Challenges in assessing the immunization status of adults in Germany-lessons from a population-based VACCELERATE survey on polio vaccination.

PURPOSE: Considering the re-emergence of poliomyelitis (PM) in non-endemic regions, it becomes apparent that vaccine preventable diseases can rapidly develop epi- or even pandemic potential. Evaluation of the current vaccination status is required to inform patients, health care providers and policy makers about vaccination gaps. METHODS: Between October 28 2022 and November 23 2022, 5,989 adults from the VACCELEREATE Volunteer Registry completed an electronic case report form on their previous PM vaccine doses including number, types/-valencies and the time of administration based on their vaccination records. A uni-/multivariable regression analysis was performed to assess associations in participant characteristics and immunization status. RESULTS: Among German volunteers (n = 5,449), complete PM immunization schedule was found in 1,981 (36%) participants. Uncertain immunization, due to unknown previous PM vaccination (n = 313, 6%), number of doses (n = 497, 9%), types/-valencies (n = 1,233, 23%) or incoherent immunization schedule (n = 149, 3%) was found in 40% (n = 2,192). Out of 1,276 (23%) participants who reported an incomplete immunization schedule, 62 (1%) never received any PM vaccine. A total of 5,074 (93%) volunteers reported having been vaccinated at least once and 2,087 (38%) indicated that they received vaccination within the last ten years. Female sex, younger age, as well as availability of first vaccination record were characteristics significantly associated with complete immunization (p < 0.001). CONCLUSION: Full PM immunization schedule was low and status frequently classified as uncertain due to lack of details on administered doses. There is an obviousneed for improved recording to enable long-term access to detailed vaccination history in the absence of a centralized immunization register.

Predicting the next pandemic: VACCELERATE ranking of the WorldHealth Organization's Blueprint forAction toPreventEpidemics.

INTRODUCTION: The World Health Organization (WHO)'s Research and Development (R&D) Blueprint for Action to Prevent Epidemics, a plan of action, highlighted several infectious diseases as crucial targets for prevention. These infections were selected based on a thorough assessment of factors such as transmissibility, infectivity, severity, and evolutionary potential. In line with this blueprint, the VACCELERATE Site Network approached infectious disease experts to rank the diseases listed in the WHO R&D Blueprint according to their perceived risk of triggering a pandemic. VACCELERATE is an EU-funded collaborative European network of clinical trial sites, established to respond to emerging pandemics and enhance vaccine development capabilities. METHODS: Between February and June 2023, a survey was conducted using an online form to collect data from members of the VACCELERATE Site Network and infectious disease experts worldwide. Participants were asked to rank various pathogens based on their perceived risk of causing a pandemic, including those listed in the WHO R&D Blueprint and additional pathogens. RESULTS: A total of 187 responses were obtained from infectious disease experts representing 57 countries, with Germany, Spain, and Italy providing the highest number of replies. Influenza viruses received the highest rankings among the pathogens, with 79 % of participants including them in their top rankings. Disease X, SARS-CoV-2, SARS-CoV, and Ebola virus were also ranked highly. Hantavirus, Lassa virus, Nipah virus, and henipavirus were among the bottom-ranked pathogens in terms of pandemic potential. CONCLUSION: Influenza, SARS-CoV, SARS-CoV-2, and Ebola virus were found to be the most concerning pathogens with pandemic potential, characterised by transmissibility through respiratory droplets and a reported history of epidemic or pandemic outbreaks.

Associations between host microbiome and inflammation suggest role for host microbiome in driving COVID-19 disease severity.

Systemic inflammation and innate immune activation are associated with COVID-19 disease severity. Knowledge gaps remain in the relationships between microbiome, inflammation and COVID-19 disease severity. To better characterise these associations, we performed 16SrDNA analysis of stool samples in COVID-19 subjects to explore diversity and taxanomic composition. We correlated these to host inflammatory profiles, derived from soluble plasma biomarkers measured by bead-based fluorescence and electrochemiluminescence immunoassays. Associations of microbial diversity and inflammatory biomarkers on maximal COVID-19 severity (mild, moderate v severe/critical) was explored using logistic regression and weighted gene correlation network analysis (WGCNA). Of 79 subjects, 58% were male and 88% were Caucasian with 36% experiencing mild disease, 22% moderate disease and 40% critical/severe COVID-19. Hierarchical clustering and principal component analysis (PCo) revealed distinct inflammatory clusters that were found to correlate with 4 modules of microbiome profiles. Modules 3 and 4 were associated with both older age and severe/critical disease outcomes. These modules were enriched in pathogenic and inflammatory bacteria that mapped to a pro-inflammatory biomarker cluster. In contrast, module 1 exhibited enrichment of anti-inflammatory bacteria, was associated with younger age and mild/moderate disease outcomes and mapped to a less-inflamed biomarker cluster. This study provides further insights into links between host microbiome, inflammatory responses to SARS-CoV-2 infection and clinical COVID-19 disease severity, suggesting a role for the microbiome in shaping distinct host inflammatory responses to infection.

