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.

Safety and durable immunogenicity of the TV005 tetravalent dengue vaccine, across serotypes and age groups, in dengue-endemic Bangladesh: a randomised, controlled trial.

BACKGROUND: Morbidity and mortality from dengue virus (DENV) is rapidly growing in the large populations of south Asia. Few formal evaluations of candidate dengue vaccine candidates have been undertaken in India, Pakistan, or Bangladesh. Tetravalent vaccines must be tested for safety and immunogenicity in all age groups and in those previously exposed and naive to DENV infections. TV005 is a live, attenuated tetravalent dengue vaccine. We evaluated the safety and immunogenicity of a single dose of TV005 across age groups in dengue-endemic Bangladesh. METHODS: We performed a randomised, placebo-controlled age de-escalating clinical trial of TV005 at a single clinical site in dengue-endemic Dhaka, Bangladesh, following a technology transfer from the USA. Healthy (as determined by history, clinical examination, and safety laboratory test results) volunteers aged 1-50 years were randomly assigned 3:1 (stratified by four age groups) to receive a single dose of TV005 vaccine or placebo. Participants were followed up for 3 years. The study was double blind and was unmasked at day 180; outcome assessors, clinic staff, and volunteers remained blind throughout. Primary outcomes were safety, evaluated per-protocol as proportion of volunteers with solicited related adverse events of any severity through 28 days post dosing, and post-vaccination seropositivity by day 180 using serotype-specific neutralising antibodies (PRNT50 ≥10). Secondary outcomes included viremia, impact of past dengue exposure, and durability of antibody responses. This study is registered with Clinicaltrials.gov, NCT02678455, and is complete. FINDINGS: Between March 13, 2016, and Feb 14, 2017, 192 volunteers were enrolled into four age groups (adults [18-50 years; 20 male and 28 female], adolescents [11-17 years; 27 male and 21 female], children [5-10 years; 15 male and 33 female], and young children [1-4 years; 29 male and 19 female]) with 48 participant per group. All participants were Bangladeshi. Vaccination was well tolerated and most adverse events were mild. Rash was the most common vaccine-associated solicited adverse event, in 37 (26%) of 144 vaccine recipients versus six (12%) of 48 placebo recipients; followed by fever in seven (5% of 144) and arthralgias in seven (6% of 108), which were only observed in vaccine recipients. Post-vaccine, volunteers of all ages (n=142) were seropositive to most serotypes with 118 (83%) seropositive to DENV 1, 141 (99%) to DENV 2, 137 (96%) to DENV 3, and 124 (87%) to DENV 4, overall by day 180. Post-vaccination, viraemia was not consistently found and antibody titres were higher (10-15-fold for DENV 1-3 and 1·6-fold for DENV 4) in individuals with past dengue exposure compared with the dengue-naive participants (DENV 1 mean 480 [SD 4·0] vs 32 [2·4], DENV 2 1042 [3·2] vs 105 [3·1], DENV 3 1406 [2·8] vs 129 [4·7], and DENV 4 105 [3·3] vs 65 [3·1], respectively). Antibody titres to all serotypes remained stable in most adults (63-86%) after 3 years of follow-up. However, as expected for individuals without past exposure to dengue, titres for DENV 1, 3, and 4 waned by 3 years in the youngest (1-4 year old) cohort (69% seropositive for DENV 2 and 22-28% seropositive for DENV 1, 3, and 4). INTERPRETATION: With 3 years of follow-up, the single-dose tetravalent dengue vaccine, TV005, was well tolerated and immunogenic for all four serotypes in young children to adults, including individuals with no previous dengue exposure. FUNDING: National Institutes of Health-National Institute of Allergy and Infectious Diseases Intramural Research Program and Johns Hopkins University. TRANSLATION: For the Bangla translation of the abstract see Supplementary Materials section.

TV005 dengue vaccine protects against dengue serotypes 2 and 3 in two controlled human infection studies.

