-1-infected partners and by age, pregnancy status, herpes simplex virus 2 serostatus, and male circumcision status among HESN participants. Overall, 14% of HESN individuals persistently had high HIV-1 exposure and exhibited a declining incidence of HIV-1 infection over time. CONCLUSIONS: A minority of HESN individuals from HIV-1-discordant couples had persistent high HIV-1 exposure over time. Decreasing incidence of infection in this group suggests these individuals were selected for resistance to HIV-1 and may be most appropriate for identifying biological correlates of natural host resistance to HIV-1 infection.

Safety and immunogenicity of a variant-adapted SARS-CoV-2 recombinant protein vaccine with AS03 adjuvant as a booster in adults primed with authorized vaccines: a phase 3, parallel-group study.

Background: In a parallel-group, international, phase 3 study (ClinicalTrials.govNCT04762680), we evaluated prototype (D614) and Beta (B.1.351) variant recombinant spike protein booster vaccines with AS03-adjuvant (CoV2 preS dTM-AS03). Methods: Adults, previously primed with mRNA (BNT162b2, mRNA-1273), adenovirus-vectored (Ad26.CoV2.S, ChAdOx1nCoV-19) or protein (CoV2 preS dTM-AS03 [monovalent D614; MV(D614)]) vaccines were enrolled between 29 July 2021 and 22 February 2022. Participants were stratified by age (18-55 and ≥ 56 years) and received one of the following CoV2 preS dTM-AS03 booster formulations: MV(D614) (n = 1285), MV(B.1.351) (n = 707) or bivalent D614 + B.1.351 (BiV; n = 625). Unvaccinated adults who tested negative on a SARS-CoV-2 rapid diagnostic test (control group, n = 479) received two primary doses, 21 days apart, of MV(D614). Anti-D614G and anti-B.1.351 antibodies were evaluated using validated pseudovirus (lentivirus) neutralization (PsVN) assay 14 days post-booster (day [D]15) in 18-55-year-old BNT162b2-primed participants and compared with those pre-booster (D1) and on D36 in 18-55-year-old controls (primary immunogenicity endpoints). PsVN titers to Omicron BA.1, BA.2 and BA.4/5 subvariants were also evaluated. Safety was evaluated over a 12-month follow-up period. Planned interim analyses are presented up to 14 days post-last vaccination for immunogenicity and over a median duration of 5 months for safety. Findings: All three boosters elicited robust anti-D614G or -B.1.351 PsVN responses for mRNA, adenovirus-vectored and protein vaccine-primed groups. Among BNT162b2-primed adults (18-55 years), geometric means of the individual post-booster versus pre-booster titer ratio (95% confidence interval [CI]) were: for MV (D614), 23.37 (18.58-29.38) (anti-D614G); for MV(B.1.351), 35.41 (26.71-46.95) (anti-B.1.351); and for BiV, 14.39 (11.39-18.28) (anti-D614G) and 34.18 (25.84-45.22 (anti-B.1.351). GMT ratios (98.3% CI) versus post-primary vaccination GMTs in controls, were: for MV(D614) booster, 2.16 (1.69; 2.75) [anti-D614G]; for MV(B.1.351), 1.96 (1.54; 2.50) [anti-B.1.351]; and for BiV, 2.34 (1.84; 2.96) [anti-D614G] and 1.39 (1.09; 1.77) [anti-B.1.351]. All booster formulations elicited cross-neutralizing antibodies against Omicron BA.2 (across priming vaccine subgroups), Omicron BA.1 (BNT162b2-primed participants) and Omicron BA.4/5 (BNT162b2-primed participants and MV D614-primed participants). Similar patterns in antibody responses were observed for participants aged ≥56 years. Reactogenicity tended to be transient and mild-to-moderate severity in all booster groups. No safety concerns were identified. Interpretation: CoV2 preS dTM-AS03 boosters demonstrated acceptable safety and elicited robust neutralizing antibodies against multiple variants, regardless of priming vaccine. Funding: Sanofi and Biomedical Advanced Research and Development Authority (BARDA).

Sexual risk behaviors among HIV-infected South African men and women with their partners in a primary care program: implications for couples-based prevention.

