A measles-vectored vaccine candidate expressing prefusion-stabilized SARS-CoV-2 spike protein brought to phase I/II clinical trials: candidate selection in a preclinical murine model.

In the early COVID-19 pandemic with urgent need for countermeasures, we aimed at developing a replicating viral vaccine using the highly efficacious measles vaccine as vector, a promising technology with prior clinical proof of concept. Building on our successful pre-clinical development of a measles virus (MV)-based vaccine candidate against the related SARS-CoV, we evaluated several recombinant MV expressing codon-optimized SARS-CoV-2 spike glycoprotein. Candidate V591 expressing a prefusion-stabilized spike through introduction of two proline residues in HR1 hinge loop, together with deleted S1/S2 furin cleavage site and additional inactivation of the endoplasmic reticulum retrieval signal, was the most potent in eliciting neutralizing antibodies in mice. After single immunization, V591 induced similar neutralization titers as observed in sera of convalescent patients. The cellular immune response was confirmed to be Th1 skewed. V591 conferred long-lasting protection against SARS-CoV-2 challenge in a murine model with marked decrease in viral RNA load, absence of detectable infectious virus loads, and reduced lesions in the lungs. V591 was furthermore efficacious in an established non-human primate model of disease (see companion article [S. Nambulli, N. Escriou, L. J. Rennick, M. J. Demers, N. L. Tilston-Lunel et al., J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23]). Thus, V591 was taken forward into phase I/II clinical trials in August 2020. Unexpected low immunogenicity in humans (O. Launay, C. Artaud, M. Lachâtre, M. Ait-Ahmed, J. Klein et al., eBioMedicine 75:103810, 2022, https://doi.org/10.1016/j.ebiom.2021.103810) revealed that the underlying mechanisms for resistance or sensitivity to pre-existing anti-measles immunity are not yet understood. Different hypotheses are discussed here, which will be important to investigate for further development of the measles-vectored vaccine platform.IMPORTANCESARS-CoV-2 emerged at the end of 2019 and rapidly spread worldwide causing the COVID-19 pandemic that urgently called for vaccines. We developed a vaccine candidate using the highly efficacious measles vaccine as vector, a technology which has proved highly promising in clinical trials for other pathogens. We report here and in the companion article by Nambulli et al. (J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23) the design, selection, and preclinical efficacy of the V591 vaccine candidate that was moved into clinical development in August 2020, 7 months after the identification of SARS-CoV-2 in Wuhan. These unique in-human trials of a measles vector-based COVID-19 vaccine revealed insufficient immunogenicity, which may be the consequence of previous exposure to the pediatric measles vaccine. The three studies together in mice, primates, and humans provide a unique insight into the measles-vectored vaccine platform, raising potential limitations of surrogate preclinical models and calling for further refinement of the platform.

A human immune system (HIS) mouse model that dissociates roles for mouse and human FcR+ cells during antibody-mediated immune responses.

Human immune system (HIS) mice provide a model to study human immune responses in vivo. Currently available HIS mouse models may harbor mouse Fc Receptor (FcR)-expressing cells that exert potent effector functions following administration of human Ig. Previous studies showed that the ablation of the murine FcR gamma chain (FcR-γ) results in loss of antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis in vivo. We created a new FcR-γ-deficient HIS mouse model to compare host (mouse) versus graft (human) effects underlying antibody-mediated immune responses in vivo. FcR-γ-deficient HIS recipients lack expression and function of mouse activating FcRs and can be stably and robustly reconstituted with human immune cells. By screening blood B-cell depletion by rituximab Ig variants, we found that human FcγRs-mediated IgG1 effects, whereas mouse activating FcγRs were dominant in IgG4 effects. Complement played a role as an IgG1 variant (IgG1 K322A) lacking complement binding activity was largely ineffective. Finally, we provide evidence that FcγRIIIA on human NK cells could mediate complement-independent B-cell depletion by IgG1 K322A. We anticipate that our FcR-γ-deficient HIS model will help clarify mechanisms of action of exogenous administered human antibodies in vivo.

The AMA1-RON complex drives Plasmodium sporozoite invasion in the mosquito and mammalian hosts.

