A Dengue Vaccine.

Denvaxia is the first licensed vaccine for the prevention of dengue. It is a live vaccine developed using recombinant DNA technology. The vaccine is given as three doses over the course of a year and has the potential to prevent hundreds of thousands of hospitalizations each year.

Phase 3 Safety and Efficacy of AZD1222 (ChAdOx1 nCoV-19) Covid-19 Vaccine.

BACKGROUND: The safety and efficacy of the AZD1222 (ChAdOx1 nCoV-19) vaccine in a large, diverse population at increased risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the United States, Chile, and Peru has not been known. METHODS: In this ongoing, double-blind, randomized, placebo-controlled, phase 3 clinical trial, we investigated the safety, vaccine efficacy, and immunogenicity of two doses of AZD1222 as compared with placebo in preventing the onset of symptomatic and severe coronavirus disease 2019 (Covid-19) 15 days or more after the second dose in adults, including older adults, in the United States, Chile, and Peru. RESULTS: A total of 32,451 participants underwent randomization, in a 2:1 ratio, to receive AZD1222 (21,635 participants) or placebo (10,816 participants). AZD1222 was safe, with low incidences of serious and medically attended adverse events and adverse events of special interest; the incidences were similar to those observed in the placebo group. Solicited local and systemic reactions were generally mild or moderate in both groups. Overall estimated vaccine efficacy was 74.0% (95% confidence interval [CI], 65.3 to 80.5; P<0.001) and estimated vaccine efficacy was 83.5% (95% CI, 54.2 to 94.1) in participants 65 years of age or older. High vaccine efficacy was consistent across a range of demographic subgroups. In the fully vaccinated analysis subgroup, no severe or critical symptomatic Covid-19 cases were observed among the 17,662 participants in the AZD1222 group; 8 cases were noted among the 8550 participants in the placebo group (<0.1%). The estimated vaccine efficacy for preventing SARS-CoV-2 infection (nucleocapsid antibody seroconversion) was 64.3% (95% CI, 56.1 to 71.0; P<0.001). SARS-CoV-2 spike protein binding and neutralizing antibodies increased after the first dose and increased further when measured 28 days after the second dose. CONCLUSIONS: AZD1222 was safe and efficacious in preventing symptomatic and severe Covid-19 across diverse populations that included older adults. (Funded by AstraZeneca and others; ClinicalTrials.gov number, NCT04516746.).

Fourth Controlled Human Infection Model (CHIM) meeting, CHIM regulatory issues, May 24, 2023.

Many aspects of Controlled Human Infection Models (CHIMs, also known as human challenge studies and human infection studies) have been discussed extensively, including Good Manufacturing Practice (GMP) production of the challenge agent, CHIM ethics, environmental safety in CHIM, recruitment, community engagement, advertising and incentives, pre-existing immunity, and clinical, immunological, and microbiological endpoints. The fourth CHIM meeting focused on regulation of CHIM studies, bringing together scientists and regulators from high-, middle-, and low-income countries, to discuss barriers and hurdles in CHIM regulation. Valuable initiatives for regulation of CHIMs have already been undertaken but further capacity building remains essential. The Wellcome Considerations document is a good starting point for further discussions.

Fourth Controlled Human Infection Model (CHIM) meeting - CHIMs in endemic countries, May 22-23, 2023.

Earlier meetings laid the foundations for Controlled Human Infection Models (CHIMs), also known as human challenge studies and human infection studies, including Good Manufacturing Practice (GMP) production of the challenge agent, CHIM ethics, environmental safety in CHIM, recruitment, community engagement, advertising and incentives, pre-existing immunity, and clinical, immunological, and microbiological endpoints. The fourth CHIM meeting focused on CHIM studies being conducted in endemic countries. Over the last ten years we have seen a vast expansion of the number of countries in Africa performing CHIM studies, as well as a growing number of different challenge organisms being used. Community and public engagement with assiduous ethical and regulatory oversight has been central to successful introductions and should be continued, in more community-led or community-driven models. Valuable initiatives for regulation of CHIMs have been undertaken but further capacity building remains essential.

Intellectual and developmental disabilities in Ontario's criminal justice and forensic mental health systems: Using data to tell the story.

