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1.
Emerg Infect Dis ; 30(5): 854-863, 2024 May.
Article in English | MEDLINE | ID: mdl-38666548

ABSTRACT

Crimean-Congo hemorrhagic fever (CCHF) is a tickborne infection that can range from asymptomatic to fatal and has been described in >30 countries. Early identification and isolation of patients with suspected or confirmed CCHF and the use of appropriate prevention and control measures are essential for preventing human-to-human transmission. Here, we provide an overview of the epidemiology, clinical features, and prevention and control of CCHF. CCHF poses a continued public health threat given its wide geographic distribution, potential to spread to new regions, propensity for genetic variability, and potential for severe and fatal illness, in addition to the limited medical countermeasures for prophylaxis and treatment. A high index of suspicion, comprehensive travel and epidemiologic history, and clinical evaluation are essential for prompt diagnosis. Infection control measures can be effective in reducing the risk for transmission but require correct and consistent application.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/prevention & control , Hemorrhagic Fever, Crimean/transmission , Hemorrhagic Fever, Crimean/diagnosis , Hemorrhagic Fever, Crimean/virology , Humans , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Animals , Ticks/virology
2.
Nat Commun ; 15(1): 1722, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38409240

ABSTRACT

Crimean-Congo hemorrhagic fever virus (CCHFV) is a WHO priority pathogen. Antibody-based medical countermeasures offer an important strategy to mitigate severe disease caused by CCHFV. Most efforts have focused on targeting the viral glycoproteins. However, glycoproteins are poorly conserved among viral strains. The CCHFV nucleocapsid protein (NP) is highly conserved between CCHFV strains. Here, we investigate the protective efficacy of a CCHFV monoclonal antibody targeting the NP. We find that an anti-NP monoclonal antibody (mAb-9D5) protected female mice against lethal CCHFV infection or resulted in a significant delay in mean time-to-death in mice that succumbed to disease compared to isotype control animals. Antibody protection is independent of Fc-receptor functionality and complement activity. The antibody bound NP from several CCHFV strains and exhibited robust cross-protection against the heterologous CCHFV strain Afg09-2990. Our work demonstrates that the NP is a viable target for antibody-based therapeutics, providing another direction for developing immunotherapeutics against CCHFV.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Female , Animals , Mice , Hemorrhagic Fever Virus, Crimean-Congo/metabolism , Nucleocapsid Proteins/metabolism , Antibodies, Monoclonal , Hemorrhagic Fever, Crimean/prevention & control , Glycoproteins/metabolism , Antibodies, Viral
3.
Cell Res ; 34(2): 140-150, 2024 02.
Article in English | MEDLINE | ID: mdl-38182887

ABSTRACT

Crimean-Congo hemorrhagic fever virus (CCHFV) is the most widespread tick-born zoonotic bunyavirus that causes severe hemorrhagic fever and death in humans. CCHFV enters the cell via clathrin-mediated endocytosis which is dependent on its surface glycoproteins. However, the cellular receptors that are required for CCHFV entry are unknown. Here we show that the low density lipoprotein receptor (LDLR) is an entry receptor for CCHFV. Genetic knockout of LDLR impairs viral infection in various CCHFV-susceptible human, monkey and mouse cells, which is restored upon reconstitution with ectopically-expressed LDLR. Mutagenesis studies indicate that the ligand binding domain (LBD) of LDLR is necessary for CCHFV infection. LDLR binds directly to CCHFV glycoprotein Gc with high affinity, which supports virus attachment and internalization into host cells. Consistently, a soluble sLDLR-Fc fusion protein or anti-LDLR blocking antibodies impair CCHFV infection into various susceptible cells. Furthermore, genetic knockout of LDLR or administration of an LDLR blocking antibody significantly reduces viral loads, pathological effects and death following CCHFV infection in mice. Our findings suggest that LDLR is an entry receptor for CCHFV and pharmacological targeting of LDLR may provide a strategy to prevent and treat Crimean-Congo hemorrhagic fever.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Receptors, LDL , Animals , Humans , Mice , Endocytosis , Glycoproteins/metabolism , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever Virus, Crimean-Congo/metabolism , Hemorrhagic Fever, Crimean/prevention & control , Receptors, LDL/metabolism , Virus Internalization
4.
Viruses ; 15(12): 1-15, dez 4, 2023. tab, mapa
Article in English | RSDM | ID: biblio-1531383

