ANTIBODY TITER ASSESSMENT BY IMAGE CYTOMETRY

"In order to prevent the spread of viral infections or to assess the effectiveness of vaccination, there is an urgent need for methods to quickly identify and characterize possible treatment options. The serological methods, commonly used for antibody titration, are informative yet the data provided are sometimes limited. Imaging cytometry can be an effective approach for characterizing potential therapeutic antibodies to combat viral infections. Using an indirect immunofluorescence test, based on BIOCHIP technology to detect anti-yellow fever virus IgG, we realized a calibration curve based on dilution of a positive control serum and a blood sample obtained from a person who has received the yellow fever vaccine. The obtained images were then analysed by image cytometry which involved: image pre-processing, removal of the cell nucleus considered to be the most representative for measurement, indirect measurement of five times the specific corrected total cellular fluorescence (CTCF) for each representative cell and calculation of the average CTCF value. We calculated the mean CTCF values for each condition and correlated the CTCF value with the antibody titer, according to the manufacturer's recommendations. Image cytometry has the ability to rapidly determine the direct binding of antibodies to host cells and can be applied to study other pathogen-antibody interactions, thus impacting future research on viral pathogens. "

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Cutaneous lesions caused by the yellow fever vaccine – have you ever seen them?

Revista da Associação Médica Brasileira ◽

10.1590/1806-9282.64.06.498 ◽

2018 ◽

Vol 64 (6) ◽

pp. 498-500 ◽

Cited By ~ 2

Author(s):

Michelle Larissa Zini Lise ◽

Michael Laurence Zini Lise

Keyword(s):

Side Effects ◽

South America ◽

Skin Rash ◽

Yellow Fever ◽

Yellow Fever Virus ◽

Fever Virus ◽

Yellow Fever Vaccine ◽

Cutaneous Lesions ◽

Tropical Regions

SUMMARY The Yellow Fever virus was isolated in 1927 and the disease is considered endemic and epidemic in tropical regions of South America and Africa, with thousands of new cases reported annually. Several side effects of the vaccine have already been reported. Although reports of skin rash secondary to the vaccine range from 0 to 15%, no image or detailed description of the lesions were found in the literature. Here we describe a rash on a toddler vaccinated to travel.

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Prescrição da Vacina Contra a Febre Amarela: Experiência do Centro de Vacinação Internacional do Agrupamento de Centros de Saúde Loures-Odivela

Acta Médica Portuguesa ◽

10.20344/amp.10309 ◽

2018 ◽

Vol 31 (12) ◽

pp. 724

Author(s):

Clarisse Martinho ◽

David Lopes ◽

Luciana Bastos ◽

Hugo Esteves

Keyword(s):

Yellow Fever ◽

Yellow Fever Virus ◽

Health Centre ◽

Travel Medicine ◽

Sub Saharan Africa ◽

World Health ◽

Yellow Fever Vaccine ◽

Travel Destination ◽

Vector Borne ◽

Sub Saharan

Introduction: Yellow fever is a vector-borne disease in sub-Saharan Africa and tropical South America regions which is preventable by an effective and safe vaccine. In some cases, it may cause serious adverse effects and should therefore be prescribed only to individuals at risk of exposure to the yellow fever virus or those traveling to countries requiring proof of vaccination. The aim of this study was to analyze the prescriptions of yellow fever vaccine, based on travel destination and type of referring consultation, according to the international recommendations of the World Health Organization.Material and Methods: The database of the International Vaccination Centre of the International Vaccination Centre of the Loures-Odivelas Health Centre Group was used to analyze data concerning the year of 2016. Travelers who were prescribed and administered the yellow fever vaccine were grouped based on travel destination and type of referring consultation (travelers’ medical consultations or non-specialist consultations).Results: A total of 517 yellow fever vaccines were administered, with the highest proportion in female (53%) and in individuals aged 40 - 49 years (20.7%). One hundred and thirteen (22.6%) of the 499 individuals with known-destinations were travelling to non-endemic/non-epidemic countries and a greater proportion of those were prescribed in non-specialist consultations (27.3%) than in travel medicine consultations (8.8%).Discussion/Conclusion: The highest percentage of yellow fever vaccines that were administered to individuals travelling to non-endemic/non-epidemic countries were prescribed in non-specialist consultations.

