Lassa fever research priorities: towards effective medical countermeasures by the end of the decade.

In 2016, WHO designated Lassa fever a priority disease for epidemic preparedness as part of the WHO Blueprint for Action to Prevent Epidemics. One aspect of preparedness is to promote development of effective medical countermeasures (ie, diagnostics, therapeutics, and vaccines) against Lassa fever. Diagnostic testing for Lassa fever has important limitations and key advancements are needed to ensure rapid and accurate diagnosis. Additionally, the only treatment available for Lassa fever is ribavirin, but controversy exists regarding its effectiveness. Finally, no licensed vaccines are available for the prevention and control of Lassa fever. Ongoing epidemiological and behavioural studies are also crucial in providing actionable information for medical countermeasure development, use, and effectiveness in preventing and treating Lassa fever. This Personal View provides current research priorities for development of Lassa fever medical countermeasures based on literature published primarily in the last 5 years and consensus opinion of 20 subject matter experts with broad experience in public health or the development of diagnostics, therapeutics, and vaccines for Lassa fever. These priorities provide an important framework to ensure that Lassa fever medical countermeasures are developed and readily available for use in endemic and at-risk areas by the end of the decade.

A service mapping exercise of four health and social care staff mental health and wellbeing services, Resilience Hubs, to describe health service provision and interventions.

BACKGROUND: NHS England funded 40 Mental Health and Wellbeing Hubs to support health and social care staff affected by the COVID-19 pandemic. We aimed to document variations in how national guidance was adapted to the local contexts of four Hubs in the North of England. METHODS: We used a modified version of Price's (2019) service mapping methodology. Service level data were used to inform the analysis. A mapping template was adapted from a range of tools, including the European Service Mapping Schedule, and reviewed by Hub leads. Key data included service model; staffing; and interventions. Data were collected between March 2021 - March 2022 by site research assistants. Findings were accuracy-checked by Hub leads, and a logic model developed to theorise how the Hubs may effect change. RESULTS: Hub goals and service models closely reflected guidance; offering: proactive outreach; team-based support; clinical assessment; onward referral, and rapid access to mental health support (in-house and external). Implementation reflected a service context of a client group with high mental health need, and high waiting times at external mental health services. Hubs were predominantly staffed by experienced clinicians, to manage these mental health presentations and organisational working. Formulation-based psychological assessment and the provision of direct therapy were not core functions of the NHS England model, however all Hubs incorporated these adaptations into their service models in response to local contexts, such as extensive waiting lists within external services, and/or client presentations falling between gaps in existing service provision. Finally, a standalone clinical records system was seen as important to reassure Hub users of confidentiality. Other more nuanced variation depended on localised contexts. CONCLUSION: This study provides a map for setting up services, emphasising early understandings of how new services will integrate within existing systems. Local and regional contexts led to variation in service configuration. Whilst additional Hub functions are supported by available literature, further research is needed to determine whether these functions should comprise essential components of staff wellbeing services moving forward. Future research should also determine the comparative effectiveness of service components, and the limits of permissible variation. STUDY REGISTRATION: researchregistry6303.

Vaccine value profile for Chikungunya.

Chikungunya virus (CHIKV) a mosquito-borne alphavirus is the causative agent of Chikungunya (CHIK), a disease with low mortality but high acute and chronic morbidity resulting in a high overall burden of disease. After the acute disease phase, chronic disease including persistent arthralgia is very common, and can cause fatigue and pain that is severe enough to limit normal activities. On average, around 40% of people infected with CHIKV will develop chronic arthritis, which may last for months or years. Recommendations for protection from CHIKV focus on infection control through preventing mosquito proliferation. There is currently no licensed antiviral drug or vaccine against CHIKV. Therefore, one of the most important public health impacts of vaccination would be to decrease burden of disease and economic losses in areas impacted by the virus, and prevent or reduce chronic morbidity associated with CHIK. This benefit would particularly be seen in Low and Middle Income Countries (LMIC) and socio-economically deprived areas, as they are more likely to have more infections and more severe outcomes. This 'Vaccine Value Profile' (VVP) for CHIK is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic and societal value of vaccines in the development pipeline and vaccine-like products.This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships, and multi-lateral organizations. All contributors have extensive expertise on various elements of the CHIK VVP and collectively aimed to identify current research and knowledge gaps.The VVP was developed using only existing and publicly available information.

Identification of the flavivirus conserved residues in the envelope protein hinge region for the rational design of a candidate West Nile live-attenuated vaccine.