ABSTRACT

Emerging zoonotic diseases are an increasing threat to public health. There is little data on the seroprevalence of zoonotic diseases among pastoralists in the country. We aim to carry out a cross-sectional study on the prevalence of major zoonotic diseases among pastoral communities in the Caia and Búzi districts. Methods: Between January and December 2018, a questionnaire was used to solicit socio-demographic data from consenting pastoralists with the collection of blood samples in the Caia and Búzi districts of the Sofala province. All samples were tested using ELISA commercial reagents for the detection of IgM antibodies against Brucella and Leptospira. Likewise, IgM and IgG antibodies against Rickettsia and CCHFV were determined using ELISA kits. Results: A total of 218 samples were tested, of which 43.5% (95/218) were from the district of Caia and 56.4% (123/218) from the Búzi district. Results from both districts showed that the seroprevalence of IgM antibodies against Brucella and Leptospira was 2.7% (6/218) and 30.3% (67/218), respectively. Positivity rates for IgM and IgG anti-Rickettsia and CCHFV were 8.7% (19/218), 2.7% (6/218), 4.1% (9/218), and 0.9% (2/218), respectively. Conclusions: Results from our study showed evidence of antibodies due to exposure to Brucella, Leptospira, Rickettsia, and CCHFV with antibodies against Leptospira and Rickettsia being the most prevalent. Hence, laboratory diagnosis of zoonotic diseases is essential in the early detection of outbreaks, the identification of silent transmission, and the etiology of non-febrile illness in a pastoral community. There is a need to develop public health interventions that will reduce the risk of transmission.


Subject(s)
Humans , Male , Female , Brucella/virology , Hemorrhagic Fever, Crimean/virology , Antibodies, Viral/immunology , Rickettsia/growth & development , Hantaan virus/immunology , Hemorrhagic Fever, Crimean/prevention & control , Leptospira/virology , Mozambique
5.
Front Immunol ; 14: 1238882, 2023.
Article in English | MEDLINE | ID: mdl-37753088

ABSTRACT

Crimean-Congo hemorrhagic fever (CCHF) is the most prevalent tick-borne viral disease affecting humans. The disease is life-threatening in many regions of the developing world, including Africa, Asia, the Middle East, and Southern Europe. In line with the rapidly increasing disease prevalence, various vaccine strategies are under development. Despite a large number of potential vaccine candidates, there are no approved vaccines as of yet. This paper presents a detailed comparative analysis of current efforts to develop vaccines against CCHFV, limitations associated with current efforts, and future research directions.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Humans , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/prevention & control , Africa/epidemiology , Asia/epidemiology , Vaccine Development
6.
Front Cell Infect Microbiol ; 13: 1121163, 2023.
Article in English | MEDLINE | ID: mdl-37026060

ABSTRACT

Crimean-Congo hemorrhagic fever virus (CCHFV) can cause severe hemorrhagic fever in humans and is mainly transmitted by ticks. There is no effective vaccine for Crimean-Congo hemorrhagic fever (CCHF) at present. We developed three DNA vaccines encoding CCHFV nucleocapsid protein (NP), glycoprotein N-terminal (Gn) and C-terminal (Gc) fused with lysosome-associated membrane protein 1 (LAMP1) and assessed their immunogenicity and protective efficacy in a human MHC (HLA-A11/DR1) transgenic mouse model. The mice that were vaccinated three times with pVAX-LAMP1-CCHFV-NP induced balanced Th1 and Th2 responses and could most effectively protect mice from CCHFV transcription and entry-competent virus-like particles (tecVLPs) infection. The mice vaccinated with pVAX-LAMP1-CCHFV-Gc mainly elicited specific anti-Gc and neutralizing antibodies and provided a certain protection from CCHFV tecVLPs infection, but the protective efficacy was less than that of pVAX-LAMP1-CCHFV-NP. The mice vaccinated with pVAX-LAMP1-CCHFV-Gn only elicited specific anti-Gn antibodies and could not provide sufficient protection from CCHFV tecVLPs infection. These results suggest that pVAX-LAMP1-CCHFV-NP would be a potential and powerful candidate vaccine for CCHFV.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Vaccines, DNA , Humans , Animals , Mice , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/prevention & control , Nucleocapsid Proteins/genetics , Vaccines, DNA/genetics , Antibodies, Viral , Glycoproteins/genetics , Transcription Factors/metabolism , Lysosomal Membrane Proteins/genetics
7.
Microb Pathog ; 177: 106054, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36882130

