Perspectives of people with HIV on implementing long acting cabotegravir plus rilpivirine in clinics and community settings in the UK: results from the anti-sexist, anti-racist, anti-ageist ILANA study.

INTRODUCTION: The equity-focused ILANA study evaluated feasibility, acceptability, appropriateness of delivering on-label two-monthly cabotegravir and rilpivirine (CAB+RPV) injections for HIV-1 therapy in clinics and community settings. METHODS: The study, which mandated inclusive recruitment, was conducted May-December 2022 at six UK sites. Injections were delivered in clinic (months 1-6), and in clinic or community setting according to patient choice (months 6-12). Surveys were completed at baseline, M4 and M12 using validated measures for feasibility (FIM), acceptability (AIM), and appropriateness (IAM). Primary endpoint: proportion of participants agreeing that the injection and community setting were feasible (FIM>4) at M12. Fourteen participants completed interviews at baseline and M12. RESULTS: Community settings offered by sites included: home visits (n=3), HIV support organisations (n=2), community clinic (n=1). Of 114 participants,54% were female, 70% racially minoritised and 40% aged >50. 27/114 chose to receive injections in community settings. FIM/AIM/IAM scores at M12 were high for the injection (79.0-87.4%) and lower for the community setting (44.2-47.4%) overall. Subgroup analyses indicated differences in scores by gender and ethnicity. Among those who attended the community, FIM/AIM/IAM scores for the community setting at M12 were high (73.1-80.8%). Concerns about stigma, inconvenience, and losing access to trusted clinicians negatively influenced perceptions of receiving injections at community settings, amongst other factors. CONCLUSION: CAB+RPV injections were considered highly feasible, acceptable, and appropriate, however few chose community delivery. Those that chose community delivery found it highly acceptable and feasible. Further exploration of CAB+RPV delivery in alternative community sites not offered (e.g. primary care or pharmacies) is warranted.

Cardiovascular disease risk in people of African ancestry with HIV in the United Kingdom.

OBJECTIVES: Our objective was to describe the prevalence of cardiovascular disease (CVD) risk factors in people of African ancestry with HIV in the UK. METHODS: We conducted a cross-sectional analysis of CVD risk factors in Black people with HIV aged ≥40 years and estimated the 10-year CVD risk using QRISK®3-2018. Correlations between body mass index (BMI) and CVD risk factors were described using Pearson correlation coefficients, and factors associated with 10-year CVD risk ≥5% were described using logistic regression. RESULTS: We included 833 Black people with HIV and a median age of 54 years; 54% were female, 50% were living with obesity (BMI ≥30 kg/m2), 61% had hypertension, and 19% had diabetes mellitus. CVD risk >5% ranged from 2% in female participants aged 40-49 years to 99% in men aged ≥60 years, and use of statins ranged from 7% in those with CVD risk <2.5% to 64% in those with CVD risk ≥20%. BMI was correlated (R2 0.1-0.2) with triglycerides and diastolic blood pressure in women and with glycated haemoglobin, systolic and diastolic blood pressure, and total:high-density lipoprotein (HDL) cholesterol ratio in men. In both female and male participants, older age, blood pressure, diabetes mellitus, and kidney disease were strongly associated with CVD risk ≥5%, whereas obesity, total:HDL cholesterol, triglycerides, and smoking status were variably associated with CVD risk ≥5%. CONCLUSIONS: We report a high burden of CVD risk factors, including obesity, hypertension, and diabetes mellitus, in people of African ancestry with HIV in the UK. BMI-focused interventions in these populations may improve CVD risk while also addressing other important health issues.

Impact of antiretroviral therapy during primary HIV infection on T-cell immunity after treatment interruption.