The flavivirus envelope protein is a class II fusion protein that drives flavivirus-cell membrane fusion. The membrane fusion process is triggered by the conformational change of the E protein from dimer in the virion to trimer, which involves the rearrangement of three domains, EDI, EDII, and EDIII. The movement between EDI and EDII initiates the formation of the E protein trimer. The EDI-EDII hinge region utilizes four motifs to exert the hinge effect at the interdomain region and is crucial for the membrane fusion activity of the E protein. Using West Nile virus (WNV) NY99 strain derived from an infectious clone, we investigated the role of eight flavivirus-conserved hydrophobic residues in the EDI-EDII hinge region in the conformational change of E protein from dimer to trimer and viral entry. Single mutations of the E-A54, E-I130, E-I135, E-I196, and E-Y201 residues affected infectivity. Importantly, the E-A54I and E-Y201P mutations fully attenuated the mouse neuroinvasive phenotype of WNV. The results suggest that multiple flavivirus-conserved hydrophobic residues in the EDI-EDII hinge region play a critical role in the structure-function of the E protein and some contribute to the virulence phenotype of flaviviruses as demonstrated by the attenuation of the mouse neuroinvasive phenotype of WNV. Thus, as a proof of concept, residues in the EDI-EDII hinge region are proposed targets to engineer attenuating mutations for inclusion in the rational design of candidate live-attenuated flavivirus vaccines.

Fractional Dosing of Yellow Fever Live Attenuated 17D Vaccine: A Perspective.

Yellow fever virus (YFV) is a mosquito-borne flavivirus that causes over 109,000 severe infections and over 51,000 deaths annually in endemic areas of sub-Saharan Africa and tropical South America. The virus has a transmission cycle involving mosquitoes and humans or non-human primates (NHPs) as the vertebrate hosts. Although yellow fever (YF) is prevented by a live attenuated vaccine (strain 17D), recent epidemics in Angola, the Democratic Republic of the Congo (DRC), and Brazil put great pressure on vaccine stockpiles. This resulted in the World Health Organization (WHO) and Pan American Health Organization (PAHO) implementing, on an emergency basis only, off-label dose-sparing techniques and policies during 2016-2018 to protect as many people in DRC and Brazil as possible from disease during unexpected large outbreaks of YF. Subsequently non-inferiority studies involving full doses compared to fractional doses indicated promising results, leading some policy-makers and scientists to consider utilizing YF vaccine fractional doses in non-emergency scenarios. Although the additional data on the immunogenicity and safety of fractional doses are promising, there are several questions and considerations that remain regarding the use of fractional doses, including differences in the initial antibody kinetics, differences in the immune response in certain populations, and durability of the immune response to fractional doses compared to full doses. Until the remaining knowledge gaps are addressed, full doses instead of fractional doses should continue to be used unless there are insufficient doses of the vaccine available to control outbreaks of YF.

A Prototype-Pathogen Approach for the Development of Flavivirus Countermeasures.

Flaviviruses are a genus within the Flaviviridae family of positive-strand RNA viruses and are transmitted principally through mosquito and tick vectors. These viruses are responsible for hundreds of millions of human infections worldwide per year that result in a range of illnesses from self-limiting febrile syndromes to severe neurotropic and viscerotropic diseases and, in some cases, death. A vaccine against the prototype flavivirus, yellow fever virus, has been deployed for 85 years and is highly effective. While vaccines against some medically important flaviviruses are available, others have proven challenging to develop. The emergence and spread of flaviviruses, including dengue virus and Zika virus, demonstrate their pandemic potential. This review highlights the gaps in knowledge that need to be addressed to allow for the rapid development of vaccines against emerging flaviviruses in the future.

Implementing psychological support for health and social care staff affected by the COVID-19 pandemic: a qualitative exploration of staff well-being hubs ('Resilience Hubs') using normalisation process theory.