BACKGROUNDDisease due to dengue viruses is a growing global health threat, causing 100-400 million cases annually. An ideal dengue vaccine should demonstrate durable protection against all 4 serotypes in phase III efficacy trials, however the lack of circulating serotypes may lead to incomplete efficacy data. Controlled human infection models help downselect vaccine candidates and supply critical data to supplement efficacy trials. We evaluated the efficacy of a leading live-attenuated tetravalent dengue vaccine candidate, TV005, against infection with a newly established dengue serotype 3 or an established serotype 2 challenge virus.METHODSTwo randomized, controlled clinical trials were performed. In study 1, a total of 42 participants received TV005 or placebo (n = 21 each), and 6 months later, all were challenged with dengue 2 virus (rDEN2Δ30) at a dose of 103 PFU. In study 2, a total of 23 participants received TV005 and 20 received placebo, and 6 months later, all were challenged with 104 PFU dengue 3 virus (rDEN3Δ30). The study participants were closely monitored for safety, viremia, and immunologic responses. Infection, measured by post-challenge viremia, and the occurrence of rash and neutropenia were the primary endpoints. Secondary endpoints included safety, immunologic, and virologic profiles following vaccination with TV005 and subsequent challenge with the rDEN2Δ30 or rDEN3Δ30 strain.RESULTSTV005 was well tolerated and protected all vaccinated volunteers from viremia with DENV2 or DENV3 (none infected in either group). Placebo recipients had post-challenge viremia (100% in study 1, 85% in study 2), and all experienced rash following challenge with either serotype.CONCLUSIONSTV005 is a leading tetravalent dengue vaccine candidate that fully protected against infection with DENV2 and DENV3 in an established controlled human infection model.TRIAL REGISTRATIONClinicalTrials.gov NCT02317900 and NCT02873260.FUNDINGIntramural Research Program, NIH (contract HHSN272200900010C).

Trends in hospital coding for people experiencing homelessness in Canada, 2015-2020: a descriptive study.

BACKGROUND: In 2018, hospitals were mandated to record homelessness using International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada (ICD-10-CA code Z59.0). We sought to answer whether the coding mandate affected the volume of patients identified as experiencing homelessness in acute inpatient hospitalizations and if there was any geographic variation. METHODS: We conducted a serial cross-sectional study describing 6 fiscal years (2015/16 to 2020/21) of hospital administrative data from the Hospital Morbidity Database. We reported frequencies and percentages of hospitalizations with a Z59.0 diagnostic code and disaggregated by several types of Canadian geographies. Controlling for fiscal quarter (coded Q1 to Q4) and province or territory, adjusted logistic regression models quantified the odds of Z59.0 being coded during hospital stays. RESULTS: The frequency and percentage of people experiencing homelessness in hospitalization records across Canada increased from 6934 (0.12%) in 2015/16 to 21 529 (0.41%) in 2020/21. Trends varied by province and territory. Recording of the Z59.0 code increased following the mandate (adjusted odds ratio 2.29, 95% confidence interval 2.25-2.32), relative to the pre-mandate period. INTERPRETATION: The 2018 coding mandate coincided with an increase in the use of the Z59.0 code to document homelessness in health care administrative data; however, trends varied by jurisdiction. The ICD-10-CA code Z59.0 presents a promising opportunity for standardized and routinely collected data to identify people experiencing homelessness in hospital administrative data.

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.

Building effective public dental care programs: The critical role of implementation evaluation.

There are significant income-related inequities in oral health and access to oral health care. Public dental programs generally aim to increase access to oral health care for individuals with financial barriers through government payments for appointments. Low engagement from both oral health care providers and intended patients are common challenges in delivery of public dental programs, and are impediments to program impact and outcomes. Still, these programs rarely address the systemic issues that affect the experiences of intended users. This accentuates the importance of monitoring of program delivery to refine or adapt programs to better meet needs of service providers and users. As such, specifying program goals and developing a related monitoring strategy are critical as Canada begins to implement a national public dental program. Drawing on an example of a pediatric public dental program for children from low-income families or with severe disabilities in Ontario, Canada, this article illustrates how an implementation and evaluation framework could be applied to measure implementation and impact of the national program. The RE-AIM framework measures performance across five domains: (1) Reach, (2) Effectiveness (patient level), (3) Adoption, (4) Implementation (provider, setting, and policy levels), and (5) Maintenance (all levels). Given the disparities in oral disease and access to oral health care, the results can be used most effectively to adapt programs if relevant stakeholders participate in reviewing data, investigating quality gaps, and developing improvement strategies.