Plasmodium sporozoites that are transmitted by blood-feeding female Anopheles mosquitoes invade hepatocytes for an initial round of intracellular replication, leading to the release of merozoites that invade and multiply within red blood cells. Sporozoites and merozoites share a number of proteins that are expressed by both stages, including the Apical Membrane Antigen 1 (AMA1) and the Rhoptry Neck Proteins (RONs). Although AMA1 and RONs are essential for merozoite invasion of erythrocytes during asexual blood stage replication of the parasite, their function in sporozoites was still unclear. Here we show that AMA1 interacts with RONs in mature sporozoites. By using DiCre-mediated conditional gene deletion in P. berghei, we demonstrate that loss of AMA1, RON2 or RON4 in sporozoites impairs colonization of the mosquito salivary glands and invasion of mammalian hepatocytes, without affecting transcellular parasite migration. Three-dimensional electron microscopy data showed that sporozoites enter salivary gland cells through a ring-like structure and by forming a transient vacuole. The absence of a functional AMA1-RON complex led to an altered morphology of the entry junction, associated with epithelial cell damage. Our data establish that AMA1 and RONs facilitate host cell invasion across Plasmodium invasive stages, and suggest that sporozoites use the AMA1-RON complex to efficiently and safely enter the mosquito salivary glands to ensure successful parasite transmission. These results open up the possibility of targeting the AMA1-RON complex for transmission-blocking antimalarial strategies.

Acute Erythroid Leukemia: From Molecular Biology to Clinical Outcomes.

Acute Erythroid Leukemia (AEL) is a rare and aggressive subtype of Acute Myeloid Leukemia (AML). In 2022, the World Health Organization (WHO) defined AEL as a biopsy with ≥30% proerythroblasts and erythroid precursors that account for ≥80% of cellularity. The International Consensus Classification refers to this neoplasm as "AML with mutated TP53". Classification entails ≥20% blasts in blood or bone marrow biopsy and a somatic TP53 mutation (VAF > 10%). This type of leukemia is typically associated with biallelic TP53 mutations and a complex karyotype, specifically 5q and 7q deletions. Transgenic mouse models have implicated several molecules in the pathogenesis of AEL, including transcriptional master regulator GATA1 (involved in erythroid differentiation), master oncogenes, and CDX4. Recent studies have also characterized AEL by epigenetic regulator mutations and transcriptome subgroups. AEL patients have overall poor clinical outcomes, mostly related to their poor response to the standard therapies, which include hypomethylating agents and intensive chemotherapy. Allogeneic bone marrow transplantation (AlloBMT) is the only potentially curative approach but requires deep remission, which is very challenging for these patients. Age, AlloBMT, and a history of antecedent myeloid neoplasms further affect the outcomes of these patients. In this review, we will summarize the diagnostic criteria of AEL, review the current insights into the biology of AEL, and describe the treatment options and outcomes of patients with this disease.

Seroprevalence of Severe Acute Respiratory Syndrome Coronavirus 2 Among Skilled Nursing Facility Residents and Staff Members-Los Angeles County, August-September 2020.

BACKGROUND: The prevalence of current or past coronavirus disease 2019 in skilled nursing facility (SNF) residents is unknown because of asymptomatic infection and constrained testing capacity early in the pandemic. We conducted a seroprevalence survey to determine a more comprehensive prevalence of past coronavirus disease 2019 in Los Angeles County SNF residents and staff members. METHODS: We recruited participants from 24 facilities; participants were requested to submit a nasopharyngeal swab sample for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) testing and a serum sample for detection of SARS-CoV-2 antibodies. All participants were cross-referenced with our surveillance database to identify persons with prior positive SARS-CoV-2 results. RESULTS: From 18 August to 24 September 2020, we enrolled 3305 participants (1340 residents and 1965 staff members). Among 856 residents providing serum samples, 362 (42%) had current or past SARS-CoV-2 infection. Of the 346 serology-positive residents, 199 (58%) did not have a documented prior positive SARS-CoV-2 PCR result. Among 1806 staff members providing serum, 454 (25%) had current or past SARS-CoV-2 infection. Of the 447 serology-positive staff members, 353 (79%) did not have a documented prior positive SARS-CoV-2 PCR result. CONCLUSIONS: Past testing practices and policies missed a substantial number of SARS-CoV-2 infections in SNF residents and staff members.