ABSTRACT

Crimean-Congo hemorrhagic fever is a serious vector-borne zoonotic viral infection which leads to severe illness and fatalities in people living in endemic regions and becoming infected sporadically. Hyalomma ticks are responsible for the transmission of the virus which belongs to the family Nairoviridae. This disease spreads through ticks bite, infected tissues, or blood of viremic animals, and from infected humans to others. Serological studies also indicate the presence of the virus in various domestic and wild animals to be a risk factor for the transmission of the disease. Crimean-Congo hemorrhagic fever virus elicits many immune responses during the infection including inflammatory, innate, and adaptive immune responses. The development of an effective vaccine could be a promising method for the control and prevention of disease in endemic areas. The purpose of this review is to highlight the importance of CCHF, its mode of transmission, the interaction of the virus with the hosts and ticks, immunopathogenesis, and advances in immunization.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Ticks , Vaccines , Animals , Humans , Hemorrhagic Fever, Crimean/prevention & control , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever Virus, Crimean-Congo/physiology , Animals, Wild
8.
EBioMedicine ; 90: 104523, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36933409

ABSTRACT

BACKGROUND: The tick-borne bunyavirus, Crimean-Congo Haemorrhagic Fever virus (CCHFV), can cause severe febrile illness in humans and has a wide geographic range that continues to expand due to tick migration. Currently, there are no licensed vaccines against CCHFV for widespread usage. METHODS: In this study, we describe the preclinical assessment of a chimpanzee adenoviral vectored vaccine (ChAdOx2 CCHF) which encodes the glycoprotein precursor (GPC) from CCHFV. FINDINGS: We demonstrate here that vaccination with ChAdOx2 CCHF induces both a humoral and cellular immune response in mice and 100% protection in a lethal CCHF challenge model. Delivery of the adenoviral vaccine in a heterologous vaccine regimen with a Modified Vaccinia Ankara vaccine (MVA CCHF) induces the highest levels of CCHFV-specific cell-mediated and antibody responses in mice. Histopathological examination and viral load analysis of the tissues of ChAdOx2 CCHF immunised mice reveals an absence of both microscopic changes and viral antigen associated with CCHF infection, further demonstrating protection against disease. INTERPRETATION: There is the continued need for an effective vaccine against CCHFV to protect humans from lethal haemorrhagic disease. Our findings support further development of the ChAd platform expressing the CCHFV GPC to seek an effective vaccine against CCHFV. FUNDING: This research was supported by funding from the Biotechnology and Biological Sciences Research Council (UKRI-BBSRC) [BB/R019991/1 and BB/T008784/1].


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Viral Vaccines , Humans , Animals , Mice , Hemorrhagic Fever, Crimean/prevention & control , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Vaccination , Genetic Vectors/genetics , Vaccinia virus
9.
Nat Rev Microbiol ; 21(7): 463-477, 2023 07.
Article in English | MEDLINE | ID: mdl-36918725

ABSTRACT

Crimean-Congo haemorrhagic fever (CCHF) is a severe tick-borne illness with a wide geographical distribution and case fatality rates of 30% or higher. Caused by infection with the CCHF virus (CCHFV), cases are reported throughout Africa, the Middle East, Asia and southern and eastern Europe. The expanding range of the Hyalomma tick vector is placing new populations at risk for CCHF, and no licensed vaccines or specific antivirals exist to treat CCHF. Furthermore, despite cases of CCHF being reported annually, the host and viral determinants of CCHFV pathogenesis are poorly understood. CCHFV can productively infect a multitude of animal species, yet only humans develop a severe illness. Within human populations, subclinical infections are underappreciated and may represent a substantial proportion of clinical outcomes. Compared with other members of the Bunyavirales order, CCHFV has a more complex genomic organization, with many viral proteins having unclear functions in viral pathogenesis. In recent years, improved animal models have led to increased insights into CCHFV pathogenesis, and several antivirals and vaccines for CCHFV have shown robust efficacy in preclinical models. Translation of these insights and candidate therapeutics to the clinic will hopefully reduce the morbidity and mortality caused by CCHFV.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Vaccines , Animals , Humans , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/prevention & control , Hemorrhagic Fever, Crimean/drug therapy , Vaccines/therapeutic use , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Models, Animal
10.
J Spec Oper Med ; 23(1): 92-95, 2023 Mar 15.
Article in English | MEDLINE | ID: mdl-36753717