This study aims to understand the impact of early antiretroviral therapy (ART) on HIV-specific T-cell responses measured after treatment interruption may inform strategies to deliver ART-free immune-mediated viral suppression. HIV-specific T-cell immunity was analysed using gamma interferon enzyme-linked immunospot assays in two studies. SPARTAC included individuals with primary HIV infection randomised to 48 weeks of ART (n = 24) or no immediate therapy (n = 37). The PITCH (n = 7) cohort started antiretroviral therapy in primary infection for at least one year, followed by TI. In SPARTAC, participants treated in PHI for 48 weeks followed by TI for 12 weeks, and those who remained untreated for 60 weeks made similar HIV Gag-directed responses (both magnitude and breadth) at week 60. However, the treated group made a greater proportion of novel HIV Gag-directed responses by Week 60, suggestive of a greater reserve to produce new potentially protective responses. In the more intensively followed PITCH study, 6/7 participants showed dominant Gag and/or Pol-specific responses post-TI compared with pre-TI. Although early ART in PHI was not associated with major differences in HIV-specific immunity following TI compared with untreated participants, the potential to make more new Gag-directed responses warrants further investigation as this may inform strategies to achieve ART-free control.

Activating FcγRs on monocytes are necessary for optimal Mayaro virus clearance.

Mayaro virus (MAYV) is an emerging arbovirus. Previous studies have shown antibody Fc effector functions are critical for optimal monoclonal antibody-mediated protection against alphaviruses; however, the requirement of Fc gamma receptors (FcγRs) for protection during natural infection has not been evaluated. Here, we showed mice lacking activating FcγRs (FcRγ-/-) developed prolonged clinical disease with more virus in joint-associated tissues. Viral clearance was associated with anti-MAYV cell surface binding rather than neutralizing antibodies. Lack of Fc-FcγR engagement increased the number of monocytes through chronic timepoints. Single cell RNA sequencing showed elevated levels of pro-inflammatory monocytes in joint-associated tissue with increased MAYV RNA present in FcRγ-/- monocytes and macrophages. Transfer of FcRγ-/- monocytes into wild type animals was sufficient to increase virus in joint-associated tissue. Overall, this study suggests that engagement of antibody Fc with activating FcγRs promotes protective responses during MAYV infection and prevents monocytes from being potential targets of infection.

Recombinant OC43 SARS-CoV-2 spike replacement virus: An improved BSL-2 proxy virus for SARS-CoV-2 neutralization assays.

We generated a replication-competent OC43 human seasonal coronavirus (CoV) expressing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike in place of the native spike (rOC43-CoV2 S). This virus is highly attenuated relative to OC43 and SARS-CoV-2 in cultured cells and animals and is classified as a biosafety level 2 (BSL-2) agent by the NIH biosafety committee. Neutralization of rOC43-CoV2 S and SARS-CoV-2 by S-specific monoclonal antibodies and human sera is highly correlated, unlike recombinant vesicular stomatitis virus-CoV2 S. Single-dose immunization with rOC43-CoV2 S generates high levels of neutralizing antibodies against SARS-CoV-2 and fully protects human ACE2 transgenic mice from SARS-CoV-2 lethal challenge, despite nondetectable replication in respiratory and nonrespiratory organs. rOC43-CoV2 S induces S-specific serum and airway mucosal immunoglobulin A and IgG responses in rhesus macaques. rOC43-CoV2 S has enormous value as a BSL-2 agent to measure S-specific antibodies in the context of a bona fide CoV and is a candidate live attenuated SARS-CoV-2 mucosal vaccine that preferentially replicates in the upper airway.

MAVMET trial: maraviroc and/or metformin for metabolic dysfunction associated fatty liver disease in adults with suppressed HIV.