Plasmodium sporozoites on the move: Switching from cell traversal to productive invasion of hepatocytes.

Parasites of the genus Plasmodium, the etiological agent of malaria, are transmitted through the bite of anopheline mosquitoes, which deposit sporozoites into the host skin. Sporozoites migrate through the dermis, enter the bloodstream, and rapidly traffic to the liver. They cross the liver sinusoidal barrier and traverse several hepatocytes before switching to productive invasion of a final one for replication inside a parasitophorous vacuole. Cell traversal and productive invasion are functionally independent processes that require proteins secreted from specialized secretory organelles known as micronemes. In this review, we summarize the current understanding of how sporozoites traverse through cells and productively invade hepatocytes, and discuss the role of environmental sensing in switching from a migratory to an invasive state. We propose that timely controlled secretion of distinct microneme subsets could play a key role in successful migration and infection of hepatocytes. A better understanding of these essential biological features of the Plasmodium sporozoite may contribute to the development of new strategies to fight against the very first and asymptomatic stage of malaria.

Success of Maternal and Child Health Pipeline Training Programs: Alumni Survey Results.

INTRODUCTION: The Maternal and Child Health (MCH) Pipeline Training Program, promotes development of a diverse health workforce by training undergraduate students from underrepresented minorities. We aimed to evaluate the success of this program based on three domains: (1) demographic characteristics, (2) academic and career development, and (3) attitudes towards the field of MCH and the training programs among graduates. METHODS: Three domains of success were determined through a collaborative effort between current program directors and the funding agency project officers. The survey with questions related to the three domains was distributed via an online platform to graduates from seven sites (one former site and six current sites). Data were analyzed and presented utilizing descriptive statistics. RESULTS: The survey was distributed to 550 graduates, 162 responded (37% response rate). Demographically, 78% were female, 54% were Black/African American, 22% were Latinx and 83% did not report any disability. Eighty percent of respondents applied to graduate/professional schools, 67% received admission. Graduates often continued to work in MCH fields (70%). Majority felt confident and knowledgeable in the field (89%) and agreed the faculty were supportive at their training sites (90%). CONCLUSION: The study highlights successes in recruiting from underrepresented minorities, particularly Black/African Americans and first-time college goers in the family into the MCH Pipeline Training Programs. Programs were successful in furthering academic and career development for most trainees. Attitudes towards MCH and the training programs were overwhelmingly positive. Continued support of these programs is critical in addressing health disparities and achieving health equity.

Success of Maternal and Child Health Pipeline Training Programs: Alumni Survey Results.

INTRODUCTION: The Maternal and Child Health (MCH) Pipeline Training Program, promotes development of a diverse health workforce by training undergraduate students from underrepresented minorities. We aimed to evaluate the success of this program based on three domains: (1) demographic characteristics, (2) academic and career development, and (3) attitudes towards the field of MCH and the training programs among graduates. METHODS: Three domains of success were determined through a collaborative effort between current program directors and the funding agency project officers. The survey with questions related to the three domains was distributed via an online platform to graduates from seven sites (one former site and six current sites). Data were analyzed and presented utilizing descriptive statistics. RESULTS: The survey was distributed to 550 graduates, 162 responded (37% response rate). Demographically, 78% were female, 54% were Black/African American, 22% were Latinx and 83% did not report any disability. Eighty percent of respondents applied to graduate/professional schools, 67% received admission. Graduates often continued to work in MCH fields (70%). Majority felt confident and knowledgeable in the field (89%) and agreed the faculty were supportive at their training sites (90%). CONCLUSION: The study highlights successes in recruiting from underrepresented minorities, particularly Black/African Americans and first-time college goers in the family into the MCH Pipeline Training Programs. Programs were successful in furthering academic and career development for most trainees. Attitudes towards MCH and the training programs were overwhelmingly positive. Continued support of these programs is critical in addressing health disparities and achieving health equity.

Understanding Infection Prevention Practices in Optometry Clinics.