ABSTRACT

Crimean-Congo Hemorrhagic Fever (CCHF) is the most widespread tickborne virus causing human disease. CCHF wields a mortality rate up to 30% and was responsible for the death of a US Soldier in 2009. The virus is spread by the Hyalomma species of hard tick found across Central Europe, the Middle East, Africa, and Asia south of the 50° parallel. Infection typically consists of a 1-7-day non-specific viral prodrome, followed by onset of hemorrhagic disease on days 7-10. Severe disease may cause thrombocytopenia, transaminitis, petechial hemorrhage, hematemesis, and death typically by day 10 of illness. Education and insect control are paramount to disease prevention. Treatment is predominantly supportive care, though evidence suggests a benefit of early ribavirin administration. CCHF has caused multiple nosocomial outbreaks, and therefore consideration should be given to safe transport and evacuation of infected and exposed patients. Given the wide area of distribution, transmissibility, innocuous arthropod vectors, and high mortality rate, it is imperative that Special Operations Forces (SOF) providers be aware of CCHF and the existing countermeasures.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Humans , Hemorrhagic Fever, Crimean/diagnosis , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/prevention & control , Africa , Middle East , Disease Outbreaks
11.
BMC Med ; 21(1): 36, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36726141

ABSTRACT

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) is a widespread disease transmitted to humans and livestock animals through the bite of infected ticks or close contact with infected persons' blood, organs, or other bodily fluids. The virus is responsible for severe viral hemorrhagic fever outbreaks, with a case fatality rate of up to 40%. Despite having the highest fatality rate of the virus, a suitable treatment option or vaccination has not been developed yet. Therefore, this study aimed to formulate a multiepitope vaccine against CCHF through computational vaccine design approaches. METHODS: The glycoprotein, nucleoprotein, and RNA-dependent RNA polymerase of CCHF were utilized to determine immunodominant T- and B-cell epitopes. Subsequently, an integrative computational vaccinology approach was used to formulate a multi-epitopes vaccine candidate against the virus. RESULTS: After rigorous assessment, a multiepitope vaccine was constructed, which was antigenic, immunogenic, and non-allergenic with desired physicochemical properties. Molecular dynamics (MD) simulations of the vaccine-receptor complex show strong stability of the vaccine candidates to the targeted immune receptor. Additionally, the immune simulation of the vaccine candidates found that the vaccine could trigger real-life-like immune responses upon administration to humans. CONCLUSIONS: Finally, we concluded that the formulated multiepitope vaccine candidates would provide excellent prophylactic properties against CCHF.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Viral Vaccines , Humans , Animals , Hemorrhagic Fever, Crimean/prevention & control , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Disease Outbreaks/prevention & control , Vaccination
12.
PLoS Negl Trop Dis ; 17(2): e0011107, 2023 02.
Article in English | MEDLINE | ID: mdl-36730376