OBJECTIVE: Metabolic dysfunction associated fatty liver disease (MAFLD) is over-represented in people with HIV (PWH). Maraviroc (MVC) and/or metformin (MET) may reduce MAFLD by influencing inflammatory pathways and fatty acid metabolism. DESIGN: Open-label, 48-week randomized trial with a 2 x 2 factorial design. SETTING: Multicenter HIV clinics. PARTICIPANTS: Nondiabetic, virologically suppressed PLWH, aged at least 35 years, with confirmed/suspected MAFLD (≥1 biochemical/anthropometric/radiological/histological features). INTERVENTION: Adjunctive MVC; MET; MVC+MET vs. antiretroviral therapy (ART) alone. PRIMARY OUTCOME: Change in liver fat fraction (LFF) between baseline and week-48 using magnetic resonance proton density fat fraction (MR PDFF). RESULTS: Six sites enrolled 90 participants (93% male; 81% white; median age 52 [interquartile range, IQR 47-57] years) between March 19, 2018, and November 11, 2019. Seventy percent had imaging/biopsy and at least one 1 MAFLD criteria. The analysis included 82/90 with week-0 and week-48 scans. Median baseline MR PDFF was 8.9 (4.6-17.1); 40, 38, 8, and 14% had grade zero, one, two, and three steatosis, respectively. Mean LFF increased slightly between baseline and follow-up scans: 2.22% MVC, 1.26% MET, 0.81% MVC+MET, and 1.39% ART alone. Prolonged intervention exposure (delayed week-48 scans) exhibited greater increases in MR PDFF (estimated difference 4.23% [95% confidence interval, 95% CI 2.97-5.48], P  < 0.001). There were no differences in predicted change for any intervention compared to ART alone: MVC (-0.42% [95% CI -1.53 to 0.68, P  = 0.45]), MET (-0.62 [-1.81 to 0.56, P  = 0.30]), and MVC+MET (-1.04 [-2.74 to 0.65, P  = 0.23]). Steatosis grade remained unchanged in 55% and increased in 24%. CONCLUSION: Baseline levels of liver fat were lower than predicted. Contrary to our hypothesis, neither MVC, MET, or the combination significantly reduced liver fat as measured by MRPDFF compared to ART alone.

Practical considerations for using low-cost sensors to assess wildfire smoke exposure in school and childcare settings.

BACKGROUND: More frequent and intense wildfires will increase concentrations of smoke in schools and childcare settings. Low-cost sensors can assess fine particulate matter (PM2.5) concentrations with high spatial and temporal resolution. OBJECTIVE: We sought to optimize the use of sensors for decision-making in schools and childcare settings during wildfire smoke to reduce children's exposure to PM2.5. METHODS: We measured PM2.5 concentrations indoors and outdoors at four schools in Washington State during wildfire smoke in 2020-2021 using low-cost sensors and gravimetric samplers. We randomly sampled 5-min segments of low-cost sensor data to create simulations of brief portable handheld measurements. RESULTS: During wildfire smoke episodes (lasting 4-19 days), median hourly PM2.5 concentrations at different locations inside a single facility varied by up to 49.6 µg/m3 (maximum difference) during school hours. Median hourly indoor/outdoor ratios across schools ranged from 0.22 to 0.91. Within-school differences in concentrations indicated that it is important to collect measurements throughout a facility. Simulation results suggested that making handheld measurements more often and over multiple days better approximates indoor/outdoor ratios for wildfire smoke. During a period of unstable air quality, PM2.5 over the next hour indoors was more highly correlated with the last 10-min of data (mean R2 = 0.94) compared with the last 3-h (mean R2 = 0.60), indicating that higher temporal resolution data is most informative for decisions about near-term activities indoors. IMPACT STATEMENT: As wildfires continue to increase in frequency and severity, staff at schools and childcare facilities are increasingly faced with decisions around youth activities, building use, and air filtration needs during wildfire smoke episodes. Staff are increasingly using low-cost sensors for localized outdoor and indoor PM2.5 measurements, but guidance in using and interpreting low-cost sensor data is lacking. This paper provides relevant information applicable for guidance in using low-cost sensors for wildfire smoke response.

Prevalence of resistance-associated viral variants to the HIV-specific broadly neutralising antibody 10-1074 in a UK bNAb-naïve population.