The Challenges of Vaccine Trial Participation among Underserved and Hard-to-Reach Communities: An Internal Expert Consultation of the VACCELERATE Consortium.

Underserved and hard-to-reach population groups are under-represented in vaccine trials. Thus, we aimed to identify the challenges of vaccine trial participation of these groups in member countries of the VACCELERATE network. Seventeen National Coordinators (NC), each representing their respective country (15 European countries, Israel, and Turkey), completed an online survey. From 15 eligible groups, those that were more frequently declared underserved/hard-to-reach in vaccine research were ethnic minorities (76.5%), persons experiencing homelessness (70.6%), illegal workers and refugees (64.7%, each). When prioritization for education on vaccine trials was considered, ethnic groups, migrants, and immigrants (5/17, 29.4%) were the groups most frequently identified by the NC as top targets. The most prominent barriers in vaccine trial participation affecting all groups were low levels of health literacy, reluctance to participate in trials due to engagement level, and low levels of trust in vaccines/vaccinations. This study highlighted population groups considered underserved/hard-to-reach in countries contained within the European region, and the respective barriers these groups face when participating in clinical studies. Our findings aid with the design of tailored interventions (within-and across-countries of the European region) and with the development of strategies to overcome major barriers in phase 2 and phase 3 vaccine trial participation.

Impact of vaccination and variants of concern on long COVID clinical phenotypes.

BACKGROUND: Defining patterns of symptoms in long COVID is necessary to advance therapies for this heterogeneous condition. Here we aimed to describe clusters of symptoms in individuals with long COVID and explore the impact of the emergence of variants of concern (VOCs) and vaccination on these clusters. METHODS: In a prospective, multi centre cohort study, individuals with symptoms persisting > 4 weeks from acute COVID-19 were divided into two groups based on timing of acute infection; pre-Alpha VOC, denoted wild type (WT) group and post-Alpha VOC (incorporating alpha and delta dominant periods) denoted VOC group. We used multiple correspondence analysis (MCA) and hierarchical clustering in the WT and VOC groups to identify symptom clusters. We then used logistic regression to explore factors associated with individual symptoms. RESULTS: A total of 417 individuals were included in the analysis, 268 in WT and 149 in VOC groups respectively. In both groups MCA identified three similar clusters; a musculoskeletal (MSK) cluster characterised by joint pain and myalgia, a cardiorespiratory cluster and a less symptomatic cluster. Differences in characteristic symptoms were only seen in the cardiorespiratory cluster where a decrease in the frequency of palpitations (10% vs 34% p = 0.008) and an increase in cough (63% vs 17% p < 0.001) in the VOC compared to WT groups was observed. Analysis of the frequency of individual symptoms showed significantly lower frequency of both chest pain (25% vs 39% p = 0.004) and palpitations (12% vs 32% p < 0.001) in the VOC group compared to the WT group. In adjusted analysis being in the VOC group was significantly associated with a lower odds of both chest pain and palpitations, but vaccination was not associated with these symptoms. CONCLUSION: This study suggests changes in long COVID phenotype in individuals infected later in the pandemic, with less palpitations and chest pain reported. Adjusted analyses suggest that these effects are mediated through introduction of variants rather than an effect from vaccination.

Development of a novel medium throughput flow-cytometry based micro-neutralisation test for SARS-CoV-2 with applications in clinical vaccine trials and antibody screening.