ABSTRACT

BACKGROUND: Crimean Congo hemorrhagic fever (CCHF) is a zoonotic tick-borne disease with an increasing number of outbreaks among communities in Uganda. Following the disease outbreak in the western district of Kagadi on 20th February 2020, a KAP survey was conducted to identify knowledge gaps and at-risk behaviors related to the disease among livestock value chain actors. METHODS: A household survey using a semi-structured questionnaire was conducted in 399 households in the two sub counties of Bwikara and Ruteete, Kagadi district. A focus group discussion with members of the community was conducted as well as key informant interviews with at-risk individuals. Descriptive and inferential analysis was performed using STATA version 13 (Statacorp Texas; USA). Comparative analysis of the data from the two sub counties was also performed using cross tabulations in STATA, between each independent variable and the subcounty variable. The descriptive and comparative statistics used were minimum, mean and maximum values, standard deviations, frequencies, percentages, chi square values and t-statistics. A chi-square test was then employed on each tabulation, to determine whether there was an association between the two categorical variables or not. The test was set at an alpha level of 0.05, and where the p-value was less than or equal to the alpha value, we concluded that the 2 variables were associated. RESULTS: Although majority of the respondents believed in the existence of the disease, only 12.8% had knowledge of prevention measures against CCHF. 67.2% of the respondents reported regular interaction with ticks during routine farm operations and they employed tick control measures on their farms. Although the respondents believe the disease is fatal, almost all of them (99%) would welcome a CCHF survivor back into the community. 95.2% of the respondents actively attended to animals but only 25.8% participated in slaughtering animals. Qualitatively, the technical informants had knowledge about CCHF but non technical informants hardly knew about the disease. Limited funding appropriated for local governments, as well as limited engagement in One health activities were some of the barriers highlighted towards the infection prevention and control activities. Most of the focus group discussion participants knew about the disease, but lacked knowledge on its transmission and prevention. Limited access to personal protective equipment and high exposure to tick-prevalent areas when slaughtering and grazing animals respectively, were the major challenges highlighted. CONCLUSION: Knowledge on CCHF among majority of the respondents was poor. There is a need for educational programs to increase awareness of CCHF in communities. This awareness should be done by both the community leaders and technical people to ensure the community receives enough knowledge on how to prevent and control the disease. To ensure effectiveness of these programs a One health approach should be adopted to implement prevention and control strategies.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Ticks , Animals , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/prevention & control , Hemorrhagic Fever, Crimean/veterinary , Livestock , Uganda/epidemiology , Health Knowledge, Attitudes, Practice
13.
Mol Ther ; 31(2): 387-397, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36184852

ABSTRACT

Crimean-Congo hemorrhagic fever virus (CCHFV) is widely distributed throughout Africa, the Middle East, Southern Asia, and Southern and Eastern Europe. Spread by Hyalomma ticks or by contact with infected animals, CCHF begins non-specifically but can rapidly progress to severe, sometimes fatal, disease. Due to the non-specific early symptoms and often unrecognized infections, patients often present to healthcare systems exhibiting later stages of disease, when treatment is limited to supportive care. Consequently, simple vaccines are critically needed to protect populations at risk of CCHFV infection. Currently, there are no widely approved vaccines for CCHFV. We have previously reported significant efficacy of a three-dose DNA-based vaccination regimen for CCHFV in cynomolgus macaques (Macaca fasicularis). Here, we show that in cynomolgus macaques, plasmid-expressed CCHFV nucleoprotein (NP) and glycoprotein precursor (GPC) antigens elicit primarily humoral and cellular immunity, respectively. We found that a two-dose vaccination regimen with plasmids expressing the NP and GPC provides significant protection against CCHFV infection. Studies investigating vaccinations with either antigen alone showed that plasmid-expressed NPs could also confer protection. Cumulatively, our data show that this vaccine confers robust protection against CCHFV and suggest that both humoral and cellular immunity contribute to optimal vaccine-mediated protection.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Vaccines, DNA , Animals , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/prevention & control , Hemorrhagic Fever, Crimean/diagnosis , Macaca , Vaccination
14.
PLoS Negl Trop Dis ; 16(12): e0010988, 2022 12.
Article in English | MEDLINE | ID: mdl-36480553

ABSTRACT

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) continues to pose a serious threat to the fragile healthcare system of Pakistan with a continuous increase of morbidity and mortality. The present study aimed to assess the knowledge, attitudes, and practices regarding CCHF among general people who resided in Pakistan. METHODS: An online cross-sectional survey design was applied, and a convenience sampling technique was used to recruit 1039 adult people from Pakistan. Data were collected from September 08 to October 12, 2021. The questionnaire consisted of a total of 32 questions in four parts assessing socio-demographics, as well as knowledge, attitudes, and practices regarding CCHF. All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS), and logistic regression analyses were performed to determine the factors associated with good knowledge, positive attitudes, and good practices. RESULTS: Alarmingly, 51.5% of participants heard about CCHF infection before administering the survey. Among these, 20.2%, 33.3%, and 48.2% of the study participants had demonstrated good knowledge, positive attitudes, and good practices, respectively. Binary logistic regression analysis revealed that education and income status had a significant impact on knowledge and attitudes (p<0.05). Similarly, the mean attitude scores differed significantly by age, education, and income status (p<0.05). CONCLUSIONS: The findings reflected inadequate levels of knowledge, attitudes, and practices regarding CCHF among general people in Pakistan which may regard as lower than expected. As CCHF is a highly contagious disease, it's urgent to initiate a comprehensive approach to handle the situation before it spreads further in Pakistan.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Adult , Humans , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/prevention & control , Cross-Sectional Studies , Pakistan/epidemiology , Health Knowledge, Attitudes, Practice
15.
Nat Commun ; 13(1): 7298, 2022 11 26.
Article in English | MEDLINE | ID: mdl-36435827