Broadly neutralising antibodies (bNAbs) targeting HIV show promise for both prevention of infection and treatment. Among these, 10-1074 has shown potential in neutralising a wide range of HIV strains. However, resistant viruses may limit the clinical efficacy of 10-1074. The prevalence of both de novo and emergent 10-1074 resistance will determine its use at a population level both to protect against HIV transmission and as an option for treatment. To help understand this further, we report the prevalence of pre-existing mutations associated with 10-1074 resistance in a bNAb-naive population of 157 individuals presenting to UK HIV centres with primary HIV infection, predominantly B clade, receiving antiretroviral treatment. Single genome analysis of HIV proviral envelope sequences showed that 29% of participants' viruses tested had at least one sequence with 10-1074 resistance-associated mutations. Mutations interfering with the glycan binding site at HIV Env position 332 accounted for 95% of all observed mutations. Subsequent analysis of a larger historic dataset of 2425 B-clade envelope sequences sampled from 1983 to 2019 revealed an increase of these mutations within the population over time. Clinical studies have shown that the presence of pre-existing bNAb mutations may predict diminished therapeutic effectiveness of 10-1074. Therefore, we emphasise the importance of screening for these mutations before initiating 10-1074 therapy, and to consider the implications of pre-existing resistance when designing prevention strategies.

HIV outcomes during the COVID-19 pandemic in people of Black ethnicities living with HIV in England.

OBJECTIVES: To describe HIV care outcomes in people of Black ethnicities living in England during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; coronavirus disease 2019 [COVID-19]) pandemic. METHODS: This was an observational cohort study of people of self-reported Black ethnicities attending for HIV care at nine HIV clinics across England. The primary outcome was a composite of antiretroviral therapy (ART) interruption and HIV viraemia (HIV RNA ≥200 copies/mL) ascertained via self-completed questionnaires and review of medical records. We used multivariable logistic regression to explore associations between ART interruption/HIV viraemia and demographic factors, pre-pandemic HIV immunovirological control, comorbidity status, and COVID-19 disease and vaccination status. RESULTS: We included 2290 people (median age 49.3 years; 56% female; median CD4 cell count 555 cells/mm3; 92% pre-pandemic HIV RNA <200 copies/mL), of whom 302 (13%) reported one or more ART interruption, 312 (14%) had documented HIV viraemia ≥200 copies/mL, and 401 (18%) experienced the composite endpoint of ART interruption/HIV viraemia. In multivariable analysis, a pre-pandemic HIV RNA <200 copies/mL (odds ratio [OR] 0.21; 95% confidence interval [CI] 0.15-0.30) and being vaccinated against SARS-CoV-2 (OR 0.41; 95% CI 0.30-0.55) were associated with reduced odds of ART interruption/HIV viraemia; pandemic-related disruptions to HIV care were common self-reported additional factors. CONCLUSIONS: During the COVID-19 pandemic, one in six people of Black ethnicities in this HIV cohort experienced an ART interruption/HIV viraemia. Some of these episodes resulted from pandemic-related healthcare disruptions. Associations with suboptimal engagement in HIV care pre-pandemic and not being vaccinated against SARS-CoV-2 suggest that wider health beliefs and/or poor healthcare access may have been contributory factors.

Waist circumference and cardiometabolic parameters in people of African/Caribbean ancestry with HIV in South London (CKD-AFRICA study).

BACKGROUND: There are no validated waist circumference (WC) cut-offs to define metabolic syndrome in Black people with HIV. METHODS: Cross-sectional analyses within the CKD-AFRICA study. We used Pearson correlation coefficients and receiver operating characteristic (ROC) curves to describe the relationship between WC and cardiometabolic parameters including triglycerides, cholesterol, glucose, glycated haemoglobin (HbA1c), and homeostatic model assessment for insulin resistance (HOMA-IR), and to identify optimal WC cut-offs for each of these outcomes. RESULTS: We included 383 participants (55% female, median age 52 years) with generally well controlled HIV. Female and male participants had similar WC (median 98 vs. 97 cm, p = .16). Generally weak correlations (r2 < 0.2) between WC and other cardiometabolic parameters were observed, with low (<0.7) areas under the ROC curves. The optimal WC cut-offs for constituents of the metabolic syndrome, HbA1c and HOMA-IR ranged from 92 to 101 cm in women and 89-98 cm in men, respectively; these cut-offs had variable sensitivity (52%-100%) and generally poor specificity (28%-72%). CONCLUSIONS: In this cohort of Black people with HIV, WC cut-offs for cardiometabolic risk factors in male participants were in line with the recommended value of 94 cm while in female participants they vastly exceeded the recommended 80 cm for white women.