We studied 1163 sexually-active HIV-infected South African men and women in an urban primary care program to understand patterns of sexual behaviors and whether these behaviors differed by partner HIV status. Overall, 40% reported a HIV-positive partner and 60% a HIV-negative or status unknown partner; and 17.5% reported >2 sex acts in the last 2 weeks, 16.4% unprotected sex in the last 6 months, and 3.7% >1 sex partner in the last 6 months. Antiretroviral therapy (ART) was consistently associated with decreased sexual risk behaviors, as well as with reporting a HIV-negative or status unknown partner. The odds of sexual risk behaviors differed by sex; and were generally higher among participants reporting a HIV-positive partner, but continued among those with a HIV-negative or status unknown partner. These data support ART as a means of HIV prevention. Engaging in sexual risk behaviors primarily with HIV-positive partners was not widely practiced in this setting, emphasizing the need for couples-based prevention.

Mortality in members of HIV-1 serodiscordant couples in Africa and implications for antiretroviral therapy initiation: results of analyses from a multicenter randomized trial.

BACKGROUND: The risk of HIV-1 related mortality is strongly related to CD4 count. Guidance on optimal timing for initiation of antiretroviral therapy (ART) is still evolving, but the contribution of HIV-1 infection to excess mortality at CD4 cell counts above thresholds for HIV-1 treatment has not been fully described, especially in resource-poor settings. To compare mortality among HIV-1 infected and uninfected members of HIV-1 serodiscordant couples followed for up to 24 months, we conducted a secondary data analysis examining mortality among HIV-1 serodiscordant couples participating in a multicenter, randomized controlled trial at 14 sites in seven sub-Saharan African countries. METHODS: Predictors of death were examined using Cox regression and excess mortality by CD4 count and plasma HIV-1 RNA was computed using Poisson regression for correlated data. RESULTS: Among 3295 HIV serodiscordant couples, we observed 109 deaths from any cause (74 deaths among HIV-1 infected and 25 among HIV-1 uninfected persons). Among HIV-1 infected persons, the risk of death increased with lower CD4 count and higher plasma viral levels. HIV-1 infected persons had excess mortality due to medical causes of 15.2 deaths/1000 person years at CD4 counts of 250 - 349 cells/µl and 8.9 deaths at CD4 counts of 350 - 499 cells/µl. Above a CD4 count of 500 cells/µl, mortality was comparable among HIV-1 infected and uninfected persons. CONCLUSIONS: Among African serodiscordant couples, there is a high rate of mortality attributable to HIV-1 infection at CD4 counts above the current threshold (200 - 350 cells/µl) for ART initiation in many African countries. These data indicate that earlier initiation of treatment is likely to provide clinical benefit if further expansion of ART access can be achieved. TRIAL REGISTRATION: Clinicaltrials.gov (NCT00194519).

A steady state of CD4+ T cell memory maturation and activation is established during primary subtype C HIV-1 infection.

The functional integrity of CD4(+) T cells is crucial for well-orchestrated immunity and control of HIV-1 infection, but their selective depletion during infection creates a paradox for understanding a protective response. We used multiparameter flow cytometry to measure activation, memory maturation, and multiple functions of total and Ag-specific CD4(+) T cells in 14 HIV-1- and CMV- coinfected individuals at 3 and 12 mo post HIV-1 infection. Primary HIV-1 infection was characterized by elevated levels of CD38, HLA-DR, and Ki67 in total memory and Gag-specific CD4(+) and CD8(+) T cells. In both HIV-infected and 15 uninfected controls, the frequency of activated cells was uniformly distributed among early differentiated (ED; CD45RO(+)CD27(+)), late differentiated (CD45RO(+)CD27(-)), and fully differentiated effector (CD45RO(-)CD27(-)) memory CD4(+) T cells. In HIV-1-infected individuals, activated CD4(+) T cells significantly correlated with viremia at 3 mo postinfection (r = 0.79, p = 0.0007) and also harbored more gag provirus DNA copies than nonactivated cells (p = 0.04). Moreover, Gag-specific ED CD4(+) T cells inversely associated with plasma viral load (r = -0.87, p < 0.0001). Overall, we show that low copy numbers of gag provirus and plasma RNA copies associated with low CD4 activation as well as accumulation of ED HIV-specific CD4(+) memory. Significant positive correlations between 3 and 12 mo activation and memory events highlighted that a steady state of CD4(+) T cell activation and memory maturation was established during primary infection and that these cells were unlikely to be involved in influencing the course of viremia in the first 12 mo of HIV-1 infection.