Quantifying neutralising capacity of circulating SARS-COV-2 antibodies is critical in evaluating protective humoral immune responses generated post-infection/post-vaccination. Here we describe a novel medium-throughput flow cytometry-based micro-neutralisation test to evaluate Neutralising Antibody (NAb) responses against live SARS-CoV-2 Wild Type and Variants of Concern (VOC) in convalescent/vaccinated populations. Flow Cytometry-Based Micro-Neutralisation Test (Micro-NT) was performed in 96-well plates using clinical isolates WT-B, WT-B.1.177.18 and/or VOCs Beta and Omicron. Plasma samples (All Ireland Infectious Diseases (AIID) Cohort) were serially diluted (8 points, half-log) from 1:20 and pre-incubated with SARS-CoV-2 (1h, 37°C). Virus-plasma mixture were added onto Vero E6 or Vero E6/TMPRSS2 cells for 18h. Percentage infected cells was analysed by automated flow cytometry following trypsinisation, fixation and SARS-CoV-2 Nucleoprotein intracellular staining. Half-maximal Neutralisation Titres (NT50) were determined using non-linear regression. Our assay was compared to Plaque Reduction Neutralisation Test (PRNT) and validated against the First WHO International Standard for anti-SARS-CoV-2 immunoglobulin. Both Micro-NT and PRNT achieved comparable NT50 values. Further validation showed adequate correlation with PRNT using a panel of secondary standards of clinical convalescent and vaccinated plasma samples. We found the assay to be reproducible through measuring both repeatability and intermediate precision. Screening 190 convalescent samples and 11 COVID-19 naive controls (AIID cohort) we demonstrated that Micro-NT has broad dynamic range differentiating NT50s <1/20 to >1/5000. We could also characterise immune-escape VOC Beta and Omicron BA.5, achieving fold-reductions in neutralising capacity similar to those published. Our flow cytometry-based Micro-NT is a robust and reliable assay to quantify NAb titres, and has been selected as an endpoint in clinical trials.

Distinct receptor binding domain IgG thresholds predict protective host immunity across SARS-CoV-2 variants and time.

SARS-CoV-2 neutralising antibodies provide protection against COVID-19. Evidence from early vaccine trials suggested binding antibody thresholds could serve as surrogate markers of neutralising capacity, but whether these thresholds predict sufficient neutralising capacity against variants of concern (VOCs), and whether this is impacted by vaccine or infection history remains unclear. Here we analyse individuals recovered from, vaccinated or with hybrid immunity against SARS-CoV-2. An NT50 ≥ 100 IU confers protection in vaccine trials, however, as VOC induce a reduction in NT50, we use NT50 ≥ 1000 IU as a cut off for WT NT50 that would retain neutralisation against VOC. In unvaccinated convalescent participants, a receptor binding domain (RBD) IgG of 456 BAU/mL predicts an NT50 against WT of 1000 IU with an accuracy of 80% (95%CI 73-86%). This threshold maintains accuracy in determining loss of protective immunity against VOC in two vaccinated cohorts. It predicts an NT50 < 100 IU against Beta with an accuracy of 80% (95%CI 67-89%) in 2 vaccine dose recipients. In booster vaccine recipients with a history of COVID-19 (hybrid immunity), accuracy is 87% (95%CI 77-94%) in determining an NT50 of <100 IU against BA.5. This analysis provides a discrete threshold that could be used in future clinical studies.

Anticholinergic medications associated with falls and frailty in people with HIV.

BACKGROUND: Anticholinergic medications (ACMs) are associated with poorer age-related outcomes, including falls and frailty. We investigate associations between ACM use and recurrent falls and frailty among older (aged ≥50 years) people with HIV in the POPPY study. METHODS: Anticholinergic potential of co-medications at study entry was coded using the anticholinergic burden score, anticholinergic risk score, and Scottish Intercollegiate Guidelines Network score; drugs scoring ≥1 on any scale were defined as ACM. Associations with recurrent falls (two or more falls in the previous 28 days) and frailty (modified Fried's) were assessed using logistic regression adjusting for (1) possible demographic/lifestyle confounders and (2) clinical factors and depressive symptoms (Patient Health Questionnaire-9). RESULTS: ACM use was reported by 193 (28%) of 699 participants, with 64 (9%) receiving two or more ACM; commonly prescribed ACMs were codeine (12%), citalopram (12%), loperamide (9%), and amitriptyline (7%). Falls were reported in 63/673 (9%), and 126/609 (21%) met the frailty criteria. Both recurrent falls and frailty were more common in ACM users than in non-users (recurrent falls: 17% in users vs. 6% in non-users, p < 0.001; frailty: 32% vs. 17%, respectively, p < 0.001). Use of two or more ACMs was associated with increased odds of falls after adjustment for demographic/lifestyle factors (odds ratio [OR] 4.53; 95% confidence interval [CI] 2.06-9.98) and for clinical factors (OR 3.58; 95% CI 1.37-9.38). Similar albeit weaker associations were seen with frailty (OR 2.26; 95% CI 1.09-4.70 and OR 2.12; 95% CI 0.89-5.0, respectively). CONCLUSIONS: ACM are commonly prescribed for people living with HIV, and evidence exists for an association with recurrent falls and frailty. Clinicians should be alert to this and reduce ACM exposure where possible.