A Pragmatic Randomized Controlled Trial of Financial Incentives in Case Management for Homeless Adults With Mental Illness.

OBJECTIVE: Financial incentives can facilitate behavior change and service engagement in health care settings, but research on their use with adults experiencing homelessness is limited. This study examined the effectiveness of financial incentives in improving service engagement and health outcomes among homeless adults with mental illness in Toronto. METHODS: The authors of this randomized controlled trial recruited 176 participants receiving brief multidisciplinary case management services for homeless adults with mental illness after hospital discharge. In a 1:1 randomization design, 87 participants received a financial incentive of CAN$20 for every week they remained engaged with the service for up to 6 months. The remaining 89 participants received treatment as usual. The primary outcome was service contact rates for up to 6 months of follow-up. Secondary outcomes included self-reported health status, mental health symptoms, substance use, quality of life, housing stability, acute health service use, and working alliance. Negative binomial regression models, analyses of covariance, generalized estimating equations models, and Wilcoxon rank sum tests were used to examine differences between the financial incentive and treatment-as-usual groups across outcomes of interest. RESULTS: No significant differences were found between the financial incentive and treatment-as-usual groups in service contact rates or any of the secondary outcomes examined over the 6-month period. CONCLUSIONS: In low-barrier, brief case management programs tailored to the needs of adults experiencing homelessness, financial incentives may not affect service engagement or health outcomes. Further research is needed to identify the effect of financial incentives on engagement in other services, including housing-based interventions.

Health conditions and service use of autistic women and men: A retrospective population-based case-control study.

LAY ABSTRACT: This study used administrative data from Ontario, Canada to compare the health conditions and service use of autistic women and men with adults with other developmental disabilities and with adults without developmental disabilities. Autistic women and men were more likely to have physical and mental health conditions compared to adults without developmental disabilities. Rates of health conditions were similar or lower among autistic adults compared to adults with other developmental disabilities, except more autistic adults had psychiatric conditions. Autistic women and men used higher rates of psychiatric services compared to all other groups. When comparing autistic women with same aged autistic men, sex differences were found for specific physical (Crohn's disease/colitis, rheumatoid arthritis) and psychiatric conditions (psychotic disorders, non-psychotic disorders), as well differences in service use (emergency department visits, hospitalizations, family doctor and neurologist visits). These results further highlight the high health needs and service use of autistic women and men, as well as adults with other developmental disabilities. It is critical for future research to focus on mental health support for autistic adults and to better understand how to tailor supports to best serve autistic women.

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.

Using financial incentives to improve health service engagement and outcomes of adults experiencing homelessness: A scoping review of the literature.

People experiencing homelessness (PEH) have high rates of acute and chronic health conditions, complex support needs and often face multiple barriers to accessing health services. Financial incentive (FI) interventions have been found effective in improving service engagement and health outcomes for a range of health conditions, populations and settings, but little is known about their impact on PEH. We conducted a scoping review to explore the impact of FI interventions on treatment retention, adherence and other health outcomes of PEH. We searched seven electronic databases from inception to September 2021 to identify peer-reviewed published English language studies that used FI interventions with adult PEH. A scoping review methodology was used to chart relevant data uniformly. Descriptive statistics and narrative syntheses were used to describe outcomes. Thirty-three quantitative articles related to 29 primary studies were published between 1990 and 2021 and met inclusion criteria. Studies targeted three areas of health behaviour change: decreasing substance use or increasing abstinence rates, preventing or treating infectious diseases or promoting lifestyle/general health goal attainment. A variety of FIs were used (cash/non-cash, escalating/fixed schedule, larger/smaller amounts, some/all behaviours rewarded, certain/uncertain reward) across studies. Twenty-six of the primary studies reported significantly better outcomes for the participants receiving FI compared to controls. There were mixed findings about the efficacy of cash versus non-cash FIs, non-cash FIs versus other interventions and higher versus lower value of incentives. Furthermore, there was limited research about long-term outcomes and impacts. FIs have promise in increasing abstinence from substances, engagement in infectious disease treatment, retention in health services and general lifestyle modifications for PEH. Future research should examine long-term impacts and the contribution of co-interventions and intermediary lifestyle behaviour changes.