ABSTRACT

Crimean-Congo Hemorrhagic Fever Virus (CCHFV) causes a life-threatening disease with up to a 40% mortality rate. With no approved medical countermeasures, CCHFV is considered a public health priority agent. The non-neutralizing mouse monoclonal antibody (mAb) 13G8 targets CCHFV glycoprotein GP38 and protects mice from lethal CCHFV challenge when administered prophylactically or therapeutically. Here, we reveal the structures of GP38 bound with a human chimeric 13G8 mAb and a newly isolated CC5-17 mAb from a human survivor. These mAbs bind overlapping epitopes with a shifted angle. The broad-spectrum potential of c13G8 and CC5-17 and the practicality of using them against Aigai virus, a closely related nairovirus were examined. Binding studies demonstrate that the presence of non-conserved amino acids in Aigai virus corresponding region prevent CCHFV mAbs from binding Aigai virus GP38. This information, coupled with in vivo efficacy, paves the way for future mAb therapeutics effective against a wide swath of CCHFV strains.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Mice , Humans , Animals , Hemorrhagic Fever Virus, Crimean-Congo/chemistry , Hemorrhagic Fever, Crimean/prevention & control , Antibodies, Neutralizing , Antibodies, Viral , Epitopes , Antibodies, Monoclonal
16.
PLoS Negl Trop Dis ; 16(11): e0010846, 2022 11.
Article in English | MEDLINE | ID: mdl-36395110

ABSTRACT

At a time of major global, societal, and environmental changes, the shifting distribution of pathogen vectors represents a real danger in certain regions of the world as generating opportunities for emergency. For example, the recent arrival of the Hyalomma marginatum ticks in southern France and the concurrent appearance of cases of Crimean-Congo hemorrhagic fever (CCHF)-a disease vectored by this tick species-in neighboring Spain raises many concerns about the associated risks for the European continent. This context has created an urgent need for effective methods for control, surveillance, and risk assessment for ticks and tick-borne diseases with a particular concern regarding Hyalomma sp. Here, we then review the current body of knowledge on different methods of tick control-including chemical, biological, genetical, immunological, and ecological methods-and the latest developments in the field, with a focus on those that have been tested against ticks from the genus Hyalomma. In the absence of a fully and unique efficient approach, we demonstrated that integrated pest management combining several approaches adapted to the local context and species is currently the best strategy for tick control together with a rational use of acaricide. Continued efforts are needed to develop and implement new and innovative methods of tick control.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Ixodidae , Ticks , Animals , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/prevention & control , Hemorrhagic Fever, Crimean/epidemiology , Spain/epidemiology
17.
Vaccine ; 40(40): 5806-5813, 2022 09 22.
Article in English | MEDLINE | ID: mdl-36058795