Dysregulated early transcriptional signatures linked to mast cell and interferon responses are implicated in COVID-19 severity.

Background: Dysregulated immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are thought to underlie the progression of coronavirus disease 2019 (COVID-19) to severe disease. We sought to determine whether early host immune-related gene expression could predict clinical progression to severe disease. Methods: We analysed the expression of 579 immunological genes in peripheral blood mononuclear cells taken early after symptom onset using the NanoString nCounter and compared SARS-CoV-2 negative controls with SARS-CoV-2 positive subjects with mild (SARS+ Mild) and Moderate/Severe disease to evaluate disease outcomes. Biobanked plasma samples were also assessed for type I (IFN-α2a and IFN-ß), type II (IFN-γ) and type III (IFN-λ1) interferons (IFNs) as well as 10 additional cytokines using multiplex immunoassays. Results: We identified 19 significantly deregulated genes in 62 SARS-CoV-2 positive subject samples within 5 days of symptom onset and 58 SARS-CoV-2 negative controls and found that type I interferon (IFN) signalling (MX1, IRF7, IFITM1, IFI35, STAT2, IRF4, PML, BST2, STAT1) and genes encoding proinflammatory cytokines (TNF, TNFSF4, PTGS2 and IL1B) were upregulated in both SARS+ groups. Moreover, we found that FCER1, involved in mast cell activation, was upregulated in the SARS+ Mild group but significantly downregulated in the SARS+ Moderate/Severe group. In both SARS+ groups we discovered elevated interferon type I IFN-α2a, type II IFN and type III IFN λ1 plasma levels together with higher IL-10 and IL-6. These results indicate that those with moderate or severe disease are characterised by deficiencies in a mast cell response together with IFN hyper-responsiveness, suggesting that early host antiviral immune responses could be a cause and not a consequence of severe COVID-19. Conclusions: This study suggests that early host immune responses linking defects in mast cell activation with host interferon responses correlates with more severe outcomes in COVID-19. Further characterisation of this pathway could help inform better treatment for vulnerable individuals.

Long COVID: Clinical characteristics, proposed pathogenesis and potential therapeutic targets.

The emergence of persistent ill-health in the aftermath of SARS-CoV-2 infection has presented significant challenges to patients, healthcare workers and researchers. Termed long COVID, or post-acute sequelae of COVID-19 (PASC), the symptoms of this condition are highly variable and span multiple body systems. The underlying pathophysiology remains poorly understood, with no therapeutic agents proven to be effective. This narrative review describes predominant clinical features and phenotypes of long COVID alongside the data supporting potential pathogenesis of these phenotypes including ongoing immune dysregulation, viral persistence, endotheliopathy, gastrointestinal microbiome disturbance, autoimmunity, and dysautonomia. Finally, we describe current potential therapies under investigation, as well as future potential therapeutic options based on the proposed pathogenesis research.

A novel antiviral formulation containing caprylic acid inhibits SARS-CoV-2 infection of a human bronchial epithelial cell model.

A novel proprietary formulation, ViruSAL, has previously been demonstrated to inhibit diverse enveloped viral infections in vitro and in vivo. We evaluated the ability of ViruSAL to inhibit SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) infectivity, using physiologically relevant models of the human bronchial epithelium, to model early infection of the upper respiratory tract. ViruSAL potently inhibited SARS-CoV-2 infection of human bronchial epithelial cells cultured as an air-liquid interface (ALI) model, in a concentration- and time-dependent manner. Viral infection was completely inhibited when ViruSAL was added to bronchial airway models prior to infection. Importantly, ViruSAL also inhibited viral infection when added to ALI models post-infection. No evidence of cellular toxicity was detected in ViruSAL-treated cells at concentrations that completely abrogated viral infectivity. Moreover, intranasal instillation of ViruSAL to a rat model did not result in any toxicity or pathological changes. Together these findings highlight the potential for ViruSAL as a novel and potent antiviral for use within clinical and prophylactic settings.