OBJECTIVES: Evaluate the implementation of Hubs providing access to psychological support for health and social care keyworkers affected by the COVID-19 pandemic. DESIGN: Qualitative interviews informed by normalisation process theory to understand how the Hub model became embedded into normal practice, and factors that disrupted normalisation of this approach. SETTING: Three Resilience Hubs in the North of England. PARTICIPANTS: Hub staff, keyworkers who accessed Hub support (Hub clients), keyworkers who had not accessed a Hub, and wider stakeholders involved in the provision of staff support within the health and care system (N=63). RESULTS: Hubs were generally seen as an effective way of supporting keyworkers, and Hub clients typically described very positive experiences. Flexibility and adaptability to local needs were strongly valued. Keyworkers accessed support when they understood the offer, valuing a confidential service that was separate from their organisation. Confusion about how Hubs differed from other support prevented some from enrolling. Beliefs about job roles, unsupportive managers, negative workplace cultures and systemic issues prevented keyworkers from valuing mental health support. Lack of support from managers discouraged keyworker engagement with Hubs. Black, Asian and minority ethnic keyworkers impacted by racism felt that the Hubs did not always meet their needs. CONCLUSIONS: Hubs were seen as a valuable, responsive and distinct part of the health and care system. Findings highlight the importance of improving promotion and accessibility of Hubs, and continuation of confidential Hub support. Policy implications for the wider health and care sector include the central importance of genuine promotion of and value placed on mental health support by health and social care management, and the creation of psychologically safe work environments. Diversity and cultural competency training is needed to better reach under-represented communities. Findings are consistent with the international literature, therefore, likely to have applicability outside of the current context.

Trajectories of distress and recovery, secondary stressors and social cure processes in people who used the resilience hub after the Manchester Arena bombing.

BACKGROUND: Terrorist incidents lead to a range of mental health outcomes for people affected, sometimes extending years after the event. Secondary stressors can exacerbate them, and social support can provide mitigation and aid recovery. There is a need to better understand distress and mitigating factors among survivors of the Manchester Arena attack in 2017. AIMS: We explored three questions. First, what experiences of distress did participants report? Second, how might secondary stressors have influenced participants' psychosocial recoveries? Third, what part has social support played in the relationships between distress and participants' recovery trajectories? METHOD: We conducted a cross-sectional online survey of a convenience sample of survivors of the Manchester Arena bombing (N = 84) in January 2021 (3 years 8 months post-incident), and a longitudinal study of the same participants' scores on mental health measures over 3 years from September 2017. RESULTS: Survivors' mental well-being scores in early 2021 were significantly lower than general population norms. Longitudinal follow-up provided evidence of enduring distress. Secondary stressors, specifically disruptions to close relationships, were associated with greater post-event distress and slower recovery. We found an indirect relationship between identifying with, and receiving support from, others present at the event and mental well-being >3 years later. CONCLUSIONS: The Arena attack has had an enduring impact on mental health, even in survivors who had a mild response to the event. The quality of close relationships is pivotal to long-term outcome. Constructive support from family and friends, and people with shared experiences, are key to social cure processes that facilitate coping and recovery.

Blocking NS3-NS4B interaction inhibits dengue virus in non-human primates.

Dengue is a major health threat and the number of symptomatic infections caused by the four dengue serotypes is estimated to be 96 million1 with annually around 10,000 deaths2. However, no antiviral drugs are available for the treatment or prophylaxis of dengue. We recently described the interaction between non-structural proteins NS3 and NS4B as a promising target for the development of pan-serotype dengue virus (DENV) inhibitors3. Here we present JNJ-1802-a highly potent DENV inhibitor that blocks the NS3-NS4B interaction within the viral replication complex. JNJ-1802 exerts picomolar to low nanomolar in vitro antiviral activity, a high barrier to resistance and potent in vivo efficacy in mice against infection with any of the four DENV serotypes. Finally, we demonstrate that the small-molecule inhibitor JNJ-1802 is highly effective against viral infection with DENV-1 or DENV-2 in non-human primates. JNJ-1802 has successfully completed a phase I first-in-human clinical study in healthy volunteers and was found to be safe and well tolerated4. These findings support the further clinical development of JNJ-1802, a first-in-class antiviral agent against dengue, which is now progressing in clinical studies for the prevention and treatment of dengue.

Differences in Genetic Diversity of Mammalian Tick-Borne Flaviviruses.

The genetic diversities of mammalian tick-borne flaviviruses are poorly understood. We used next-generation sequencing (NGS) to deep sequence different viruses and strains belonging to this group of flaviviruses, including Central European tick-borne encephalitis virus (TBEV-Eur), Far Eastern TBEV (TBEV-FE), Langat (LGTV), Powassan (POWV), Deer Tick (DTV), Kyasanur Forest Disease (KFDV), Alkhurma hemorrhagic fever (AHFV), and Omsk hemorrhagic fever (OHFV) viruses. DTV, AHFV, and KFDV had the lowest genetic diversity, while POWV strains LEIV-5530 and LB, OHFV, TBEV-Eur, and TBEV-FE had higher genetic diversities. These findings are compatible with the phylogenetic relationships between the viruses. For DTV and POWV, the amount of genetic diversity could be explained by the number of tick vector species and amplification hosts each virus can occupy, with low diversity DTV having a more limited vector and host pool, while POWV with higher genetic diversities has been isolated from different tick species and mammals. It is speculated that high genetic diversity may contribute to the survival of the virus as it encounters these different environments.