Long-term efficacy and safety of a treatment strategy for HIV infection using protease inhibitor monotherapy: 8-year routine clinical care follow-up from a randomised, controlled, open-label pragmatic trial (PIVOT).

Background: Treatment-simplification strategies are important tools for patient-centred management. We evaluated long-term outcomes from a PI monotherapy switch strategy. Methods: Eligible participants attending 43 UK treatment centres had a viral load (VL) below 50 copies/ml for at least 24 weeks on combination ART. Participants were randomised to maintain ongoing triple therapy (OT) or switch to a strategy of physician-selected PI monotherapy (PI-mono) with prompt return to combination therapy if VL rebounded. The primary outcome, previously reported, was loss of future drug options after 3 years, defined as new intermediate/high level resistance to at least one drug to which the participant's virus was considered sensitive at trial entry. Here we report resistance and disease outcomes after further extended follow-up in routine care. The study was registered as ISRCTN04857074. Findings: We randomised 587 participants to OT (291) or PI-mono (296) between Nov 4, 2008, and July 28, 2010 and followed them for a median of more than 8 years (100 months) until 2018. At the end of this follow-up time, one or more future drug options had been lost in 7 participants in the OT group and 6 in the PI-mono group; estimated cumulative risk by 8 years of 2.7% and 2.1% respectively (difference -0.6%, 95% CI -3.2% to 2.0%). Only one PI-mono participant developed resistance to the protease inhibitor they were taking (atazanavir). Serious clinical events (death, serious AIDS, and serious non-AIDS) were infrequent; reported in a total of 12 (4.1%) participants in the OT group and 23 (7.8%) in the PI-mono group (P = 0.08) over the entire follow-up period. Interpretation: A strategy of PI monotherapy, with regular VL monitoring and prompt reintroduction of combination treatment following rebound, preserved future treatment options. Findings confirm the high genetic barrier to resistance of the PI drug class that makes them well suited for creative, patient-centred, treatment-simplification approaches. The possibility of a small excess risk of serious clinical events with the PI monotherapy strategy cannot be excluded. Funding: The National Institute for Health Research Health Technology Assessment programme.

Clinical epidemiology of COVID-19 in people of black ethnicity living with HIV in the UK.

OBJECTIVES: To describe the clinical epidemiology of COVID-19 in people of black ethnicity living with HIV in the UK. METHODS: We investigated the incidence and factors associated with COVID-19 in a previously established and well-characterized cohort of black people with HIV. Primary outcomes were COVID-19 acquisition and severe COVID-19 disease (requiring hospitalization and/or resulting in death). Cumulative incidence was analysed using Nelson-Aalen methods, and associations between demographic, pre-pandemic immune-virological parameters, comorbidity status and (severe) COVID-19 were identified using Cox regression analysis. RESULTS: COVID-19 status was available for 1847 (74%) of 2495 COVID-AFRICA participants (median age 49.6 years; 56% female; median CD4 cell count = 555 cells/µL; 93% HIV RNA <200 copies/mL), 573 (31%) of whom reported at least one episode of COVID-19. The cumulative incidence rates of COVID-19 and severe COVID-19 were 31.0% and 3.4%, respectively. Region of ancestry (East/Southern/Central vs. West Africa), nadir CD4 count and kidney disease were associated with COVID-19 acquisition. Diabetes mellitus [adjusted hazard ratio (aHR) = 2.39, 95% confidence interval (CI): 1.26-4.53] and kidney disease (aHR = 2.53, 95% CI: 1.26-4.53) were associated with an increased risk, and recent CD4 count >500 cells/µL (aHR = 0.49, 95% CI: 0.25-0.93) with a lower risk of severe COVID-19. CONCLUSIONS: Region of ancestry was associated with COVID-19 acquisition, and immune and comorbidity statuses were associated with COVID-19 disease severity in people of black ethnicity living with HIV in the UK.