Analysis of genetic linkage of HIV from couples enrolled in the HIV Prevention Trials Network 052 trial.

BACKGROUND: The HIV Prevention Trials Network (HPTN) 052 trial demonstrated that early initiation of antiretroviral therapy (ART) reduces human immunodeficiency virus (HIV) transmission from HIV-infected adults (index participants) to their HIV-uninfected sexual partners. We analyzed HIV from 38 index-partner pairs and 80 unrelated index participants (controls) to assess the linkage of seroconversion events. METHODS: Linkage was assessed using phylogenetic analysis of HIV pol sequences and Bayesian analysis of genetic distances between pol sequences from index-partner pairs and controls. Selected samples were also analyzed using next-generation sequencing (env region). RESULTS: In 29 of the 38 (76.3%) cases analyzed, the index was the likely source of the partner's HIV infection (linked). In 7 cases (18.4%), the partner was most likely infected from a source other than the index participant (unlinked). In 2 cases (5.3%), linkage status could not be definitively established. CONCLUSIONS: Nearly one-fifth of the seroconversion events in HPTN 052 were unlinked. The association of early ART and reduced HIV transmission was stronger when the analysis included only linked events. This underscores the importance of assessing the genetic linkage of HIV seroconversion events in HIV prevention studies involving serodiscordant couples.

Whole-blood cytokine secretion assay as a high-throughput alternative for assessing the cell-mediated immunity profile after two doses of an adjuvanted SARS-CoV-2 recombinant protein vaccine candidate.

OBJECTIVES: We previously described the Phase I-II evaluation of SARS-CoV-2 recombinant protein candidate vaccine, CoV2-PreS-dTM, with AF03- or AS03-adjuvant systems (ClinicalTrials.gov, NCT04537208). Here, we further characterise the cellular immunogenicity profile of this vaccine candidate using a whole-blood secretion assay in parallel to intracellular cytokine staining (ICS) of cryopreserved peripheral blood mononuclear cells (PBMCs). METHODS: A randomly allocated subset of 90 healthy, SARS-CoV-2-seronegative adults aged ≥ 18 years who had received (random allocation) one or two separate injections (on study day [D]1 and D22) of saline placebo or CoV2-PreS-dTM formulated with AS03 or AF03 were included. Cytokine secretion was assessed using a TruCulture® whole-blood stimulation system in combination with multiplex bead array, and intracellular cytokine profiles were evaluated on thawed PBMCs following ex vivo stimulation with recombinant S protein at pre-vaccination (D1), post-dose 1 (D22) and post-dose 2 (D36). RESULTS: Both methods detected similar vaccine-induced responses after the first and second doses. We observed a Th1 bias (Th1/Th2 ratio > 1.0) for most treatment groups when analysed in whole blood, mainly characterised by increased IFN-γ, IL-2 and TNF-α secretion. Among participants aged ≥ 50 years, the Th1/Th2 ratio was higher for those who received vaccine candidate with AS03 versus AF03 adjuvant. ICS revealed that this higher Th1/Th2 ratio resulted from higher levels of IFN-γ expression and that the vaccine induced polyfunctional CD4+ T cells. CONCLUSIONS: The whole-blood cytokine secretion assay is a high-throughput alternative for assessing the quantity and character of vaccine-induced cellular responses.

Safety and immunogenicity of an AS03-adjuvanted SARS-CoV-2 recombinant protein vaccine (CoV2 preS dTM) in healthy adults: interim findings from a phase 2, randomised, dose-finding, multicentre study.