BACKGROUND: International studies show that adults with intellectual and developmental disabilities (IDD) are disproportionately represented in the criminal justice and forensic mental health systems; however, it is difficult to capture their involvement across systems in any one jurisdiction. AIMS: The current study aimed to estimate the prevalence of IDD across different parts of the criminal justice and forensic mental health systems in Ontario and to describe the demographic and clinical profiles of these individuals relative to their counterparts without IDD. METHODS: This project utilised administrative data to identify and describe the demographic and clinical characteristics of adults with IDD and criminal justice or forensic involvement across four sectors: federal correctional facilities, provincial correctional facilities, forensic inpatient mental health care and community mental health programmes. Questions were driven by and results were contextualised by a project advisory group and people with lived experience from the different sectors studied, resulting in a series of recommendations. RESULTS: Adults with IDD were over-represented in each of the four settings, ranging from 2.1% in federal corrections to 16.7% in forensic inpatient care. Between 20% (forensic inpatient) and 38.4% (provincial corrections) were under the age of 25 and between 34.5% (forensic inpatient) and 41.8% (provincial corrections) resided in the lowest income neighbourhoods. Medical complexity and rates of co-occurring mental health conditions were higher for people with IDD than those without IDD in federal and provincial corrections. CONCLUSIONS: Establishing a population-based understanding of people with IDD within these sectors is an essential first step towards understanding and addressing service and care needs. Building on the perspectives of people who work in and use these systems, this paper concludes with intervention recommendations before, during and after justice involvement.

Phase 1 trial to model primary, secondary, and tertiary dengue using a monovalent vaccine.

BACKGROUND: The four co-circulating and immunologically interactive dengue virus serotypes (DENV1-4) pose a unique challenge to vaccine design because sub-protective immunity can increase the risk of severe dengue disease. Existing dengue vaccines have lower efficacy in DENV seronegative individuals but higher efficacy in DENV exposed individuals. There is an urgent need to identify immunological measures that are strongly associated with protection against viral replication and disease following sequential exposure to distinct serotypes. METHODS/DESIGN: This is a phase 1 trial wherein healthy adults with neutralizing antibodies to zero (seronegative), one non-DENV3 (heterotypic), or more than one (polytypic) DENV serotype will be vaccinated with the live attenuated DENV3 monovalent vaccine rDEN3Δ30/31-7164. We will examine how pre-vaccine host immunity influences the safety and immunogenicity of DENV3 vaccination in a non-endemic population. We hypothesize that the vaccine will be safe and well tolerated, and all groups will have a significant increase in the DENV1-4 neutralizing antibody geometric mean titer between days 0 and 28. Compared to the seronegative group, the polytypic group will have lower mean peak vaccine viremia, due to protection conferred by prior DENV exposure, while the heterotypic group will have higher mean peak viremia, due to mild enhancement. Secondary and exploratory endpoints include characterizing serological, innate, and adaptive cell responses; evaluating proviral or antiviral contributions of DENV-infected cells; and immunologically profiling the transcriptome, surface proteins, and B and T cell receptor sequences and affinities of single cells in both peripheral blood and draining lymph nodes sampled via serial image-guided fine needle aspiration. DISCUSSION: This trial will compare the immune responses after primary, secondary, and tertiary DENV exposure in naturally infected humans living in non-endemic areas. By evaluating dengue vaccines in a new population and modeling the induction of cross-serotypic immunity, this work may inform vaccine evaluation and broaden potential target populations. TRIAL REGISTRATION: NCT05691530 registered on January 20, 2023.

Amenable deaths among adults with intellectual and developmental disabilities including Down syndrome: An Ontario population-based cohort study.

BACKGROUND: Rates of death and avoidable deaths are reportedly higher among people with intellectual and developmental disabilities. This study contributes to our understanding of how mortality and intellectual and development disabilities are associated. METHOD: General population and intellectual and developmental disabilities adult cohorts were defined using linked administrative data. All-cause and amenable deaths between 2010 and 2015 were reported for these cohorts and subcohorts with and without Down syndrome. Cox proportional hazards models evaluated the impact of potential contributors to amenable deaths. RESULTS: Adults with intellectual and developmental disabilities had higher all-cause (6.1 vs. 1.6%) and amenable death percentages (21.4 vs. 14.1%) than general population comparators. Within intellectual and developmental disabilities, those with Down syndrome had higher all-cause (12.0 vs. 6.0%) but lower amenable death percentages (19.2 vs. 21.8%) than those without. CONCLUSIONS: Results suggest that interventions to reduce amenable deaths target provider-care-recipient interactions and coordination across care and support sectors.

