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Yellow Fever: Global Impact, Epidemiology, Pathogenesis, and Integrated Prevention Approaches.

Yellow fever poses a substantial global health concern as one of the re-emerging diseases with pandemic potential in a scenario of the worldwide distribution of some vectors (such as Aedes aegypti); in the context of climatic change, an unclear knowledge about the immune behaviour of the virus, between other determinants. This review details the historical foundations, intricate evolution of geographical spread, and transmission mechanisms of the disease to understand the behaviour of outbreaks over time in a multifactorial context that could be difficult to understand. This article approaches…

A clinician's perspective on yellow fever vaccine-associated neurotropic disease.

Yellow fever (YF) causes high fever, liver dysfunction, renal failure, hypercoagulopathy and platelet dysfunction and can lead to shock and death with a case-fatality ratio of 20-50%. YF vaccination results in long-lasting protective immunity. Serious adverse events (SAEs), such as YF vaccine-associated neurotropic disease (YEL-AND) are rare. We present a case of a 56-year-old Caucasian man with fever, headache, cognitive problems at the emergency department. He received a primary YF vaccination 4 weeks prior to symptom onset. Cerebrospinal fluid tested positive (POS) for YF virus by reverse t…

Invasive aspergillosis complication in yellow fever vaccine induced viscerotropic disease.

Invasive aspergillosis (IA) usually occurs in immunocompromised hosts, but in the last decade IA has emerged in critically ill non-neutropenic patients, as those with severe Influenza and Chronic Obstructive Pulmonary Disease (COPD). We report an unusual fatal case of disseminated IA in a non-immunocompromised patient following yellow fever vaccine-associated viscerotropic disease.

Genomic and epidemiological monitoring of yellow fever virus transmission potential.

The yellow fever virus (YFV) epidemic in Brazil is the largest in decades. The recent discovery of YFV in Brazilian Aedes species mosquitos highlights a need to monitor the risk of reestablishment of urban YFV transmission in the Americas. We use a suite of epidemiological, spatial, and genomic approaches to characterize YFV transmission. We show that the age and sex distribution of human cases is characteristic of sylvatic transmission. Analysis of YFV cases combined with genomes generated locally reveals an early phase of sylvatic YFV transmission and spatial expansion toward previously YFV-…

Филогеномический анализ раскрывает эволюцию вируса желтой лихорадки внутри хостов.

Вирус желтой лихорадки (YFV) недавно появился во время крупных вспышек в Африке и Бразилии, и первые импортированные в Азию пациенты напомнили о проблемах эволюции YFV. Здесь мы показываем филогеномию YFV с серийными клиническими образцами инфекций YFV 2016 года. Филогенетика показала, что штаммы 2016 года были близки к штамму в Анголе 1971 года и только три аминокислотные изменения были новыми для других линий. Глубокая последовательность вирусных геномов выявила 101 внутреннюю вариацию одного нуклеотида (ISNV) и 234 единичные нуклеотидные полиморфизмы (SNPs). Анализ распределения ИСНВ и мути

Совпадение в аннотации оригинала
The yellow fever virus (YFV) recently reemerged in the large outbreaks in Africa and Brazil, and the first imported patients into Asia have recalled the concerns of YFV evolution. Here we show phylogenomics of YFV with serial clinical samples of the 2016 YFV infections. Phylogenetics exhibited that the 2016 strains were close to Angola 1971 strains and only …

Yellow fever vaccination for Chilean tourists visiting Brazil. Practical considerations.

Due to the recent yellow fever outbreak affecting the costal region of Brazil, including main touristic destinations, there is a high demand of yellow fever vaccination. This publication addresses the most relevant practical issues regarding this vaccine for tourists visiting Brazil and aims to serve as a guideline for non-expert physicians in Chile and elsewhere.

What Does the Future Hold for Yellow Fever Virus? (I).

The recent resurgence of yellow fever virus (YFV) activity in the tropical regions of Africa and South America has sparked renewed interest in this infamous arboviral disease. Yellow fever virus had been a human plague for centuries prior to the identification of its urban transmission vector, the Aedes (Stegomyia) aegypti (Linnaeus) mosquito species, and the development of an efficient live-attenuated vaccine, the YF-17D strain. The combination of vector-control measures and vaccination campaigns drastically reduced YFV incidence in humans on many occasions, but the virus never ceased to circ…

Addressing a Yellow Fever Vaccine Shortage - United States, 2016-2017.