Endothelial cell activation, Weibel-Palade body secretion, and enhanced angiogenesis in severe COVID-19.

Background: Severe COVID-19 is associated with marked endothelial cell (EC) activation that plays a key role in immunothrombosis and pulmonary microvascular occlusion. However, the biological mechanisms through which SARS-CoV-2 causes EC activation and damage remain poorly defined. Objectives: We investigated EC activation in patients with acute COVID-19, and specifically focused on how proteins stored within Weibel-Palade bodies may impact key aspects of disease pathogenesis. Methods: Thirty-nine patients with confirmed COVID-19 were recruited. Weibel-Palade body biomarkers (von Willebrand factor [VWF], angiopoietin-2 [Angpt-2], and osteoprotegerin) and soluble thrombomodulin (sTM) levels were determined. In addition, EC activation and angiogenesis were assessed in the presence or absence of COVID-19 plasma incubation. Results: Markedly elevated plasma VWF antigen, Angpt-2, osteoprotegerin, and sTM levels were observed in patients with acute COVID-19. The increased levels of both sTM and Weibel-Palade body components (VWF, osteoprotegerin, and Angpt-2) correlated with COVID-19 severity. Incubation of COVID-19 plasma with ECs triggered enhanced VWF secretion and increased Angpt-2 expression, as well as significantly enhanced in vitro EC tube formation and angiogenesis. Conclusion: We propose that acute SARS-CoV-2 infection leads to a complex and multifactorial EC activation, progressive loss of thrombomodulin, and increased Angpt-2 expression, which collectively serve to promote a local proangiogenic state.

HIV and comorbidities - the importance of gut inflammation and the kynurenine pathway.

PURPOSE OF REVIEW: The purpose of this article is to review alterations in microbiota composition, diversity, and functional features in the context of chronic inflammation and comorbidities associated with HIV infection. RECENT FINDINGS: The gut microbiome is an important mediator of host immunity, and disruption of gut homeostasis can contribute to both systemic inflammation and immune activation. Ageing and HIV share features of intestinal damage, microbial translocation and alterations in bacterial composition that contribute to a proinflammatory state and development of age-related comorbidities. One such inflammatory pathway reviewed is the nicotinamide adenine dinucleotide (NAD+) producing kynurenine pathway (KP). Kynurenine metabolites regulate many biological processes including host-microbiome communication, immunity and oxidative stress and the KP in turn is influenced by the microbiome environment. Age-associated decline in NAD+ is implicated as a driving factor in many age-associated diseases, including those seen in people with HIV (PWH). Recent studies have shown that KP can influence metabolic changes in PWH, including increased abdominal adiposity and cardiovascular disease. Furthermore, KP activity increases with age in the general population, but it is elevated in PWH at all ages compared to age-matched controls. Host or microbiome-mediated targeting of this pathway has merits to increase healthy longevity and has potential therapeutic applications in PWH. SUMMARY: As a growing proportion of PWH age, many face increased risks of developing age-related comorbidities. Chronic inflammation, a pillar of geroscience, the science of ageing and of age-related disease, is influenced by the gut microbiome and its metabolites. Combined, these contribute to a systemic inflammatory signature. Advances in geroscience-based approaches and therapeutics offer a novel paradigm for addressing age-related diseases and chronic inflammation in HIV infection. Whether targeted inhibition of KP activity alleviates pathological conditions or promotes successful ageing in PWH remains to be determined.

Prediction of low pulse oxygen saturation in COVID-19 using remote monitoring post hospital discharge.