Dengue Virus Serotype 1 Conformational Dynamics Confers Virus Strain-Dependent Patterns of Neutralization by Polyclonal Sera.

Dengue virus cocirculates globally as four serotypes (DENV1 to -4) that vary up to 40% at the amino acid level. Viral strains within a serotype further cluster into multiple genotypes. Eliciting a protective tetravalent neutralizing antibody response is a major goal of vaccine design, and efforts to characterize epitopes targeted by polyclonal mixtures of antibodies are ongoing. Previously, we identified two E protein residues (126 and 157) that defined the serotype-specific antibody response to DENV1 genotype 4 strain West Pac-74. DENV1 and DENV2 human vaccine sera neutralized DENV1 viruses incorporating these substitutions equivalently. In this study, we explored the contribution of these residues to the neutralization of DENV1 strains representing distinct genotypes. While neutralization of the genotype 1 strain TVP2130 was similarly impacted by mutation at E residues 126 and 157, mutation of these residues in the genotype 2 strain 16007 did not markedly change neutralization sensitivity, indicating the existence of additional DENV1 type-specific antibody targets. The accessibility of antibody epitopes can be strongly influenced by the conformational dynamics of virions and modified allosterically by amino acid variation. We found that changes at E domain II residue 204, shown previously to impact access to a poorly accessible E domain III epitope, impacted sensitivity of DENV1 16007 to neutralization by vaccine immune sera. Our data identify a role for minor sequence variation in changes to the antigenic structure that impacts antibody recognition by polyclonal immune sera. Understanding how the many structures sampled by flaviviruses influence antibody recognition will inform the design and evaluation of DENV immunogens. IMPORTANCE Dengue virus (DENV) is an important human pathogen that cocirculates globally as four serotypes. Because sequential infection by different DENV serotypes is associated with more severe disease, eliciting a protective neutralizing antibody response against all four serotypes is a major goal of vaccine efforts. Here, we report that neutralization of DENV serotype 1 by polyclonal antibody is impacted by minor sequence variation among virus strains. Our data suggest that mechanisms that control neutralization sensitivity extend beyond variation within antibody epitopes but also include the influence of single amino acids on the ensemble of structural states sampled by structurally dynamic virions. A more detailed understanding of the antibody targets of DENV-specific polyclonal sera and factors that govern their access to antibody has important implications for flavivirus antigen design and evaluation.

'More together than apart': The evaluation of a virtual course to improve mental health and well-being of adults with intellectual disabilities during the COVID-19 pandemic.

BACKGROUND: To address the growing concerns over poor mental health experienced by adults with intellectual disabilities due to the COVID-19 pandemic, a national virtual mental health course was delivered and evaluated. METHODS: This mixed methods study utilized both qualitative and quantitative assessments. Participants were 27 adults with intellectual disabilities who participated in the 6-week course. Participants completed measures of self-efficacy and well-being at three time points and qualitative satisfaction measures at post and follow-up. RESULTS: Attendance was high and the course was feasible and acceptable to participants. Positive changes related to mental health self-efficacy were detected (p = .01), though mental well-being did not improve. CONCLUSION: The study provided evidence for the feasibility and value of the course for this population. Future research should examine how virtual courses could support the population in terms of pandemic recovery and how courses may work for individuals who are less independent.

Intellectual/developmental disabilities among people incarcerated in federal correctional facilities in Ontario, Canada: Examining prevalence, health and correctional characteristics.

BACKGROUND: There is little research with people who experience intellectual/developmental disabilities and imprisonment. METHODS: The study linked health and correctional data to examine prevalence of intellectual/developmental disabilities and health and correctional characteristics among adults experiencing their first federal incarceration between 1 January 2002 and 31 December 2011 (n = 9278) and two non-incarcerated groups (n = 10,086,802). RESULTS: The prevalence of intellectual/developmental disabilities was 2.1% in the incarcerated group and 0.9% in the non-incarcerated group. Before incarceration, those with, versus without, intellectual/developmental disabilities were at greater risk of traumatic brain injury, mental illness, and substance use disorders. While incarcerated, those with intellectual/developmental disabilities were more likely to incur serious institutional disciplinary charges. Post-incarceration, persons with intellectual/developmental disabilities were at greater risk of emergency department visits, and psychiatric and acute hospitalizations, than the non-incarcerated groups. CONCLUSIONS: People with intellectual/developmental disabilities are overrepresented in Canadian federal correctional institutions. The authors offer strategies to support people prior to, during, and post-incarceration.