SIGNIFICANCE: The Los Angeles County Department of Public Health investigated an outbreak of epidemic keratoconjunctivitis secondary to adenovirus linked to a single optometry clinic between June and July 2017. Suboptimal infection prevention practices were identified in the implicated clinic. PURPOSE: The purpose of this study was to determine infection prevention practices in optometry clinics within Los Angeles County. METHODS: A 17-question survey on infection prevention practices among a sample of optometry providers in the county was conducted by the Los Angeles County Department of Public Health. The survey was administered via e-mails sent to a local optometric society's Listserv and in person at a local continuing education event for optometrists. The results were analyzed and are represented as percentages. RESULTS: There were 42 responses, 20 via the online survey (response rate, 15%) and 22 via the in-person survey (response rate, 22%). More than half had no written hand-hygiene policy (58.5%, n = 24/41), 46.2% (n = 18/39) did not wear gloves while examining patients with eye drainage, and about half (48.6%, n = 18/37) did not use droplet precautions for patients with respiratory symptoms. The vast majority used multidose eye-drop vials (92.5%, n = 37/40), but 41.6% (n = 15/36) did not discard the vial if the tip came into contact with conjunctiva/skin/environmental surface. To ensure a clean tonometer for each patient, the majority (68.4%, n = 26/38) used 70% isopropyl alcohol, 47.4% (n = 18/38) used noncontact tonometers, and 23.6% (n = 9/38) used disposable tips (answers not mutually exclusive); none used bleach. CONCLUSIONS: Our data highlight several areas of concern in the practice of standard or transmission-based precautions in the sampled population. First, hand-hygiene policies are not well enforced. Second, personal protective equipment is not appropriately used while examining potentially infectious patients. Third, eye-drop vials are not consistently discarded if contaminated with eye secretions. Lastly, a large proportion of surveyed practices use inadequate disinfection techniques of tonometers.

Anxiety and Depression in Autistic College Students: The Freshman Survey Results.

Objective Mental health among undergraduate students is a growing concern in higher education, but relatively little is known about the mental health of autistic college students. In order to better understand the unique needs of this population, the present study examines whether demographic and psychosocial correlates of anxiety and depression differ in autistic first-year college students and their non-autistic peers.  Methods Secondary data analysis was conducted utilizing population-weighted data of full-time college students in their first year attending four-year colleges and universities in 2016, 2018, and 2019. Autistic and non-autistic students who self-identified as having frequent anxiety or depression were compared in terms of demographic characteristics, physical and emotional health, and academic aspirations and achievement. Results The majority of first-year students with frequent anxiety or depression in this sample tended to be white and had parents who completed a bachelor's degree or went to graduate school, with higher rates of male students in the autistic group. While autistic college freshmen with frequent anxiety or depression self-report lower overall quality of physical health (below average or lowest 10% reported by 57.3% vs. 37.1%) and higher rates of learning disabilities (25.3% vs. 4.6%) and psychological disorders (62.3% vs. 29.3%), these students also tend to outperform their non-autistic peers on standardized academic testing. Conclusion As autistic students are investing in themselves through their education and future careers, practitioners and researchers alike should be investing in accessible physical and mental health services in order to help set autistic students up for success in college and beyond.

Plasmodium sporozoites require the protein B9 to invade hepatocytes.

Plasmodium sporozoites are transmitted to a mammalian host during blood feeding by an infected mosquito and invade hepatocytes for initial replication of the parasite into thousands of erythrocyte-invasive merozoites. Here we report that the B9 protein, a member of the 6-cysteine domain protein family, is secreted from sporozoite micronemes and is required for productive invasion of hepatocytes. The N-terminus of B9 forms a beta-propeller domain structurally related to CyRPA, a cysteine-rich protein forming an essential invasion complex in Plasmodium falciparum merozoites. The beta-propeller domain of B9 is essential for sporozoite infectivity and interacts with the 6-cysteine proteins P36 and P52 in a heterologous expression system. Our results suggest that, despite using distinct sets of parasite and host entry factors, Plasmodium sporozoites and merozoites may share common structural modules to assemble protein complexes for invasion of host cells.

Updates to the Autism Intervention Research Network on Physical Health (AIR-P) Research Agenda.