Associations between social determinants of health and comorbidity and multimorbidity in people of black ethnicities with HIV.

OBJECTIVE: Social determinants of health (SDH) are important determinants of long-term conditions and multimorbidity in the general population. The intersecting relationship between SDH and multimorbidity in people with HIV remains poorly studied. DESIGN: A cross-sectional study investigating the relationships between eight socio-economic parameters and prevalent comorbidities of clinical significance and multimorbidity in adults of African ancestry with HIV aged 18-65 years in South London, UK. METHODS: Multivariable logistic regression analysis was used to evaluate associations between SDH and comorbidities and multimorbidity. RESULTS: Between September 2020 and January 2022, 398 participants (median age 52 years, 55% women) were enrolled; 85% reported at least one SDH and 72% had at least one comorbidity. There were no associations between SDH and diabetes mellitus or kidney disease, few associations between SDH (job and food insecurity) and cardiovascular or lung disease, and multiple associations between SDH (financial, food, housing and job insecurity, low educational level, social isolation, and discrimination) and poor mental health or chronic pain. Associations between SDH and multimorbidity mirrored those for constituent comorbidities. CONCLUSION: We demonstrate strong associations between SDH and poor mental health, chronic pain and multimorbidity in people of black ethnicities living with HIV in the UK. These findings highlight the likely impact of enduring socioeconomic hardship in these communities and underlines the importance of holistic health and social care for people with HIV to address these adverse psychosocial conditions.

Post-hospitalization remote monitoring for patients with heart failure or chronic obstructive pulmonary disease in an accountable care organization.

BACKGROUND: Post-hospitalization remote patient monitoring (RPM) has potential to improve health outcomes for high-risk patients with chronic medical conditions. The purpose of this study is to determine the extent to which RPM for patients with congestive heart failure (CHF) and chronic obstructive pulmonary disease (COPD) is associated with reductions in post-hospitalization mortality, hospital readmission, and ED visits within an Accountable Care Organization (ACO). METHODS: Nonrandomized prospective study of patients in an ACO offered enrollment in RPM upon hospital discharge between February 2021 and December 2021. RPM comprised of vital sign monitoring equipment (blood pressure monitor, scale, pulse oximeter), tablet device with symptom tracking software and educational material, and nurse-provided oversight and triage. Expected enrollment was for at least 30-days of monitoring, and outcomes were followed for 6 months following enrollment. The co-primary outcomes were (a) the composite of death, hospital admission, or emergency care visit within 180 days of eligibility, and (b) time to occurrence of this composite. Secondary outcomes were each component individually, the composite of death or hospital admission, and outpatient office visits. Adjusted analyses involved doubly robust estimation to address confounding by indication. RESULTS: Of 361 patients offered remote monitoring (251 with CHF and 110 with COPD), 140 elected to enroll (106 with CHF and 34 with COPD). The median duration of RPM-enrollment was 54 days (IQR 34-85). Neither the 6-month frequency of the co-primary composite outcome (59% vs 66%, FDR p-value = 0.47) nor the time to this composite (median 29 vs 38 days, FDR p-value = 0.60) differed between the groups, but 6-month mortality was lower in the RPM group (6.4% vs 17%, FDR p-value = 0.02). After adjustment for confounders, RPM enrollment was associated with nonsignificantly decreased odds for the composite outcome (adjusted OR [aOR] 0.68, 99% CI 0.25-1.34, FDR p-value 0.30) and lower 6-month mortality (aOR 0.41, 99% CI 0.00-0.86, FDR p-value 0.20). CONCLUSIONS: RPM enrollment may be associated with improved health outcomes, including 6-month mortality, for selected patient populations.

Rapid antiretroviral therapy in primary HIV-1 infection enhances immune recovery.