Viewpoint of a WHO Advisory Group Tasked to Consider Establishing a Closely-monitored Challenge Model of Coronavirus Disease 2019 (COVID-19) in Healthy Volunteers.

WHO convened an Advisory Group (AG) to consider the feasibility, potential value, and limitations of establishing a closely-monitored challenge model of experimental severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) in healthy adult volunteers. The AG included experts in design, establishment, and performance of challenges. This report summarizes issues that render a COVID-19 model daunting to establish (the potential of SARS-CoV-2 to cause severe/fatal illness, its high transmissibility, and lack of a "rescue treatment" to prevent progression from mild/moderate to severe clinical illness) and it proffers prudent strategies for stepwise model development, challenge virus selection, guidelines for manufacturing challenge doses, and ways to contain SARS-CoV-2 and prevent transmission to household/community contacts. A COVID-19 model could demonstrate protection against virus shedding and/or illness induced by prior SARS-CoV-2 challenge or vaccination. A limitation of the model is that vaccine efficacy in experimentally challenged healthy young adults cannot per se be extrapolated to predict efficacy in elderly/high-risk adults.

T Cell Responses Induced by Attenuated Flavivirus Vaccination Are Specific and Show Limited Cross-Reactivity with Other Flavivirus Species.

Members of the flavivirus genus share a high level of sequence similarity and often circulate in the same geographical regions. However, whether T cells induced by one viral species cross-react with other related flaviviruses has not been globally addressed. In this study, we tested pools of epitopes derived from dengue (DENV), Zika (ZIKV), Japanese encephalitis (JEV), West Nile (WNV), and yellow fever (YFV) viruses by intracellular cytokine staining (ICS) using peripheral blood mononuclear cells (PBMCs) of individuals naturally exposed to DENV or immunized with DENV (TV005) or YF17D vaccine. CD8 T cell responses recognized epitopes from multiple flaviviruses; however, the magnitude of cross-reactive responses was consistently severalfold lower than those to the autologous epitope pools and was associated with lower expression of activation markers such as CD40L, CD69, and CD137. Next, we characterized the antigen sensitivity of short-term T cell lines (TCL) representing 29 different individual epitope/donor combinations. TCL derived from DENV monovalent vaccinees induced CD8 and CD4 T cells that cross-reacted within the DENV serocomplex but were consistently associated with >100-fold-lower antigen sensitivity for most other flaviviruses, with no cross-recognition of YFV-derived peptides. CD8 and CD4 TCL from YF17D vaccinees were associated with very limited cross-reactivity with any other flaviviruses and in five out of eight cases >1,000-fold-lower antigen sensitivity. Overall, our data suggest limited cross-reactivity for both CD4 and CD8 T cell responses between flaviviruses and have implications for understanding immunity elicited by natural infection and strategies to develop live attenuated vaccines against flaviviral species.IMPORTANCE The envelope (E) protein is the dominant target of neutralizing antibodies for dengue virus (DENV) and yellow fever virus (YFV). Accordingly, several DENV vaccine constructs use the E protein in a live attenuated vaccine format, utilizing a backbone derived from a heterologous flavivirus (such as YF) as a delivery vector. This backbone comprises the nonstructural (NS) and capsid (C) antigens, which are dominant targets of T cell responses. Here, we demonstrate that cross-reactivity at the level of T cell responses among different flaviviruses is very limited, despite high levels of sequence homology. Thus, the use of heterologous flavivirus species as a live attenuated vaccine vector is not likely to generate optimal T cell responses and might thus impair vaccine performance.

Looking across health and healthcare outcomes for people with intellectual and developmental disabilities and psychiatric disorders: population-based longitudinal study.