ABSTRACT

BACKGROUND: Crimean-Congo haemorrhagic fever (CCHF) is a priority emerging pathogen for which a licensed vaccine is not yet available. We aim to assess the feasibility of conducting phase III vaccine efficacy trials and the role of varying transmission dynamics. METHODS: We calibrate models of CCHF virus (CCHFV) transmission among livestock and spillover to humans in endemic areas in Afghanistan, Turkey and South Africa. We propose an individual randomised controlled trial targeted to high-risk population, and use the calibrated models to simulate trial cohorts to estimate the minimum necessary number of cases (trial endpoints) to analyse a vaccine with a minimum efficacy of 60%, under different conditions of sample size and follow-up time in the three selected settings. RESULTS: A mean follow-up of 160,000 person-month (75,000-550,000) would be necessary to accrue the required 150 trial endpoints for a target vaccine efficacy of 60 % and clinically defined endpoint, in a setting like Herat, Afghanistan. For Turkey, the same would be achieved with a mean follow-up of 175,000 person-month (50,000-350,000). The results suggest that for South Africa the low endemic transmission levels will not permit achieving the necessary conditions for conducting this trial within a realistic follow-up time. In the scenario of CCHFV vaccine trial designed to capture infection as opposed to clinical case as a trial endpoint, the required person-months is reduced by 70 % to 80 % in Afghanistan and Turkey, and in South Africa, a trial becomes feasible for a large number of person-months of follow-up (>600,000). Increased expected vaccine efficacy > 60 % will reduce the required number of trial endpoints and thus the sample size and follow-time in phase III trials. CONCLUSIONS: Underlying endemic transmission levels will play a central role in defining the feasibility of phase III vaccine efficacy trials. Endemic settings in Afghanistan and Turkey offer conditions under which such studies could feasibly be conducted.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Vaccines , Animals , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/prevention & control , Humans , Livestock , Vaccine Efficacy
19.
EBioMedicine ; 82: 104188, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35907368

ABSTRACT

BACKGROUND: Crimean-Congo hemorrhagic fever virus is the cause of a severe hemorrhagic fever with cases reported throughout a wide-geographic region. Spread by the bite of infected ticks, contact with infected livestock or in the health care setting, disease begins as a non-specific febrile illness that can rapidly progress to hemorrhagic manifestations. Currently, there are no approved vaccines and antivirals such as ribavirin have unclear efficacy. Thus treatment is mostly limited to supportive care. METHODS: In this report we evaluated an alphavirus-based replicon RNA vaccine expressing either the CCHFV nucleoprotein or glycoprotein precursor in a stringent, heterologous lethal challenge mouse model. FINDINGS: Vaccination with the RNA expressing the nucleoprotein alone could confer complete protection against clinical disease, but vaccination with a combination of both the nucleoprotein and glycoprotein precursor afforded robust protection against disease and viral replication. Protection from lethal challenge required as little as a single immunization with 100ng of RNA. Unexpectedly, analysis of the immune responses elicited by the vaccine components showed that vaccination resulted in antibodies against the internal viral nucleoprotein and cellular immunity against the virion-exposed glycoproteins. INTERPRETATION: Cumulatively this vaccine conferred robust protection against Crimean-Congo hemorrhagic fever virus and supports continued development of this vaccine candidate. FUNDING: This research was supported by the Intramural Research Program of the NIAID/NIH and HDT Bio.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Animals , Antibodies, Viral , Glycoproteins , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/prevention & control , Immunity , Mice , Mice, Knockout , Nucleoproteins , RNA , Vaccination , Vaccines, Synthetic , mRNA Vaccines
20.
Microb Pathog ; 169: 105657, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35753597

ABSTRACT

The Crimean Congo Hemorrhagic Fever Virus (CCHFV) is widespread in Africa, Asia, and Europe, among other places. The disease was initially discovered in the Crimean cities of the Soviet Union and the Congo, and it was given the name Crimean Congo because it induces hemorrhagic fever. According to studies, when the virus enters the body, it settles in immune cells such as macrophages and dendritic cells, causing them to malfunction and secrete inflammatory cytokines such as TNF-alpha, IL1, and IL6, resulting in cytokine storms that induces shock via endothelial activation and vascular leakage, while on the other hand, clots and disseminated intravascular coagulation (DIC) formation causes massive defects in various organs such as the liver and kidneys, as well as fatal bleeding. Disease prevention and treatment are crucial since no other effective vaccination against the disease has yet been developed. Immunotherapy is utilized as a consequence. One of the most effective treatments, when combined with compensatory therapies such as blood and platelet replacement, water, electrolytes, Fresh Frozen Plasma (FFP) replacement, and other compensatory therapies, is one of the most effective treatments. Studies; show that immunotherapy using IVIG and neutralizing and non-neutralizing monoclonal antibodies; cytokine therapy, and anti-inflammatory therapy using corticosteroids are effective ways to treat the disease.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Cytokines , Hemorrhagic Fever, Crimean/prevention & control , Humans , Liver , Tumor Necrosis Factor-alpha
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