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A yellow fever vaccine free from avian leucosis viruses

Epidemiology and Infection ◽

10.1017/s0022172400046040 ◽

1967 ◽

Vol 65 (4) ◽

pp. 505-513 ◽

Cited By ~ 8

Author(s):

C. C. Draper

Keyword(s):

Yellow Fever ◽

Yellow Fever Virus ◽

Human Subjects ◽

Fever Virus ◽

Yellow Fever Vaccine

1. The methods used for clearing a vaccine substrain of 17 D yellow fever virus of contaminant avian leucosis viruses are described.2. Tests in animals and human subjects showed that the characteristics of the virus remained unchanged.

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Herpes Infections in Suspected Cases of Yellow Fever in the Democratic Republic of the Congo

Medicina ◽

10.3390/medicina57090871 ◽

2021 ◽

Vol 57 (9) ◽

pp. 871

Author(s):

Sheila Makiala-Mandanda ◽

Jessica L. Abbate ◽

Elisabeth Pukuta-Simbu ◽

Steve Ahuka-Mundeke ◽

Jean-Jacques Muyembe-Tamfum ◽

...

Keyword(s):

Yellow Fever ◽

Democratic Republic ◽

Viral Infections ◽

Yellow Fever Virus ◽

Surveillance Program ◽

Human Herpes ◽

Varicella Zoster ◽

Real Time Quantitative Pcr ◽

Republic Of The Congo ◽

Febrile Jaundice

In the battle to quickly identify potential yellow fever arbovirus outbreaks in the Democratic Republic of the Congo, active syndromic surveillance of acute febrile jaundice patients across the country is a powerful tool. However, patients who test negative for yellow fever virus infection are too often left without a diagnosis. By retroactively screening samples for other potential viral infections, we can both try to find sources of patient disease and gain information on how commonly they may occur and co-occur. Several human arboviruses have previously been identified, but there remain many other viral families that could be responsible for acute febrile jaundice. Here, we assessed the prevalence of human herpes viruses (HHVs) in these acute febrile jaundice disease samples. Total viral DNA was extracted from serum of 451 patients with acute febrile jaundice. We used real-time quantitative PCR to test all specimens for cytomegalovirus (CMV), herpes simplex virus (HSV), human herpes virus type 6 (HHV-6) and varicella-zoster virus (VZV). We found 21.3% had active HHV replication (13.1%, 2.4%, 6.2% and 2.4% were positive for CMV, HSV, HHV-6 and VZV, respectively), and that nearly half (45.8%) of these infections were characterized by co-infection either among HHVs or between HHVs and other viral infection, sometimes associated with acute febrile jaundice previously identified. Our results show that the role of HHV primary infection or reactivation in contributing to acute febrile jaundice disease identified through the yellow fever surveillance program should be routinely considered in diagnosing these patients.

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Experience of application of IgY-technology for laboratory diagnostics of viral infections

Voprosy Virusologii ◽

10.36233/0507-4088-2020-65-1-21-26 ◽

2020 ◽

Vol 65 (1) ◽

pp. 21-26 ◽

Cited By ~ 2

Author(s):

A. P. Ivanov ◽

T. D. Klebleeva ◽

O. E. Ivanova

Keyword(s):