BACKGROUND: Intellectual and developmental disabilities (IDDs) and psychiatric disorders frequently co-occur. Although each has been associated with negative outcomes, their combined effect has rarely been studied. AIMS: To examine the likelihood of five negative health and healthcare outcomes for adults with IDD and mental health/addiction disorders (MHAs), both separately and together. For each outcome, demographic, clinical and system-level factors were also examined. METHOD: Linked administrative data-sets were used to identify adults in Ontario, Canada, with IDD and MHA (n = 29 476), IDD-only (n = 35 223) and MHA-only (n = 727 591). Five outcomes (30-day readmission, 30-day repeat ED visit, delayed discharge, long-term care admission and premature mortality) were examined by logistic regression models with generalised estimating equation or survival analyses. For each outcome, crude (disorder groups only) and complete (adding biosocial covariates) models were run using a general population reference group. RESULTS: The IDD and MHA group had the highest proportions across outcomes for both crude and complete models. They had the highest adjusted ratios for readmissions (aOR 1.93, 95%CI 1.88-1.99), repeat ED visit (aOR 2.00, 95%CI 1.98-2.02) and long-term care admission (aHR 12.19, 95%CI 10.84-13.71). For delayed discharge, the IDD and MHA and IDD-only groups had similar results (aOR 2.00 (95%CI 1.90-2.11) and 2.21 (95%CI 2.07-2.36). For premature mortality, the adjusted ratios were similar for all groups. CONCLUSIONS: Poorer outcomes for adults with IDD, particularly those with MHA, suggest a need for a comprehensive, system-wide approach spanning health, disability and social support.

The Effect of a Housing First Intervention on Acute Health Care Utilization among Homeless Adults with Mental Illness: Long-term Outcomes of the At Home/Chez-Soi Randomized Pragmatic Trial.

We assessed the effects of the Toronto Site Housing First (HF) intervention on hospitalizations and emergency department (ED) visits among homeless adults with mental illness over 7 years of follow-up. The Toronto Site is part of an unblinded multi-site randomized pragmatic trial of HF for homeless adults with mental illness in Canada, which followed participants up to 7 years. Five hundred seventy-five participants were recruited and classified as having high (HN) or moderate need (MN) for mental health support services. Each group was randomized into intervention (HF) and treatment as usual groups, and 567 (98.6%) consented to link their data to health administrative databases. HF participants received a monthly rent supplement of $600 (Canadian) and assertive community treatment (ACT) support or intensive care management (ICM) support based on need level. Treatment as usual (TAU) participants had access to social, housing, and health services generally available in the community. Outcomes included all-cause and mental health-specific hospitalization, number of days in hospital, and ED visit. We used GEE models to estimate ratio of rate ratios (RRR). The results showed HF with ACT had no significant effect on hospitalization rates among HN participants, but reduced the number of days in hospital (RRR = 0.32, 95% CI 0.16-0.63) and number of ED visits (RRR = 0.57, 95% CI 0.34-0.95). HF with ICM resulted in an increase in the number of hospitalizations (RRR = 1.69, 95% CI 1.09-2.60) and ED visit rates (RRR = 1.42, 95% CI 1.01-2.01) but had no effect in days in hospital for MN participants. Addressing the health needs of this population and reducing acute care utilization remain system priorities. Trial registration: http://www.isrctn.com/identifier: ISRCTN42520374.

Associations of resilience with quality of life levels in adults experiencing homelessness and mental illness: a longitudinal study.

BACKGROUND: Homelessness constitutes a traumatic period that adversely impacts health and quality of life outcomes. The potential mitigating effects of resilience on quality of life levels in people experiencing homelessness are underresearched. This study assesses the longitudinal associations between resilience and quality of life scores among adults experiencing homelessness and mental illness. METHODS: This study is a secondary analysis of longitudinal data collected over 6 years from participants (N = 575) of the At Home/Chez Soi study on Housing First, Toronto site. Repeatedly measured resilience scores are the primary exposure and repeatedly measured global quality of life scores and mental health-specific quality of life scores are the primary outcomes. Mixed effect models were used to assess the association between the exposures and the outcomes. RESULTS: The majority of the participants were men (69.2%) and were on average 40.4 (± 11.8) years old at baseline. The average resilience score ranged between 5.00 to 5.62 over 8 data collection points across the 6-year follow-up period. After adjusting for gender, age, ethno-racial background, Housing First intervention, physical and mental comorbidities, and lifetime homelessness, higher resilience scores were positively associated with higher Global quality of life (Adjusted-coefficient: 0.23, 95% CI 0.19-0.27) and mental health-related quality of life values (Adjusted-coefficient: 4.15, 95% CI 3.35-4.95). CONCLUSION: In homeless adults with mental illness, higher resilience levels were positively associated with higher global and mental health related quality of life values. Further interventions and services aimed to enhance resilience mechanisms and strategies are warranted to enhance better mental health and quality of life outcomes of this population group. TRIAL REGISTRATION: At Home/Chez Soi trial was registered with ISRCTN, ISRCTN42520374. Registered 18 September 2009, http://www.isrctn.com/ISRCTN42520374.

