Immunogenicity of rVSVΔG-ZEBOV-GP Ebola vaccination in exposed and potentially exposed persons in the Democratic Republic of the Congo

Ophthalmological manifestations and plasma markers of inflammation in Ebola survivors in post-treatment era

This study aimed to characterize ophthalmological manifestations and associated inflammatory markers in EVD survivors in post-treatment era. Case-control study of ophthalmological manifestations and plasma inflammatory biomarker profile in EVD survivors (n = 120) from the 2018-2020 outbreak in DRC, their gender- and age-matched close contacts (n = 120) and non-contact (healthy) controls (n = 120). Expressions of inflammatory markers were assessed using the Olink Explore 384 Assay and compared across study groups before and after stratification by treatment with monoclonal antibodies (mAB114, ZMapp, or Regeneron) or antiviral drug (Remdesivir). Protein profiling was carried out using the Olink statistical package. Mean age (years) was comparable among survivors (29.7 ± 10.6), close contacts (28.9 ± 11.1) and non-contact controls (29.3 ± 10.6) (p = 0.85). Mean time from disease onset to clinical assessment was 3.5 ± 0.5 (2.5-4.2) years in survivors. Optic neuropathy was more common in survivors (6.7%) than in close contacts (0.8%) and non-contacts (0.0%) (p = 0.003). Survivors with optic neuropathy had significantly worse visual acuity in both eyes than those without optic neuropathy (all p < 0.001). Clinical evidence of past anterior uveitis was observed in 2.5% of survivors, 2.9% of close contacts, and 1.8% of healthy controls (p = 0.86). Plasma circulating DGKZ, INFGR1, ERBB3, and MICA-MICB showed differential expression patterns between survivors and controls (all p < 0.05). However, no clear separation could be detected on principal component analysis of multiplexed proteomic data between survivor and control samples. Three proteins (ITM2A, CLEC4D, NCLN) were differentially expressed and related to optic neuropathy. The comparison between treatment groups revealed a trend toward lower protein inflammatory markers in survivors treated with Remdesivir than those treated with monoclonal antibodies. We conclude that in treated EVD survivors, optic neuropathy was the only neuro-ophthalmologic abnormality. Uveitis was far less frequent than reported in West African cohorts. ITM2A, CLEC4D, and NCLN were differentially expressed in EVD survivors with optic neuropathy long after the acute phase of the infection. The true meaning of these findings will need further investigations.

Comparison of EBOV GP IgG antibody reactivity: Results from two immunoassays in the Democratic Republic of the Congo

Ebola virus (EBOV) is a highly infectious pathogen, and its long-term consequences continue to be investigated. With its high fatality rate and potential for reinfection or latent infection, continued development of research tools is of utmost importance. Using a cohort (n = 503) of existing bio-banked specimens from the Democratic Republic of the Congo (DRC) two EBOV glycoprotein (GP) immunoglobulin G (IgG) antibody-detection assays were compared: the gold-standard Filovirus Animal Non-Clinical Group (FANG) and a Multiplex bead-based Immunoassay (MIA) with seven pan-filoviral targets. As not all immunoassays have been shown to detect a vaccine-induced immune response, and previous EBOV serosurveillance has been primarily conducted with singleplex technology, this MIA was assessed as an additional resource. Among the cohort, as sample seroreactivity increased, assay correlation increased (r2=0.80). Correlation was sustained among sub-populations of the cohort-in detecting natural immunity among survivors and vaccine-derived responses. Additionally, when results were binarized by seroreactivity, there was high correlation between the two assays (kappa=0.70) with 71 serodiscordant samples. These data indicate that the MIA is an apt alternative to the singleplex FANG assay in detecting relative seroreactivity and can be used as a potential tool for widespread pan-filovirus serosurveillance in the DRC and similar contexts.

Prevention and post-exposure management of occupational exposure to Ebola virus

There have been significant advances in the prevention and management of Ebola virus disease (EVD) caused by Zaire Ebola virus (ZEBOV), including the development of two effective vaccines, rVSV-ZEBOV and Ad26.ZEBOV/MVA-BN-Filo. In addition, ZEBOV monoclonal antibodies have become first-line therapy for EVD. However, the 2022-23 outbreak of Sudan Ebola virus (SUDV) in Uganda has highlighted the gap in current therapies and vaccines, whose efficacy is uncertain against non-ZEBOV species. Health-care and laboratory staff working in EVD treatment centres or Ebola virus diagnostic and research laboratories face unique risks relating to potential occupational exposure to Ebola viruses. Given the substantial morbidity and mortality associated with EVD, facilities should have strategies in place to manage occupational exposures, including consideration of post-exposure therapies. In this Review, we discuss currently available evidence for prevention and post-exposure prophylaxis of EVD, including therapies currently under evaluation for SUDV.

Ebola virus disease in children: epidemiology, pathogenesis, management, and prevention

Ebola disease is a severe disease with extremely high case-fatality rates ranging from 28-100%. Observations made during the 2013-2016 West African epidemic improved our understanding of the clinical course of Ebola disease and accelerated the study of therapeutic and preventative strategies. The epidemic also highlighted the unique challenges associated with providing optimal care for children during Ebola disease outbreaks. In this review, we outline current understanding of Ebola disease epidemiology, pathogenesis, management, and prevention, highlighting data pertinent to the care of children. IMPACT: In this review, we summarize recent advancements in our understanding of Ebola disease epidemiology, clinical presentation, and therapeutic and preventative strategies. We highlight recent data pertinent to the care of children and pregnant women and identify research gaps for this important emerging viral infection in children.

[Vaccines to prevent Ebola virus disease: current challenges and perspectives]

RELEVANCE

Ebola virus disease (EVD) is an acute infectious disease with an extremely high case fatality rate reaching up to 90%. EVD has become widely known since 2014-2016, when outbreak in West Africa occurred and led to epidemic, which caused travel-related cases on the territory of other continents. There are two vaccines against EVD, prequalified by WHO for emergency use, as well as a number of vaccines, approved by local regulators in certain countries. However, even with the availability of effective vaccines, the lack of data on immune correlates of protection and duration of protective immune response in humans and primates is limiting factor for effectively preventing the spread of EVD outbreaks.

AIMS

This review highlights experience of use of EVD vaccines during outbreaks in endemic areas, summarizes data on vaccine immunogenicity in clinical trials, and discusses perspectives for further development and use of effective EVD vaccines.

ViralVacDB: A manually curated repository of viral vaccines

Over the years, numerous vaccines have been developed against viral infections; however, a complete database that provides comprehensive information on viral vaccines has been lacking. In this review, along with our freely accessible database ViralVacDB, we provide details of the viral vaccines, their type, routes of administration and approving agencies. This repository systematically covers additional information such as disease name, adjuvant, manufacturer, clinical status, age and dosage against 422 viral vaccines, including 145 approved vaccines and 277 in clinical trials. We anticipate that this database will be highly beneficial to researchers and others working in pharmaceuticals and immuno-informatics.