BACKGROUND: Monitoring systems have been developed during the COVID-19 pandemic enabling clinicians to remotely monitor physiological measures including pulse oxygen saturation (SpO2), heart rate (HR), and breathlessness in patients after discharge from hospital. These data may be leveraged to understand how symptoms vary over time in COVID-19 patients. There is also potential to use remote monitoring systems to predict clinical deterioration allowing early identification of patients in need of intervention. METHODS: A remote monitoring system was used to monitor 209 patients diagnosed with COVID-19 in the period following hospital discharge. This system consisted of a patient-facing app paired with a Bluetooth-enabled pulse oximeter (measuring SpO2 and HR) linked to a secure portal where data were available for clinical review. Breathlessness score was entered manually to the app. Clinical teams were alerted automatically when SpO2 < 94 %. In this study, data recorded during the initial ten days of monitoring were retrospectively examined, and a random forest model was developed to predict SpO2 < 94 % on a given day using SpO2 and HR data from the two previous days and day of discharge. RESULTS: Over the 10-day monitoring period, mean SpO2 and HR increased significantly, while breathlessness decreased. The coefficient of variation in SpO2, HR and breathlessness also decreased over the monitoring period. The model predicted SpO2 alerts (SpO2 < 94 %) with a mean cross-validated. sensitivity of 66 ± 18.57 %, specificity of 88.31 ± 10.97 % and area under the receiver operating characteristic of 0.80 ± 0.11. Patient age and sex were not significantly associated with the occurrence of asymptomatic SpO2 alerts. CONCLUSION: Results indicate that SpO2 alerts (SpO2 < 94 %) on a given day can be predicted using SpO2 and heart rate data captured on the two preceding days via remote monitoring. The methods presented may help early identification of patients with COVID-19 at risk of clinical deterioration using remote monitoring.

Antigen specific T cells in people with obesity at five months following ChAdOx1 COVID-19 vaccination.

BACKGROUND/OBJECTIVES: People with obesity (PWO) face an increased risk of severe outcomes from COVID-19, including hospitalisation, ICU admission and death. Obesity has been seen to impair immune memory following vaccination against influenza, hepatitis B, tetanus, and rabies. Little is known regarding immune memory in PWO following COVID-19 adenovirus vector vaccination. SUBJECTS/METHODS: We investigated SARS-CoV-2 specific T cell responses in 50 subjects, five months following a two-dose primary course of ChAdOx1 nCoV-19 (AZD1222) vaccination. We further divided our cohort into PWO (n = 30) and matched controls (n = 20). T cell (CD4+, CD8+) cytokine responses (IFNγ, TNFα) to SARS-CoV-2 spike peptide pools were determined using multicolour flow cytometry. RESULTS: Circulating T cells specific for SARS-CoV-2 were readily detected across our cohort, with robust responses to spike peptide stimulation across both T cell lines. PWO and controls had comparable levels of both CD4+ and CD8+ SARS-CoV-2 spike specific T cells. Polyfunctional T cells - associated with enhanced protection against viral infection - were detected at similar frequencies in both PWO and controls. CONCLUSIONS: These data indicate that PWO who have completed a primary course of ChAdOx1 COVID-19 vaccination have robust, durable, and functional antigen specific T cell immunity that is comparable to that seen in people without obesity.

Association between inflammatory biomarker profiles and cardiovascular risk in individuals with and without HIV.

BACKGROUND: People with HIV have an increased risk for cardiovascular morbidity and mortality. Inflammation and immune activation may contribute to this excess risk. METHODS: We assessed thirty-one biomarkers in a subset of POPPY participants and identified three distinct inflammatory profiles: 'gut/immune activation', 'neurovascular', and 'reference' (relatively low levels of inflammation). Ten-year cardiovascular disease (CVD) risk predictions were calculated using the QRISK, Framingham Risk Score (FRS) and the Data Collection on Adverse effects of anti-HIV Drugs (D:A:D) algorithms. The distributions of CVD risk scores across the different inflammatory profiles, stratified by HIV status, were compared using median quantile regression. RESULTS: Of the 312 participants included [70% living with HIV, median (interquartile range; IQR) age 55 (51-60) years; 82% male; 91% white], 36, 130, and 146 were in the 'gut/immune activation', 'neurovascular', and 'reference' cluster, respectively. The median (IQR) QRISK scores were 9.3% (4.5-14.5) and 10.2% (5.5-16.9) for people with and without HV, respectively, with similar scores obtained with the FRS and D:A:D. We observed statistically significant differences between the distributions of scores in the three clusters among people with HV. In particular, median QRISK [5.8% (1.0-10.7) and 3.1% (0.3-5.8)] scores were higher, respectively, for those in the 'gut/immune activation' and 'neurovascular' clusters compared to those in the reference cluster. CONCLUSIONS: People with HIV with increased gut/immune activation have a higher CVD risk compared to those with relatively low inflammation. Our findings highlight that clinically important inflammatory subgroups could be useful to differentiate risk and maximise prediction of CVD among people with HIV.