INTRODUCTION: Autistic individuals, now representing one in 36 individuals in the U.S., experience disproportionate physical health challenges relative to non-autistic individuals. The Health Resources and Services Administration's (HRSA) Autism Intervention Research Network on Physical Health (AIR-P) is an interdisciplinary, multi-center Research Network that aims to increase the health, well-being, and quality of life of autistic individuals. The current paper builds on the initial AIR-P Research Agenda (proposed in Year 1) and provides an updated vision for the Network. METHODS: Updates to the Research Agenda were made via the administration of a Qualtrics survey, and disseminated widely to all AIR-P entities, including the Research Node Leaders, Steering Committee, Autistic Researcher Review Board, and collaborating academic and non-academic entities. Network members were tasked with evaluating the Year 1 Research Agenda and proposing additional priorities. RESULTS: Within each Research Node, all Year 1 priorities were endorsed as continued priorities for research on autism and physical health. Specific topics, including co-occurring conditions and self-determination, advocacy, and decision-making, were particularly endorsed. Opportunities for exploratory studies and intervention research were identified across Research Nodes. Qualitative responses providing feedback on additional research priorities were collected. CONCLUSION: The updated AIR-P Research Agenda represents an important step toward enacting large-scale health promotion efforts for autistic individuals across the lifespan. This updated agenda builds on efforts to catalyze autism research in historically underrepresented topic areas while adopting a neurodiversity-oriented approach to health promotion.

A National Cross-Sectional Study of the Characteristics, Strengths, and Challenges of College Students With Attention Deficit Hyperactivity Disorder.

INTRODUCTION: A substantial proportion of college students experience challenges transitioning from pediatrics to the adult healthcare system. Combined internal medicine and pediatrics (Med-Peds) providers are frequently tasked with facilitating this transition and promoting the health and well-being of this population. There is an increasing proportion of college students with Attention Deficit Hyperactivity Disorder (ADHD) in the U.S. This population experiences particularly pronounced challenges navigating the healthcare system and, as a result, often contends with fragmented healthcare. These issues are due to a range of factors, including lack of physician training, education, and resources, as well as a dearth of available research that can inform Med-Peds providers' efforts to support college students with ADHD. METHODS: The current study compared a nationally representative sample of U.S. college freshmen with ADHD to those without ADHD on health, academic, and non-academic capacities. This study analyzed population-weighted data from the Cooperative Institutional Research Program's Freshman Survey. RESULTS: Students with ADHD were more likely to report co-occurring conditions and feelings of depression and overwhelm. They were less likely to report emotional health that was above average or in the highest 10th percentile. Although they reported lower overall academic aspirations, they were more likely to rate themselves in the highest 10th percentile on a range of non-academic capacities. CONCLUSION: The results from this study can inform efforts among Med-Peds providers seeking to promote the health and well-being of college students with ADHD.

A Residency Program Curriculum to Improve Health Care Transitions for Autistic Individuals.

OBJECTIVES: Physical and mental health outcomes of autistic individuals deteriorate during transition to adulthood. The study aims to identify opportunities to improve physician knowledge in health-care transitions (HCT) for autistic individuals by understanding perceived versus experienced facilitators and barriers in overall HCT curriculum implementation in graduate medical education. METHODS: Medicine-Pediatrics program directors participated in a Health Care Transition Residency Curriculum Collaborative Improvement Network and used an iterative process to develop and improve HCT curricula. Pre- and postcollaborative semistructured interviews were administered to program directors. The study occurred over 9 months (July 2018-February 2019). Recurring interview themes were analyzed utilizing Dedoose qualitative coding software and presented utilizing percentages and proportions. RESULTS: Most program directors developed curricula in response to a gap in their current transition curricula. All program directors partially or completely met their goals during the collaborative. The most common types of curricular delivery were didactic (65%) and clinical experience-based (53%). Some tested unique delivery platforms, like the electronic medical record system (29%) and online modules (24%). Program directors often involved residents in the curricular development process and overwhelmingly (65%) felt this was a major facilitator. Competing priorities of faculty (71%) and of residents (53%) were the most common barriers. CONCLUSIONS: Gaps in HCT curricula delivery were primarily attributed to suboptimal health care systems where training occurs, though existing clinical experiences and diverse learning modalities were successfully leveraged. Using a quality improvement framework and actively engaging resident trainees in curriculum development were successful strategies programs used in the development of HCT curricula.