'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.

Premature mortality in a population-based cohort of autistic adults in Canada.

Research from different countries suggests that autistic adults are more likely to die prematurely than non-autistic adults, but these studies do not always investigate male and female individuals separately and do not consider whether this pattern is unique to autistic people or is also an issue for people with other developmental disabilities. We examined premature mortality in autistic males and females (assigned at birth) in a population-based cohort, compared to males and females with and without other developmental disabilities. Using linked administrative health and social services population data from Ontario, Canada, age-matched males and females aged 19-65 years were followed between 2010 and 2016, and causes of death were determined. Over the 6-year observation period, 330 of 42,607 persons (0.77%) in the group without developmental disabilities had died compared to 259 of 10,646 persons (2.43%) in the autism group and 419 of 10,615 persons (3.95%) in the other developmental disabilities group. Autistic males and females were more likely to die than non-autistic males (adjusted risk ratio, RR 3.13, 95%CI 2.58-3.79) and non-autistic females (adjusted RR 3.12, 95%CI 2.35-4.13) without developmental disabilities, but were less likely to die than adults with other developmental disabilities (males: adjusted RR 0.66, 95%CI 0.55-0.79; females: adjusted RR 0.55, 95%CI 0.43-0.71). Most common causes of death varied depending on a person's sex and diagnosis. Given the greater likelihood of premature mortality in adults with developmental disabilities including autism, greater attention and resources directed toward their health and social care are needed, tailored to their sex and diagnosis-informed needs. LAY SUMMARY: This study looked at how many autistic men and women died over 6 years (2010-2016), along with how they died, and compared this to adults who did not have autism living in Ontario, Canada. It found that autistic men and women were more than three times as likely to die as people of the same age who did not have a developmental disability. However, adults with other developmental disabilities besides autism were even more likely to die than autistic adults. This means that we have to pay more attention and invest in better social and health care for autistic people, along with people who have other types of developmental disabilities.

The innate immune response following multivalent dengue vaccination and implications for protection against dengue challenge.

Understanding the immune response to dengue virus (DENV) is essential for developing a dengue vaccine that is protective against all 4 DENV serotypes. We evaluated the immune response after vaccination (live attenuated tetravalent dengue vaccine TV005 or trivalent admixture) and after challenge with DEN2Δ30 (Tonga/74) to better understand the importance of homotypic immunity in vaccine protection. Significant increases in IP-10 expression were observed following receipt of either the trivalent or tetravalent vaccine. After challenge, a large increase in IP-10 expression was observed in the placebo and trivalent admixture groups but not in the tetravalent vaccine group. MCP-1, IL-1RA, and MIP-1ß exhibited a similar pattern as IP-10. These results demonstrate protective effects of trivalent and tetravalent vaccines against DENV and suggest that the tetravalent vaccine has a better protective effect compared with the trivalent admixture. We also explored the postvaccination and postchallenge immune response differences between Black and White participants. White participants responded to vaccine differently than Black participants; Black participants receiving trivalent and tetravalent vaccines responded strongly and White participants responded only transiently in trivalent group. In response to challenge, White participants elicited a stronger response than Black participants. These results may explain why White participants may have a more vigorous DENV immune response than Black participants, as reported in literature.

Dengue: A Growing Problem With New Interventions.

Dengue is the disease caused by 1 of 4 distinct, but closely related dengue viruses (DENV-1-4) that are transmitted by Aedes spp. mosquito vectors. It is the most common arboviral disease worldwide, with the greatest burden in tropical and sub-tropical regions. In the absence of effective prevention and control measures, dengue is projected to increase in both disease burden and geographic range. Given its increasing importance as an etiology of fever in the returning traveler or the possibility of local transmission in regions in the United States with competent vectors, as well as the risk for large outbreaks in endemic US territories and associated states, clinicians should understand its clinical presentation and be familiar with appropriate testing, triage, and management of patients with dengue. Control and prevention efforts reached a milestone in June 2021 when the Advisory Committee on Immunization Practices (ACIP) recommended Dengvaxia for routine use in children aged 9 to 16 years living in endemic areas with laboratory confirmation of previous dengue virus infection. Dengvaxia is the first vaccine against dengue to be recommended for use in the United States and one of the first to require laboratory testing of potential recipients to be eligible for vaccination. In this review, we outline dengue pathogenesis, epidemiology, and key clinical features for front-line clinicians evaluating patients presenting with dengue. We also provide a summary of Dengvaxia efficacy, safety, and considerations for use as well as an overview of other potential new tools to control and prevent the growing threat of dengue .