Survivors' experiences of informal social support in coping and recovering after the 2017 Manchester Arena bombing.

BACKGROUND: Much of the psychosocial care people receive after major incidents and disasters is informal and is provided by families, friends, peer groups and wider social networks. Terrorist attacks have increased in recent years. Therefore, there is a need to better understand and facilitate the informal social support given to survivors. AIMS: We addressed three questions. First, what is the nature of any informal support-seeking and provision for people who experienced the 2017 Manchester Arena terrorist attack? Second, who provided support, and what makes it helpful? Third, to what extent do support groups based on shared experience of the attack operate as springboards to recovery? METHOD: Semi-structured interviews were carried out with a purposive sample of 18 physically non-injured survivors of the Manchester Arena bombing, registered at the NHS Manchester Resilience Hub. Interview transcripts were thematically analysed. RESULTS: Participants often felt constrained from sharing their feelings with friends and families, who were perceived as unable to understand their experiences. They described a variety of forms of helpful informal social support, including social validation, which was a feature of support provided by others based on shared experience. For many participants, accessing groups based on shared experience was an important factor in their coping and recovery, and was a springboard to personal growth. CONCLUSIONS: We recommend that people who respond to survivors' psychosocial and mental healthcare needs after emergencies and major incidents should facilitate interventions for survivors and their social networks that maximise the benefits of shared experience and social validation.

WHO working group meeting to amend WHO Recommendations to assure the quality, safety and efficacy of live attenuated yellow fever vaccines.

The current WHO Recommendations to assure the quality, safety and efficacy of live attenuated yellow fever vaccines were adopted in 2010. This document recommends that vaccine virus master and working seed lots should be tested for viscerotropism, immunogenicity and neurovirulence in monkeys. A vaccine manufacturer has reported, recently, discrepancies on the clinical scoring of monkeys during assessment of working seed lots and suggested aligning neurotropism assessment of yellow fever vaccines virus seed lots with that of neurovirulence testing of polio vaccines virus seed lots. In this approach, clinical signs are recorded but do not form part of the assessment or pass/fail criteria. At its 71st meeting in August 2020, the ECBS agreed to establish a drafting group and to consult with manufacturers and other stakeholders on the proposed amendment. Then a survey had been conducted to seek opinions of stakeholders on the neurotropism testing and revision of current WHO Recommendations for yellow fever vaccines. It was recognized from the answers of the survey that the test for neurovirulence in monkeys presents several technical challenges which could be addressed in the amended version of the Recommendations. On 18-19 March 2021, a virtual WHO working group meeting was held to discuss a proposed draft of the amended text with participants of yellow fever vaccine manufacturers and relevant regulators. Overall, there was a consensus among manufacturers and regulators that clinical evaluation provides important information and should be retained as part of the neurotropism test. However, there was also agreement that the test is somewhat subjective, and that analysis can be difficult. It was recognized that there was potential for improvement in both test execution and analysis to increase harmonization between manufacturers. Alternative tests to the non-human primates neurovirulence test would be useful but it was agreed that none seem to be sufficiently developed at present. Based on these working group discussions, it was proposed that the appendix on neurotropism test to be further revised by the WHO drafting group and submitted to ECBS for review and adoption. Issues other than neurotropism test were discussed in the meeting as well. There were a number of points identified during the meeting, such as new platform of production, animal models, deep sequencing, international standards, that are outside the current recommendations that are worthy of further discussion. Therefore, it is recommended that there would be a future meeting with various stakeholders to discuss the potential revision of the whole Recommendations for yellow fever vaccines in order to meet the current needs.

Genetic Diversity Does Not Contribute to Attenuation of HeLa Passaged Wild-Type Yellow Fever Virus Strain French Viscerotropic Virus.

The disease yellow fever was prevented by two live attenuated vaccines, strains 17D and French neurotropic vaccine (FNV), derived by serial passage of wild-type (WT) strains Asibi and French Viscerotropic virus (FVV), respectively. Both 17D and FNV displayed decreased genetic diversity and resistance to the antiviral Ribavirin compared to their WT parental strains, which are thought to contribute to their attenuated phenotypes. Subsequent studies found that only a few passages of WT strain FVV in HeLa cells resulted in an attenuated virus. In the current study, the genome sequence of FVV following five passages in HeLa cells (FVV HeLa p5) was determined through Next Generation Sequencing (NGS) with the aim to investigate the molecular basis of viral attenuation. It was found that WT FVV and FVV HeLa p5 virus differed by five amino acid substitutions: E-D155A, E-K331R, E-I412V, NS2A-T105A, and NS4B-V98I. Surprisingly, the genetic diversity and Ribavirin resistance of the FVV HeLa p5 virus were not statistically different to WT parent FVV. These findings suggest that while FVV HeLa p5 is attenuated, this is not dependent on a high-fidelity replication complex, characterized by reduced genetic diversity or increased Ribavirin stability, as seen with FNV and 17D vaccines.