Performance and validation of an adaptable multiplex assay for detection of serologic response to SARS-CoV-2 infection or vaccination.

Measurement of quantitative antibody responses are increasingly important in evaluating the immune response to infection and vaccination. In this study we describe the validation of a quantitative, multiplex serologic assay utilising an electrochemiluminescence platform, which measures IgG against the receptor binding domain (RBD), spike S1 and S2 subunits and nucleocapsid antigens of SARS-CoV-2. The assay displayed a sensitivity ranging from 73 to 91% and specificity from 90 to 96% in detecting previous infection with SARS-CoV-2 depending on antigenic target and time since infection, and this assay highly correlated with commercially available assays. The within-plate coefficient of variation ranged from 3.8-3.9% and the inter-plate coefficient of variation from 11 to 13% for each antigen.

Biomarker associations with insomnia and secondary sleep outcomes in persons with and without HIV in the POPPY-Sleep substudy: a cohort study.

STUDY OBJECTIVES: We investigated associations between inflammatory profiles/clusters and sleep measures in people living with HIV and demographically-/lifestyle-similar HIV-negative controls in the Pharmacokinetic and clinical Observations in PeoPle over fiftY (POPPY)-Sleep substudy. METHODS: Primary outcome was insomnia (Insomnia Severity Index [ISI]>15). Secondary sleep outcomes included 7-day actigraphy (e.g. mean/standard deviation of sleep duration/efficiency), overnight oximetry (e.g. oxygen desaturation index [ODI]) and patient-reported measures (Patient-Reported Outcomes Measurement Information System (PROMIS) sleep questionnaires). Participants were grouped using Principal Component Analysis of 31 biomarkers across several inflammatory pathways followed by cluster analysis. Between-cluster differences in baseline characteristics and sleep outcomes were assessed using Kruskal-Wallis/logistic regression/Chi-squared/Fisher's exact tests. RESULTS: Of the 465 participants included (74% people with HIV, median [interquartile range] age 54 [50-60] years), only 18% had insomnia and secondary sleep outcomes suggested generally good sleep (e.g. ODI 3.1/hr [1.5-6.4]). Three clusters with distinct inflammatory profiles were identified: "gut/immune activation" (n = 47), "neurovascular" (n = 209), and "reference" (relatively lower inflammation; n = 209). The "neurovascular" cluster included higher proportions of people with HIV, obesity (BMI>30 kg/m2), and previous cardiovascular disease, mental health disorder, and arthritis of knee/hip relative to the other two clusters. No clinically relevant between-cluster differences were observed in proportions with insomnia (17%, 18%, 20%) before (p = .76) or after (p = .75) adjustment for potential confounders. Few associations were observed among actigraphy, oximetry, and PROMIS measures. CONCLUSIONS: Although associations could exist with other sleep measures or biomarker types not assessed, our findings do not support a strong association between sleep and inflammation in people with HIV.

Obesity in HIV infection: host-pathogen interaction.

OBJECTIVE: Both obesity and HIV infection are characterized by a state of chronic inflammation associated with increased morbidity and mortality. This review aims to assess the available literature on immune dysregulation in obesity and people with HIV infection (PWH). DESIGN: A systematic review of peer-reviewed literature. METHODS: We conducted a systematic literature search of PubMed, Embase, Scopus, and international conference abstracts for articles on the epidemiology of obesity in the general population and in PWH and the pathogenesis of obesity with a focus on inflammation and immune activation. RESULTS: Of the 631 articles selected after title review, 490 met the inclusion criteria and 90 were included in the final selection. The selected studies highlight the increasing prevalence of obesity in PWH and a substantial role for antiretroviral treatment (ART) in its development. Pathogenesis of obesity and its associated inflammation derives from disturbances in adipose tissue (AT) immune function, focused on T-cell and macrophage function, with a switch to pro-inflammatory immune phenotype and resulting increases in pro-inflammatory chemokines, which contribute to the development of metabolic syndrome. Although dysregulation of these pathways is seen in both obesity and HIV, there remains a lack of human studies on AT inflammation in HIV. CONCLUSION: Obesity is an emerging comorbidity in PWH, with a substantial overlap in immune dysregulation patterns seen in both conditions. How this immune dysfunction impacts on development of metabolic complications for both obesity and HIV infection, and whether targeting of AT-derived inflammation will improve outcomes in PWH requires further study.