US Case Reports of Cerebral Venous Sinus Thrombosis With Thrombocytopenia After Ad26.COV2.S Vaccination, March 2 to April 21, 2021.

Importance: Cerebral venous sinus thrombosis (CVST) with thrombocytopenia, a rare and serious condition, has been described in Europe following receipt of the ChAdOx1 nCoV-19 vaccine (Oxford/AstraZeneca), which uses a chimpanzee adenoviral vector. A mechanism similar to autoimmune heparin-induced thrombocytopenia (HIT) has been proposed. In the US, the Ad26.COV2.S COVID-19 vaccine (Janssen/Johnson & Johnson), which uses a human adenoviral vector, received Emergency Use Authorization (EUA) on February 27, 2021. By April 12, 2021, approximately 7 million Ad26.COV2.S vaccine doses had been given in the US, and 6 cases of CVST with thrombocytopenia had been identified among the recipients, resulting in a temporary national pause in vaccination with this product on April 13, 2021. Objective: To describe reports of CVST with thrombocytopenia following Ad26.COV2.S vaccine receipt. Design, Setting, and Participants: Case series of 12 US patients with CVST and thrombocytopenia following use of Ad26.COV2.S vaccine under EUA reported to the Vaccine Adverse Event Reporting System (VAERS) from March 2 to April 21, 2021 (with follow-up reported through April 21, 2021). Exposures: Receipt of Ad26.COV2.S vaccine. Main Outcomes and Measures: Clinical course, imaging, laboratory tests, and outcomes after CVST diagnosis obtained from VAERS reports, medical record review, and discussion with clinicians. Results: Patients' ages ranged from 18 to younger than 60 years; all were White women, reported from 11 states. Seven patients had at least 1 CVST risk factor, including obesity (n = 6), hypothyroidism (n = 1), and oral contraceptive use (n = 1); none had documented prior heparin exposure. Time from Ad26.COV2.S vaccination to symptom onset ranged from 6 to 15 days. Eleven patients initially presented with headache; 1 patient initially presented with back pain and later developed headache. Of the 12 patients with CVST, 7 also had intracerebral hemorrhage; 8 had non-CVST thromboses. After diagnosis of CVST, 6 patients initially received heparin treatment. Platelet nadir ranged from 9 ×103/µL to 127 ×103/µL. All 11 patients tested for the heparin-platelet factor 4 HIT antibody by enzyme-linked immunosorbent assay (ELISA) screening had positive results. All patients were hospitalized (10 in an intensive care unit [ICU]). As of April 21, 2021, outcomes were death (n = 3), continued ICU care (n = 3), continued non-ICU hospitalization (n = 2), and discharged home (n = 4). Conclusions and Relevance: The initial 12 US cases of CVST with thrombocytopenia after Ad26.COV2.S vaccination represent serious events. This case series may inform clinical guidance as Ad26.COV2.S vaccination resumes in the US as well as investigations into the potential relationship between Ad26.COV2.S vaccine and CVST with thrombocytopenia.

Health and service use of newcomers and other adults with intellectual and developmental disabilities: A population-based study.