OBJECTIVE: We present findings from a large cohort of individuals treated during primary HIV infection (PHI) and examine the impact of time from HIV-1 acquisition to antiretroviral therapy (ART) initiation on clinical outcomes. We also examine the temporal changes in the demographics of individuals presenting with PHI to inform HIV-1 prevention strategies. METHODS: Individuals who fulfilled the criteria of PHI and started ART within 3 months of confirmed HIV-1 diagnosis were enrolled between 2009 and 2020. Baseline demographics of those diagnosed between 2009 and 2015 (before preexposure prophylaxis (PrEP) and universal ART availability) and 2015-2020 (post-PrEP and universal ART availability) were compared. We examined the factors associated with immune recovery and time to viral suppression. RESULTS: Two hundred four individuals enrolled, 144 from 2009 to 2015 and 90 from 2015 to 2020; median follow-up was 33 months. At PHI, the median age was 33 years; 4% were women, 39% were UK-born, and 84% were MSM. The proportion of UK-born individuals was 47% in 2009-2015, compared with 29% in 2015-2020. There was an association between earlier ART initiation after PHI diagnosis and increased immune recovery; each day that ART was delayed was associated with a lower likelihood of achieving a CD4 + cell count more than 900 cells/µl [hazard ratio 0.99 (95% confidence interval, 95% CI 0.98-0.99), P  = 0.02) and CD4/CD8 more than 1.0 (hazard ratio 0.98 (95% CI 0.97-0.99). CONCLUSION: Early initiation of ART at PHI diagnosis is associated with enhanced immune recovery, providing further evidence to support immediate ART in the context of PHI. Non-UK-born MSM accounts for an increasing proportion of those with primary infection; UK HIV-1 prevention strategies should better target this group.

Bacterial microbiome and host inflammatory gene expression in foreskin tissue.

The penile epithelial microbiome remains underexplored. We sequenced human RNA and a segment of the bacterial 16S rRNA gene from the foreskin tissue of 144 adolescents from South Africa and Uganda collected during penile circumcision after receipt of 1-2 doses of placebo, emtricitabine + tenofovir disoproxil fumarate, or emtricitabine + tenofovir alafenamide to investigate the microbiome of foreskin tissue and its potential changes with antiretroviral use. We identified a large number of anaerobic species, including Corynebacterium acnes, which was detected more frequently in participants from South Africa than Uganda. Bacterial populations did not differ by treatment received, and no differentially abundant taxa were identified between placebo versus active drug recipients. The relative abundance of specific bacterial taxa was negatively correlated with expression of genes downstream of the innate immune response to bacteria and regulation of inflammation. Our results show no difference in the tissue microbiome of the foreskin with short-course antiretroviral use but that bacterial taxa were largely inversely correlated with inflammatory gene expression, consistent with commensal colonization.

Ex vivo challenge models for infectious diseases.

Traditionally, molecular mechanisms of pathogenesis for infectious agents were studied in cell culture or animal models but have limitations on the extent to which the resulting data reflect natural infection in humans. The COVID-19 pandemic has highlighted the urgent need to rapidly develop laboratory models that enable the study of host-pathogen interactions, particularly the relative efficacy of preventive measures. Recently, human and animal ex vivo tissue challenge models have emerged as a promising avenue to study immune responses, screen potential therapies and triage vaccine candidates. This approach offers the opportunity to closely approximate human disease from the perspective of pathology and immune response. It has advantages compared to animal models which are expensive, lengthy and often require containment facilities. Herein, we summarize some recent advances in the development of ex vivo tissue challenge models for COVID-19, HIV-1 and other pathogens. We focus on the contribution of these models to enhancing knowledge of host-pathogen interactions, immune modulation, and their value in testing therapeutic agents. We further highlight the advantages and limitations of using ex vivo challenge models and briefly summarize how the use of organoids provides a useful advancement over current approaches. Collectively, these developments have enormous potential for the study of infectious diseases.

Preferences for oral PrEP dosing among adolescent boys and young men in three sub-Saharan African countries.