Yellow Fever ◽

Viral Infections ◽

Yellow Fever Virus ◽

Laboratory Diagnosis ◽

Encephalitis Virus ◽

Fever Virus ◽

Laboratory Animals ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus

Introduction. The well-known advantages of class Y antibodies (IgY) from egg yolks of immunized hens in comparison with class G antibodies (IgG) of laboratory animals traditionally used in laboratory diagnosis of infectious diseases determine the stable interest of researchers in using IgY for these purposes (IgY technology) . Over the past 20 years, the obvious benefits of IgY technology have been demonstrated for a number of viral and bacterial infections. Goals and objectives. Construction of ELISA systems based on specific IgY for laboratory diagnosis of infections caused by tick-borne encephalitis virus, yellow fever virus, poliovirus.Material and methods. Obtaining yolk preparations of immunized chickens, obtaining highly purified IgY preparations (salting out, affinity chromatography), constructing ELISA systems for determining virus-specific antigens, testing the parameters of ELISA systems.Results and discussion. For the first time in laboratory practice, ELISA systems based on the use of specific polyclonal IgY were designed for laboratory diagnosis of topical human viral infections caused by flaviviruses and enteroviruses: determination of antigens of tick-borne encephalitis virus, yellow fever virus, 3 types of poliovirus. It was experimentally shown that these ELISA systems have high sensitivity and specificity, which allows them to be used for the semiquantitative and quantitative determination of antigens of these viruses in various materials (infected cell cultures, vaccines, etc.).Conclusion. The ELISA systems developed on the basis of specific IgY for determination of viral antigens can be effectively used for laboratory diagnosis of a number of viral infections, for the validation and control of vaccine preparations.

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Antibacterial, Antifungal, Antiviral, and Anthelmintic Activities of Medicinal Plants of Nepal Selected Based on Ethnobotanical Evidence

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2020/1043471 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Bishnu Joshi ◽

Sujogya Kumar Panda ◽

Ramin Saleh Jouneghani ◽

Maoxuan Liu ◽

Niranjan Parajuli ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Medicinal Plants ◽

Yellow Fever ◽

Yellow Fever Virus ◽

Treatment Options ◽

Fungal Species ◽

C Elegans ◽

Methanolic Extracts ◽

Kalanchoe Pinnata ◽

Bacteria And Fungi

Background. Infections by microbes (viruses, bacteria, and fungi) and parasites can cause serious diseases in both humans and animals. Heavy use of antimicrobials has created selective pressure and caused resistance to currently available antibiotics, hence the need for finding new and better antibiotics. Natural products, especially from plants, are known for their medicinal properties, including antimicrobial and anthelmintic activities. Geoclimatic variation, together with diversity in ethnomedicinal traditions, has made the Himalayas of Nepal an invaluable repository of traditional medicinal plants. We studied antiviral, antibacterial, antifungal, and anthelmintic activities of medicinal plants, selected based upon ethnobotanical evidence. Methods. Ethanolic and methanolic extracts were tested (1) on a panel of microbes: two Gram-positive bacteria (Staphylococcus aureus and Listeria innocua), four Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, and Shigella sonnei), and one fungal species: Candida albicans; (2) against three different viruses: yellow fever, chikungunya, and enterovirus; and (3) on the nematode Caenorhabditis elegans. Also, cytotoxicity was assessed on human hepatoma (Huh), rhabdosarcoma (RD), and Vero (VC) cell lines. Results. Of 18 plants studied, Ampelocissus tomentosa and Aleuritopteris anceps inhibited S. aureus (MIC 35 μg/mL and 649 μg/mL, respectively) and Pseudomonas aeruginosa (MIC 15 μg/mL and 38 μg/mL, respectively). Rhododendron arboreum and Adhatoda vasica inhibited S. enterica (MIC 285 μg/mL and 326 μg/mL, respectively). Kalanchoe pinnata, Ampelocissus tomentosa, and Paris polyphylla were active against chikungunya virus, and Clerodendrum serratum was active against yellow fever virus (EC50 15.9 μg/mL); Terminalia chebula was active against enterovirus (EC50 10.6 μg/mL). Ampelocissus tomentosa, Boenninghausenia albiflora, Dichrocephala integrifolia, and Kalanchoe pinnata significantly reduced C. elegans motility, comparable to levamisole. Conclusions. In countries like Nepal, with a high burden of infectious and parasitic diseases, and a current health system unable to combat the burden of diseases, evaluation of local plants as a treatment or potential source of drugs can help expand treatment options. Screening plants against a broad range of pathogens (bacteria, viruses, fungi, and parasites) will support bioprospecting in Nepal, which may eventually lead to new drug development.