Epidemiology of Exposures, Preceding Illness and Testing History in Children With Multisystem Inflammatory Syndrome in Children in the First 18 Months of the COVID-19 Pandemic, Los Angeles County, California.

We describe the epidemiology of COVID-19 exposure, preceding illness, and SARS-CoV-2 testing in a large population with MIS-C during the first 18 months of the COVID-19 pandemic. The majority of cases had exposure, preceding illness, or positive SARS-CoV-2 testing 4-8 weeks before MIS-C onset. Serology can help establish epidemiological link to COVID-19 when past infection or exposure are unknown.

A mixed methods investigation of college student mental health during the first year of the COVID-19 pandemic.

OBJECTIVE: Researchers collaborated with undergraduate minority students to quantitatively and qualitatively investigate college students' mental health during the first year of the COVID-19 pandemic. PARTICIPANTS: Participants were two convenience samples of diverse college students surveyed in June (n = 128; M age = 21.7, SD = 1.7) and December (n = 242; M age = 20.3, SD = 1.7) of 2020. METHODS: This study administered items from the California Health Interview Survey and open-ended qualitative items via Qualtrics. RESULTS: Across both waves, students reported significant mental health challenges and psychological distress. Students surveyed in December were three to four times more likely to report depression and anxiety. Female and older students reported heightened odds of mental health challenges. Qualitative findings elaborated on contributing factors. CONCLUSION: During the pandemic, college students have experienced pronounced mental health challenges, potentially exacerbated by academic, professional, relational, and environmental stressors and uncertainty.

'People listen more to what actors say': A qualitative study of tuberculosis-related knowledge, behaviours, stigma, and potential interventions in Puducherry, India.

India has made substantial advancements in reducing the burden of tuberculosis (TB), but persons living with active TB (PLWATB) still face myriad challenges in seeking and receiving care, including TB-related stigma. To meet the END TB targets, it is critical that PLWATB engage in care and are able to adhere to treatment. This qualitative study aimed to understand TB-related stigma (perceived, enacted, and internalised) and possible interventions to reduce stigma in Puducherry and Tamil Nadu, India. We conducted 47 in-depth interviews with PLWATB and household members and eight focus group discussions: two each with PLWATB, their household members, healthcare workers, and key informants. We found varying TB-related knowledge: the vast majority of interview participants reported incorrect modes of transmission, although most were also aware that TB is curable. Participants reported high levels of perceived stigma, with nearly two-thirds of PLWATB choosing to hide their disease to avoid being stigmatised in their community. Participants supported interventions including celebrity advocacy and school-based programming to increase community knowledge and reduce enacted stigma as well as support groups and counselling to reduce internalised stigma in PLWATB. This study has the potential to inform future interventions to reduce TB-related stigma in India.

Plasmodium berghei leucine-rich repeat protein 1 downregulates protein phosphatase 1 activity and is required for efficient oocyst development.

Protein phosphatase 1 (PP1) is a key enzyme for Plasmodium development. However, the detailed mechanisms underlying its regulation remain to be deciphered. Here, we report the functional characterization of the Plasmodium berghei leucine-rich repeat protein 1 (PbLRR1), an orthologue of SDS22, one of the most ancient and conserved PP1 interactors. Our study shows that PbLRR1 is expressed during intra-erythrocytic development of the parasite, and up to the zygote stage in mosquitoes. PbLRR1 can be found in complex with PbPP1 in both asexual and sexual stages and inhibits its phosphatase activity. Genetic analysis demonstrates that PbLRR1 depletion adversely affects the development of oocysts. PbLRR1 interactome analysis associated with phospho-proteomics studies identifies several novel putative PbLRR1/PbPP1 partners. Some of these partners have previously been characterized as essential for the parasite sexual development. Interestingly, and for the first time, Inhibitor 3 (I3), a well-known and direct interactant of Plasmodium PP1, was found to be drastically hypophosphorylated in PbLRR1-depleted parasites. These data, along with the detection of I3 with PP1 in the LRR1 interactome, strongly suggest that the phosphorylation status of PbI3 is under the control of the PP1-LRR1 complex and could contribute (in)directly to oocyst development. This study provides new insights into previously unrecognized PbPP1 fine regulation of Plasmodium oocyst development through its interaction with PbLRR1.