BACKGROUND: This study examines newcomers with intellectual and developmental disabilities compared to other adults with intellectual and developmental disabilities in Ontario, Canada. METHODS: This population-based retrospective cohort study used linked health and social services administrative data to identify adults with intellectual and developmental disabilities as newcomers, or non-newcomers, and compared their health status and health service outcomes. RESULTS: Among those with intellectual and developmental disabilities, compared to non-newcomers, newcomers generally had lower or similar rates of health issues, except for higher rates of psychosis. Newcomers also had slightly greater use of community-based health services, but less hospital use. CONCLUSION: Trends among those with the intellectual and developmental disabilities were consistent with general population trends; newcomers had lower rates of many health issues and lower hospital use. It also underscores the value of understanding drivers of heterogeneity within newcomers, such as the circumstances of admission and settlement in their new country.

Building Bridges to Housing for homeless adults with intellectual and developmental disabilities: outcomes of a cross-sector intervention.

BACKGROUND: Adults with intellectual and developmental disabilities (IDD) have high rates of homelessness. This observational study evaluates Bridges to Housing, a cross-sector intervention offering immediate access to housing and supports to this population in Toronto, Canada. METHODS: Twenty-six participants, enrolled between April 2016 and December 2017, were assessed at baseline, six and 12 months post-enrolment. Descriptive statistics and generalized linear modelling evaluated quality of life (QOL) and service needs outcomes. Twenty-one service users and providers participated in semi-structured interviews between August 2017 and June 2018 to elicit their experiences of the intervention, which were analysed thematically. RESULTS: Twelve months post-enrolment, 24 participants were successfully housed and reported increased QOL scores (F(2,43) = 13.73, p = <.001) and decreased perceived unmet service needs (Wald χ2 (2) = 12.93, p = .002). Individual-, intervention- and system-level characteristics facilitated housing stability in this population. CONCLUSIONS: Cross-sector approaches can improve outcomes for homeless adults with IDD and may have an important role in supporting this marginalized population.

Human dengue virus serotype 2 neutralizing antibodies target two distinct quaternary epitopes.

Dengue virus (DENV) infection causes dengue fever, dengue hemorrhagic fever and dengue shock syndrome. It is estimated that a third of the world's population is at risk for infection, with an estimated 390 million infections annually. Dengue virus serotype 2 (DENV2) causes severe epidemics, and the leading tetravalent dengue vaccine has lower efficacy against DENV2 compared to the other 3 serotypes. In natural DENV2 infections, strongly neutralizing type-specific antibodies provide protection against subsequent DENV2 infection. While the epitopes of some human DENV2 type-specific antibodies have been mapped, it is not known if these are representative of the polyclonal antibody response. Using structure-guided immunogen design and reverse genetics, we generated a panel of recombinant viruses containing amino acid alterations and epitope transplants between different serotypes. Using this panel of recombinant viruses in binding, competition, and neutralization assays, we have finely mapped the epitopes of three human DENV2 type-specific monoclonal antibodies, finding shared and distinct epitope regions. Additionally, we used these recombinant viruses and polyclonal sera to dissect the epitope-specific responses following primary DENV2 natural infection and monovalent vaccination. Our results demonstrate that antibodies raised following DENV2 infection or vaccination circulate as separate populations that neutralize by occupying domain III and domain I quaternary epitopes. The fraction of neutralizing antibodies directed to different epitopes differs between individuals. The identification of these epitopes could potentially be harnessed to evaluate epitope-specific antibody responses as correlates of protective immunity, potentially improving vaccine design.

Cutting Edge: Transcriptional Profiling Reveals Multifunctional and Cytotoxic Antiviral Responses of Zika Virus-Specific CD8+ T Cells.

Zika virus (ZIKV) constitutes an increasing public health problem. Previous studies have shown that CD8+ T cells play an important role in ZIKV-specific protective immunity. We have previously defined antigenic targets of the ZIKV-specific CD8+ T cell response in humans. In this study, we characterized the quality and phenotypes of these responses by a combined use of flow cytometry and transcriptomic methods, using PBMCs from donors deriving from different geographical locations collected in the convalescent phase of infection. We show that ZIKV-specific CD8+ T cells are characterized by a polyfunctional IFN-γ signature with upregulation of TNF-α, TNF receptors, and related activation markers, such as CD69, as well as a cytotoxic signature characterized by strong upregulation of GZMB and CRTAM. The signature is stable and not influenced by previous dengue virus exposure, geographical location, or time of sample collection postinfection. To our knowledge, this work elucidates the first in-depth characterization of human CD8+ T cells responding to ZIKV infection.