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Vaccine and Wild-Type Strains of Yellow Fever Virus Engage Distinct Entry Mechanisms and Differentially Stimulate Antiviral Immune Responses

mBio ◽

10.1128/mbio.01956-15 ◽

2016 ◽

Vol 7 (1) ◽

Cited By ~ 32

Author(s):

Maria Dolores Fernandez-Garcia ◽

Laurent Meertens ◽

Maxime Chazal ◽

Mohamed Lamine Hafirassou ◽

Ophélie Dejarnac ◽

...

Keyword(s):

Yellow Fever ◽

Yellow Fever Virus ◽

Virus Entry ◽

Fever Virus ◽

Host Cells ◽

Target Cells ◽

Wild Type ◽

E Protein ◽

Virulence Attenuation ◽

Molecular Determinants

ABSTRACTThe live attenuated yellow fever virus (YFV) vaccine 17D stands as a “gold standard” for a successful vaccine. 17D was developed empirically by passaging the wild-type Asibi strain in mouse and chicken embryo tissues. Despite its immense success, the molecular determinants for virulence attenuation and immunogenicity of the 17D vaccine are poorly understood. 17D evolved several mutations in its genome, most of which lie within the envelope (E) protein. Given the major role played by the YFV E protein during virus entry, it has been hypothesized that the residues that diverge between the Asibi and 17D E proteins may be key determinants of attenuation. In this study, we define the process of YFV entry into target cells and investigate its implication in the activation of the antiviral cytokine response. We found that Asibi infects host cells exclusively via the classical clathrin-mediated endocytosis, while 17D exploits a clathrin-independent pathway for infectious entry. We demonstrate that the mutations in the 17D E protein acquired during the attenuation process are sufficient to explain the differential entry of Asibi versus 17D. Interestingly, we show that 17D binds to and infects host cells more efficiently than Asibi, which culminates in increased delivery of viral RNA into the cytosol and robust activation of the cytokine-mediated antiviral response. Overall, our study reveals that 17D vaccine and Asibi enter target cells through distinct mechanisms and highlights a link between 17D attenuation, virus entry, and immune activation.IMPORTANCEThe yellow fever virus (YFV) vaccine 17D is one of the safest and most effective live virus vaccines ever developed. The molecular determinants for virulence attenuation and immunogenicity of 17D are poorly understood. 17D was generated by serially passaging the virulent Asibi strain in vertebrate tissues. Here we examined the entry mechanisms engaged by YFV Asibi and the 17D vaccine. We found the two viruses use different entry pathways. We show that the mutations differentiating the Asibi envelope (E) protein from the 17D E protein, which arose during attenuation, are key determinants for the use of these distinct entry routes. Finally, we demonstrate that 17D binds and enters host cells more efficiently than Asibi. This results in a higher uptake of viral RNA into the cytoplasm and consequently a greater cytokine-mediated antiviral response. Overall, our data provide new insights into the biology of YFV infection and the mechanisms of viral attenuation.

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Yellow Fever Virus Exhibits Slower Evolutionary Dynamics than Dengue Virus

Journal of Virology ◽

10.1128/jvi.01738-09 ◽

2009 ◽

Vol 84 (2) ◽

pp. 765-772 ◽

Cited By ~ 46

Author(s):

Amadou A. Sall ◽

Ousmane Faye ◽

Mawlouth Diallo ◽

Cadhla Firth ◽

Andrew Kitchen ◽

...

Keyword(s):

Dengue Virus ◽

Yellow Fever ◽

Central African Republic ◽

Evolutionary Dynamics ◽

Nucleotide Substitution ◽

Viral Infections ◽

Yellow Fever Virus ◽

Fever Virus ◽

Limited Information ◽

Reduced Rate

ABSTRACT Although yellow fever has historically been one of the most important viral infections of humans, relatively little is known about the evolutionary processes that shape its genetic diversity. Similarly, there is limited information on the molecular epidemiology of yellow fever virus (YFV) in Africa even though it most likely first emerged on this continent. Through an analysis of complete E gene sequences, including a newly acquired viral collection from Central and West Africa (Senegal, Cameroon, Central African Republic, Côte d'Ivoire, Mali, and Mauritania), we show that YFV exhibits markedly lower rates of evolutionary change than dengue virus, despite numerous biological similarities between these two viruses. From this observation, along with a lack of clock-like evolutionary behavior in YFV, we suggest that vertical transmission, itself characterized by lower replication rates, may play an important role in the evolution of YFV in its enzootic setting. Despite a reduced rate of nucleotide substitution, phylogenetic patterns and estimates of times to common ancestry in YFV still accord well with the dual histories of colonialism and the slave trade, with areas of sylvatic transmission (such as Kedougou, Senegal) acting as enzootic/epidemic foci.