Impact of yellow fever virus envelope protein on wild-type and vaccine epitopes and tissue tropism.

The envelope (E) protein of flaviviruses is functionally associated with viral tissue tropism and pathogenicity. For yellow fever virus (YFV), viscerotropic disease primarily involving the liver is pathognomonic for wild-type (WT) infection. In contrast, the live-attenuated vaccine (LAV) strain 17D does not cause viscerotropic disease and reversion to virulence is associated with neurotropic disease. The relationship between structure-function of the E protein for WT strain Asibi and its LAV derivative 17D strain is poorly understood; however, changes to WT and vaccine epitopes have been associated with changes in virulence. Here, a panel of Asibi and 17D infectious clone mutants were generated with single-site mutations at the one membrane residue and each of the eight E protein amino acid substitutions that distinguish the two strains. The mutants were characterized with respect to WT-specific and vaccine-specific monoclonal antibodies (mAbs) binding to virus plus binding of virus to brain, liver, and lung membrane receptor preparations (MRPs) generated from AG129 mice. This approach shows that amino acids in the YFV E protein domains (ED) I and II contain the WT E protein epitope, which overlap with those that mediate YFV binding to mouse liver. Furthermore, amino acids in EDIII associated with the vaccine epitope overlap with those that facilitate YFV binding mouse brain MRPs. Taken together, these data suggest that the YFV E protein is a key determinant in the phenotype of WT and 17D vaccine strains of YFV.

Baseline mapping of Oropouche virology, epidemiology, therapeutics, and vaccine research and development.

Oropouche virus (OROV) is an arthropod-borne orthobunyavirus found in South America and causes Oropouche fever, a febrile infection similar to dengue. It is the second most prevalent arthropod-borne viral disease in South America after dengue. Over 500,000 cases have been diagnosed since the virus was first discovered in 1955; however, this is likely a significant underestimate given the limited availability of diagnostics. No fatalities have been reported to date, however, up to 60% of cases have a recurrent phase of disease within one month of recovery from the primary disease course. The main arthropod vector is the biting midge Culicoides paraensis, which has a geographic range as far north as the United States and demonstrates the potential for OROV to geographically expand. The transmission cycle is incompletely understood and vertebrate hosts include both non-human primates and birds further supporting the potential ability of the virus to spread. A number of candidate antivirals have been evaluated against OROV in vitro but none showed antiviral activity. Surprisingly, there is only one report in the literature on candidate vaccines. We suggest that OROV is an undervalued pathogen much like chikungunya, Schmallenberg, and Zika viruses were before they emerged. Overall, OROV is an important emerging disease that has been under-investigated and has the potential to cause large epidemics in the future. Further research, in particular candidate vaccines, is needed for this important pathogen.

People's experiences of distress and psychosocial care following a terrorist attack: interviews with survivors of the Manchester Arena bombing in 2017.

BACKGROUND: Distress after major incidents is widespread among survivors. The great majority do not meet the criteria for mental health disorders and rely on psychosocial care provided by their informal networks and official response services. There is a need to better understand their experiences of distress and psychosocial care needs. AIMS: The aims of our study were to enhance understanding of the experience of distress among people present at the Manchester Arena bombing in 2017, identify their experiences of psychosocial care after the incident and learn how to better deliver and target effective psychosocial care following major incidents. METHOD: We conducted a thematic analysis of semi-structured interviews with 18 physically non-injured survivors of the Manchester Arena attack, who registered with the NHS Manchester Resilience Hub. RESULTS: Distress was ubiquitous, with long-lasting health and social consequences. Initial reluctance to seek help from services was also common. Early and open access to authoritative sources of information and emotional support, and organised events for survivors, were viewed as helpful interventions. Inappropriate forms of psychosocial and mental healthcare were common and potent stressors that affected coping and recovery. CONCLUSIONS: This paper extends our understanding of how people react to major events. Provision for the large group of people who are distressed and require psychosocial care may be inadequate after many incidents. There is a substantial agenda for developing awareness of people's needs for psychosocial interventions, and training practitioners to deliver them. The findings have substantial implications for policy and service design.