BACKGROUND: HIV remains a leading contributor to the disease burden in sub-Saharan Africa, with adolescents and young people disproportionately affected. Optimising pre-exposure prophylaxis (PrEP) uptake has predominantly focused on women and adult men who have sex with men. We explore adolescent boys and young men's PrEP uptake preferences in South Africa, Uganda, and Zimbabwe. METHODS: A cross-sectional sequential exploratory mixed-methods study amongst males aged 13-24 years was conducted between April and September 2019 as part of the CHAPS trial. Group discussions (GDs) and In-Depth Interviews (IDIs) focused on motivations and hindrances for HIV testing, PrEP preference, and reasons for the uptake of PrEP. A thematic approach was used to analyse the qualitative data. A quantitative survey following the qualitative work covered questions on demographics, HIV risk and PrEP preferences (on-demand vs. daily). For quantitative analysis, we fitted logistic regression models to determine factors associated with on-demand vs daily PrEP preference. RESULTS: Overall, 647 adolescent boys and young men (median age 20, IQR: 17-22) were enrolled. Of these, 422 (65.22%) preferred on-demand PrEP (South Africa 45.45%, Uganda 76.80%, Zimbabwe 70.35%; p<0.001). Factors independently associated with on-demand PrEP included country (South Africa, adjusted odds ratio (aOR) = 0.19 [95%CI:0.1-0.3] compared to Uganda) and advanced planning of sex [>24 hours in advance aOR = 1.4 (0.9-2.3) compared to <2 hours]. Qualitatively, participants commonly believed they were not at risk of HIV acquisition most of the time and thought that on-demand PrEP would be suitable as they tend to plan sexual activity in advance. CONCLUSION: Preference for on-demand PrEP is high in young males. The qualitative data support a preference for on-demand PrEP in those who plan sex in advance. HIV intervention programs should offer both on-demand and daily PrEP to engage more adolescent boys and young men in HIV prevention practices.

Broad and potent neutralizing antibodies are elicited in vaccinated individuals following Delta/BA.1 breakthrough infection.

IMPORTANCE: With the emergence of SARS-CoV-2 viral variants, there has been an increase in infections in vaccinated individuals. Here, we isolated monoclonal antibodies (mAbs) from individuals experiencing a breakthrough infection (Delta or BA.1) to determine how exposure to a heterologous Spike broadens the neutralizing antibody response at the monoclonal level. All mAbs isolated had reactivity to the Spike of the vaccine and infection variant. While many mAbs showed reduced neutralization of current circulating variants, we identified mAbs with broad and potent neutralization of BA.2.75.2, XBB, XBB.1.5, and BQ.1.1 indicating the presence of conserved epitopes on Spike. These results indicate that variant-based vaccine boosters have the potential to broaden the vaccine response.

Evaluation of a human mucosal tissue explant model for SARS-CoV-2 replication.

With the onset of COVID-19, the development of ex vivo laboratory models became an urgent priority to study host-pathogen interactions in response to the pandemic. In this study, we aimed to establish an ex vivo mucosal tissue explant challenge model for studying SARS-CoV-2 infection and replication. Nasal or oral tissue samples were collected from eligible participants and explants generated from the tissue were infected with various SARS-CoV-2 strains, including IC19 (lineage B.1.13), Beta (lineage B.1.351) and Delta (lineage B.1.617.2). A qRT-PCR assay used to measure viral replication in the tissue explants over a 15-day period, demonstrated no replication for any viral strains tested. Based on this, the ex vivo challenge protocol was modified by reducing the viral infection time and duration of sampling. Despite these changes, viral infectivity of the nasal and oral mucosa was not improved. Since 67% of the enrolled participants were already vaccinated against SARS-CoV-2, it is possible that neutralizing antibodies in explant tissue may have prevented the establishment of infection. However, we were unable to optimize plaque assays aimed at titrating the virus in supernatants from both infected and uninfected tissue, due to limited volume of culture supernatant available at the various collection time points. Currently, the reasons for the inability of these mucosal tissue samples to support replication of SARS-CoV-2 ex vivo remains unclear and requires further investigation.