Recent manufacturing problems resulted in a shortage of the only U.S.-licensed yellow fever vaccine. This shortage is expected to lead to a complete depletion of yellow fever vaccine available for the immunization of U.S. travelers by mid-2017. CDC, the Food and Drug Administration (FDA), and Sanofi Pasteur are collaborating to ensure a continuous yellow fever vaccine supply in the United States. As part of this collaboration, Sanofi Pasteur submitted an expanded access investigational new drug (eIND) application to FDA in September 2016 to allow for the importation and use of an alternative y…

Early molecular correlates of adverse events following yellow fever vaccination.

The innate immune response shapes the development of adaptive immunity following infections and vaccination. However, it can also induce symptoms such as fever and myalgia, leading to the possibility that the molecular basis of immunogenicity and reactogenicity of vaccination are inseparably linked. To test this possibility, we used the yellow fever live-attenuated vaccine (YFLAV) as a model to study the molecular correlates of reactogenicity or adverse events (AEs). We analyzed the outcome of 68 adults who completed a YFLAV clinical trial, of which 43 (63.2%) reported systemic AEs. Through wh…

Protective and immunological behavior of chimeric yellow fever dengue vaccine.

Clinical observations from the third year of the Sanofi Pasteur chimeric yellow fever dengue tetravalent vaccine (CYD) trials document both protection and vaccination-enhanced dengue disease among vaccine recipients. Children who were 5 years-old or younger when vaccinated experienced a DENV disease resulting in hospitalization at 5 times the rate of controls. On closer inspection, hospitalized cases among vaccinated seropositives, those at highest risk to hospitalized disease accompanying a dengue virus (DENV) infection, were greatly reduced by vaccination. But, seronegative individuals of al…

A DNA vaccine against yellow fever virus: development and evaluation.

Attenuated yellow fever (YF) virus 17D/17DD vaccines are the only available protection from YF infection, which remains a significant source of morbidity and mortality in the tropical areas of the world. The attenuated YF virus vaccine, which is used worldwide, generates both long-lasting neutralizing antibodies and strong T-cell responses. However, on rare occasions, this vaccine has toxic side effects that can be fatal. This study presents the design of two non-viral DNA-based antigen formulations and the characterization of their expression and immunological properties. The two antigen form…

Duration of post-vaccination immunity against yellow fever in adults.

INTRODUCTION: Available scientific evidence to recommend or to advise against booster doses of yellow fever vaccine (YFV) is inconclusive. A study to estimate the seropositivity rate and geometric mean titres (GMT) of adults with varied times of vaccination was aimed to provide elements to revise the need and the timing of revaccination. METHODS: Adults from the cities of Rio de Janeiro and Alfenas located in non-endemic areas in the Southeast of Brazil, who had one dose of YFV, were tested for YF neutralising antibodies and dengue IgG. Time (in years) since vaccination was based on immunisat…

Vaccine administration decision making: the case of yellow fever vaccine.

BACKGROUND: Providers must counsel travelers to yellow fever (YF)-endemic areas, although risk estimates of disease and vaccine serious adverse events (SAEs) may be imprecise. The impact of risk information and patients' requests for participation in vaccine decisions on providers' recommendations is unknown. METHODS: Vaccine providers were surveyed regarding decisions for 4 patient scenarios before and after being presented information about risk of YF disease vs vaccine SAEs. Participants' theoretical attitudes were compared with actual responses to scenarios in which patients wanted to sha…

Transfusion-related transmission of yellow fever vaccine virus--California, 2009.

In the United States, yellow fever (YF) vaccination is recommended for travelers and active duty military members visiting endemic areas of sub-Saharan Africa and Central/South America. The American Red Cross recommends that recipients of YF vaccine defer blood product donation for 2 weeks because of the theoretical risk for transmission from a viremic donor. On April 10, 2009, a hospital blood bank supervisor learned that, on March 27, blood products had been collected from 89 U.S. active duty trainees who had received YF vaccine 4 days before donation. This report summarizes the subsequent i…

[Should yellow fever vaccination be recommended during pregnancy or breastfeeding?].

Yellow fever vaccine is produced from a live attenuated virus that is contraindicated in case of immunodeficiency and subject to restrictions for pregnant or breastfeeding women. The purpose of this review of available information on yellow fever vaccination during pregnancy and breastfeeding is to assist physicians in making recommendations prior to departure to yellow-fever endemic zones. Regarding pregnancy, there is no evidence to support a major risk of yellow-fever-vaccine-related complications in mothers or children. Although this finding is reassuring, it should be underlined that most…