BACKGROUND: We evaluated our SARS-CoV-2 prefusion spike recombinant protein vaccine (CoV2 preS dTM) with different adjuvants, unadjuvanted, and in a one-injection and two-injection dosing schedule in a previous phase 1-2 study. Based on interim results from that study, we selected a two-injection schedule and the AS03 adjuvant for further clinical development. However, lower than expected antibody responses, particularly in older adults, and higher than expected reactogenicity after the second vaccination were observed. In the current study, we evaluated the safety and immunogenicity of an optimised formulation of CoV2 preS dTM adjuvanted with AS03 to inform progression to phase 3 clinical trial. METHODS: This phase 2, randomised, parallel-group, dose-ranging study was done in adults (≥18 years old), including those with pre-existing medical conditions, those who were immunocompromised (except those with recent organ transplant or chemotherapy) and those with a potentially increased risk for severe COVID-19, at 20 clinical research centres in the USA and Honduras. Women who were pregnant or lactating or, for those of childbearing potential, not using an effective method of contraception or abstinence, and those who had received a COVID-19 vaccine, were excluded. Participants were randomly assigned (1:1:1) using an interactive response technology system, with stratification by age (18-59 years and ≥60 years), rapid serodiagnostic test result (positive or negative), and high-risk medical conditions (yes or no), to receive two injections (day 1 and day 22) of 5 7mu;g (low dose), 10 7mu;g (medium dose), or 15 7mu;g (high dose) CoV2 preS dTM antigen with fixed AS03 content. All participants and outcome assessors were masked to group assignment; unmasked study staff involved in vaccine preparation were not involved in safety outcome assessments. All laboratory staff performing the assays were masked to treatment. The primary safety objective was to describe the safety profile in all participants, for each candidate vaccine formulation. Safety endpoints were evaluated for all randomised participants who received at least one dose of the study vaccine (safety analysis set), and are presented here for the interim study period (up to day 43). The primary immunogenicity objective was to describe the neutralising antibody titres to the D614G variant 14 days after the second vaccination (day 36) in participants who were SARS-CoV-2 naive who received both injections, provided samples at day 1 and day 36, did not have protocol deviations, and did not receive an authorised COVID-19 vaccine before day 36. Neutralising antibodies were measured using a pseudovirus neutralisation assay and are presented here up to 14 days after the second dose. As a secondary immunogenicity objective, we assessed neutralising antibodies in non-naive participants. This trial is registered with ClinicalTrials.gov (NCT04762680) and is closed to new participants for the cohort reported here. FINDINGS: Of 722 participants enrolled and randomly assigned between Feb 24, 2021, and March 8, 2021, 721 received at least one injection (low dose=240, medium dose=239, and high dose=242). The proportion of participants reporting at least one solicited adverse reaction (injection site or systemic) in the first 7 days after any vaccination was similar between treatment groups (217 [91%] of 238 in the low-dose group, 213 [90%] of 237 in the medium-dose group, and 218 [91%] of 239 in the high-dose group); these adverse reactions were transient, were mostly mild to moderate in intensity, and occurred at a higher frequency and intensity after the second vaccination. Four participants reported immediate unsolicited adverse events; two (one each in the low-dose group and medium-dose group) were considered by the investigators to be vaccine related and two (one each in the low-dose and high-dose groups) were considered unrelated. Five participants reported seven vaccine-related medically attended adverse events (two in the low-dose group, one in the medium-dose group, and four in the high-dose group). No vaccine-related serious adverse events and no adverse events of special interest were reported. Among participants naive to SARS-CoV-2 at day 36, 158 (98%) of 162 in the low-dose group, 166 (99%) of 168 in the medium-dose group, and 163 (98%) of 166 in the high-dose group had at least a two-fold increase in neutralising antibody titres to the D614G variant from baseline. Neutralising antibody geometric mean titres (GMTs) at day 36 for participants who were naive were 2189 (95% CI 1744-2746) for the low-dose group, 2269 (1792-2873) for the medium-dose group, and 2895 (2294-3654) for the high-dose group. GMT ratios (day 36: day 1) were 107 (95% CI 85-135) in the low-dose group, 110 (87-140) in the medium-dose group, and 141 (111-179) in the high-dose group. Neutralising antibody titres in non-naive adults 21 days after one injection tended to be higher than titres after two injections in adults who were naive, with GMTs 21 days after one injection for participants who were non-naive being 3143 (95% CI 836-11 815) in the low-dose group, 2338 (593-9226) in the medium-dose group, and 7069 (1361-36 725) in the high-dose group. INTERPRETATION: Two injections of CoV2 preS dTM-AS03 showed acceptable safety and reactogenicity, and robust immunogenicity in adults who were SARS-CoV-2 naive and non-naive. These results supported progression to phase 3 evaluation of the 10 7mu;g antigen dose for primary vaccination and a 5 7mu;g antigen dose for booster vaccination. FUNDING: Sanofi Pasteur and Biomedical Advanced Research and Development Authority.