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Restricted replication and lysosomal trafficking of yellow fever 17D vaccine virus in human dendritic cells

Journal of General Virology ◽

10.1099/vir.0.82272-0 ◽

2007 ◽

Vol 88 (1) ◽

pp. 148-156 ◽

Cited By ~ 28

Author(s):

Dupeh R. Palmer ◽

Stefan Fernandez ◽

John Bisbing ◽

Kristina K. Peachman ◽

Mangala Rao ◽

...

Keyword(s):

Dendritic Cells ◽

Immune Responses ◽

Yellow Fever ◽

Virus Replication ◽

Yellow Fever Virus ◽

Vaccine Virus ◽

Yellow Fever Vaccine ◽

Effective Vaccine ◽

Contributing Factors

The yellow fever virus attenuated 17D vaccine strain is a safe and effective vaccine and a valuable model system for evaluating immune responses against attenuated viral variants. This study compared the in vitro interactions of the commercially available yellow fever vaccine (YF-VAX), Dengue virus and the live-attenuated dengue vaccine PDK50 with dendritic cells (DCs), the main antigen-presenting cells at the initiation of immune responses. Similar to PDK50, infection with YF-VAX generated activated DCs; however, for YF-VAX, activation occurred with limited intracellular virus replication. The majority of internalized virus co-localized with endolysosomal markers within 90 min, suggesting that YF-VAX is processed rapidly in DCs. These results indicate that restricted virus replication and lysosomal compartmentalization may be important contributing factors to the success of the YF-VAX vaccine.

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Treatment of Yellow Fever Virus with an Adenovirus-Vectored Interferon, DEF201, in a Hamster Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01635-10 ◽

2011 ◽

Vol 55 (5) ◽

pp. 2067-2073 ◽

Cited By ~ 35

Author(s):

Justin G. Julander ◽

Jane Ennis ◽

Jeffrey Turner ◽

John D. Morrey

Keyword(s):

Yellow Fever ◽

Viral Infections ◽

Yellow Fever Virus ◽

Adenovirus Type ◽

Fever Virus ◽

Hamster Model ◽

Virus Challenge ◽

Infection Treatment ◽

Effective Prophylaxis ◽

Adenovirus Type 5

ABSTRACTInterferon (IFN) is an innate immune response protein that is involved in the antiviral response during viral infection. Treatment of acute viral infections with exogenous interferon may be effective but is generally not feasible for clinical use due to many factors, including cost, stability, and availability. To overcome these limitations, an adenovirus type 5-vectored consensus alpha IFN, termed DEF201, was constructed as a potential way to deliver sustained therapeutic levels of systemic IFN. To demonstrate the efficacy of DEF201 against acute flaviviral disease, various concentrations of the construct were administered as a single intranasal dose prior to virus infection, which resulted in a dose-responsive, protective effect in a hamster model of yellow fever virus (YFV) disease. A DEF201 dose of 5 × 107PFU/animal administered intranasally just prior to YFV challenge protected 100% of the animals, while a 10-fold lower DEF201 dose exhibited lower, although significant, levels of protection. Virus titers in the liver and serum and levels of serum alanine aminotransferase were all significantly reduced as a result of DEF201 administration at all doses tested. No toxicity, as indicated by weight loss or gross morbidity, was observed in non-YFV-infected animals treated with DEF201. Protection of YFV-infected animals was observed when DEF201 was delivered as early as 7 days prior to virus challenge and as late as 2 days after virus challenge, demonstrating effective prophylaxis and therapy in a hamster model of disease. Overall, it appears that DEF201 is effective in the treatment of YFV in a hamster model.

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