Cross-reactive antibodies facilitate innate sensing of dengue and Zika viruses.

The Aedes aegypti mosquito transmits both dengue virus (DENV) and Zika virus (ZIKV) . Individuals in endemic areas are at risk for infection with both viruses, as well as for repeated DENV infection. In the presence of anti-DENV antibodies, outcomes of secondary DENV infection range from mild to life threatening. Furthermore, the role of cross-reactive antibodies on the course of ZIKV infection remains unclear. We assessed the ability of cross-reactive DENV mAbs or polyclonal immunoglobulin isolated after DENV vaccination to upregulate type I IFN production by plasmacytoid DCs (pDCs) in response to both heterotypic DENV- and ZIKV-infected cells. We found a range in the ability of antibodies to increase pDC IFN production and a positive correlation between IFN production and the ability of an antibody to bind to the infected cell surface. Engagement of Fc receptors on the pDC and engagement of epitope on the infected cell by the Fab portion of the same antibody molecule was required to mediate increased IFN production by providing specificity to and promoting pDC sensing of DENV or ZIKV. This represents a mechanism independent of neutralization by which preexisting cross-reactive DENV antibodies could protect a subset of individuals from severe outcomes during secondary heterotypic DENV or ZIKV infection.

Protocol for a Case Control Study to Evaluate Oral Health as a Biomarker of Child Exposure to Adverse Psychosocial Experiences.

BACKGROUND: The early identification of children who have experienced adversity is critical for the timely delivery of interventions to improve coping and reduce negative consequences. Self-report is the usual practice for identifying children with exposure to adversity. However, physiological characteristics that signal the presence of disease or other exposures may provide a more objective identification strategy. This protocol describes a case-control study that assesses whether exposure to adversity is more common in children with tooth enamel anomalies compared to children without such anomalies. METHODS: For 150 mother-child pairs from a pediatric dental clinic in Toronto, Canada, maternal interviews will assess the child's adverse and resilience-building experiences. Per child, one (exfoliated or extracted) tooth will be assessed for suspected enamel anomalies. If anomalies are present, the child is a case, and if absent, the child is a control. Tooth assessment modalities will include usual practice for dental exams (visual assessment) and modalities with greater sensitivity to identify anomalies. CONCLUSION: If structural changes in children's teeth are associated with exposure to adversity, routine dental exams could provide an opportunity to screen children for experiences of adversity. Affected children could be referred for follow-up.

Peculiarities of Zika Immunity and Vaccine Development: Lessons from Dengue and the Contribution from Controlled Human Infection Model.

The Zika virus (ZIKV) was first isolated from a rhesus macaque in the Zika forest of Uganda in 1947. Isolated cases were reported until 2007, when the first major outbreaks of Zika infection were reported from the Island of Yap in Micronesia and from French Polynesia in 2013. In 2015, ZIKV started to circulate in Latin America, and in 2016, ZIKV was considered by WHO to be a Public Health Emergency of International Concern due to cases of Congenital Zika Syndrome (CZS), a ZIKV-associated complication never observed before. After a peak of cases in 2016, the infection incidence dropped dramatically but still causes concern because of the associated microcephaly cases, especially in regions where the dengue virus (DENV) is endemic and co-circulates with ZIKV. A vaccine could be an important tool to mitigate CZS in endemic countries. However, the immunological relationship between ZIKV and other flaviviruses, especially DENV, and the low numbers of ZIKV infections are potential challenges for developing and testing a vaccine against ZIKV. Here, we discuss ZIKV vaccine development with the perspective of the immunological concerns implicated by DENV-ZIKV cross-reactivity and the use of a controlled human infection model (CHIM) as a tool to accelerate vaccine development.