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  1. Abstract. After failed attempts at producing bacteria-based vaccines, the discovery of a viral agent causing yellow fever and its isolation in monkeys opened new avenues of research. Subsequent advances were the attenuation of the virus in mice and later in tissue culture; the creation of the seed lot system to avoid spontaneous mutations; the ...

    • Frierson Jg
    • 2010
  2. Yellow fever vaccine is a live vaccine containing weakened, live yellow fever virus. It is given as a single shot. One dose provides lifelong protection for most people. Yellow fever vaccine is recommended for: People 9 months through 59 years of age who are traveling to or living in areas at risk for yellow fever virus activity, or traveling ...

  3. Yellow fever virus has three transmission cycles: jungle (sylvatic), inter­mediate (savannah), and urban. The jungle (sylvatic) cycle involves transmission of the virus between non-human primates (e.g., monkeys) and mosquito species found in the forest canopy.

    • Overview
    • Acknowledgments

    Malini DeSilva, MD1, Arun Sharma, MD2, Erin Staples, MD3, Byron Arndt, MD4, Wun-Ju Shieh, MD5, Jim Shames, MD6, Paul Cieslak, MD7 (Author affiliations at end of text)

    In September 2014, a previously healthy Oregon woman in her 60s went to a hospital emergency department with malaise, dyspnea, vomiting, and diarrhea of 3–5 days' duration. She reported no recent travel, ill contacts, or dietary changes. Six days earlier, she had received a single dose of yellow fever vaccine and typhoid vaccine before planned travel to South America.

    In the emergency department, the woman was afebrile but tachycardic and weak. Initial laboratory reports included a white blood cell count of 4,400/µL (reference range [RR] = 4,800–10,800/µL), platelet count of 84,000/µL (RR = 150,000–400,000/µL), potassium level of 2.8 mmol/L (RR = 3.5–5.1 mmol/L), and calcium level of 8.0 mg/dL (RR = 8.6–10.0 mg/dL). She was admitted to the hospital with diagnoses of gastroenteritis, malaise, dyspnea, and thrombocytopenia. Within 10 hours of admission, she experienced acute respiratory failure requiring intubation and mechanical ventilation. Contrast chest computed tomography indicated a substantial mediastinal mass. The patient experienced cardiogenic shock and acute renal failure and died 3 days after admission. At autopsy, the thymus was diffusely enlarged, consistent with thymoma. The concentration of acetylcholine receptor binding antibody in blood collected 1 day before death was 0.88 nmol/L (RR = ≤0.02 nmol/L), indicative of myasthenia gravis.

    Tissue and serum samples were tested at CDC for evidence of yellow fever vaccine–associated viscerotropic disease (YEL-AVD), a serious adverse reaction resulting from the uncontrolled replication of vaccine virus and characterized by multisystem organ dysfunction; 60% of reported cases are fatal (1). Immunohistochemical staining indicated yellow fever virus antigen in tissue samples from various organs (Figure). Reverse transcription–polymerase chain reaction detected yellow fever vaccine viral RNA in multiple organs and in a serum sample that had been collected 2 days before death. Additionally, a serum sample obtained 1 day before death demonstrated evidence of yellow fever immunoglobulin M, with a yellow fever virus–specific neutralizing antibody titer of 640. Testing of yellow fever viral RNA from the vaccine lot used to vaccinate the woman identified sequences consistent with known vaccine strains without any notable mutations.

    The patient's clinical course and laboratory results, including her requirement for mechanical ventilation, platelets <100,000/µL, hypotension requiring vasopressor drugs to maintain systolic blood pressure, and increase in creatinine to ≥1.5 times the upper limit of normal, met Level 1 diagnostic certainty for viscerotropic disease. The temporal relationship between yellow fever vaccination and development of symptoms was consistent with YEL-AVD (1). The presence of yellow fever virus–specific antigen in multiple organs demonstrated by immunohistochemistry, in addition to amplification of yellow fever 17D viral RNA from tissue, met criteria for definite yellow fever vaccine–associated causality (1). Both her age at vaccination and occult thymic disease likely predisposed this patient to YEL-AVD development.

    The risk for YEL-AVD in the United States is approximately 0.4 cases per 100,000 doses of yellow fever vaccine distributed; older age and thymic disease have been associated with an increased risk for YEL-AVD (2). Risk increases to one case per 100,000 doses of yellow fever vaccine distributed for travelers aged ≥60 years and 2.3 cases per 100,000 doses for those aged ≥70 years (3). Of the first 23 YEL-AVD cases described, four (17%) were in patients who had a history of thymoma (4). Risk related to thymic disease might persist even after thymus resection (4). The incidence of thymoma in the United States is approximately 0.13 per 100,000 person-years, increasing with age and peaking among persons aged ≥60 years. Approximately one third of thymomas are diagnosed among asymptomatic patients on the basis of abnormal chest radiographs or computed tomography (5); 10%–20% of patients with myasthenia gravis have a thymoma, and approximately 30% of patients with thymoma have thymoma-associated myasthenia gravis (6).

    Robert Lanciotti, Amanda Panella, Olga Kosoy, Jason Velez, Marc Fischer, Arboviral Diseases Branch, Division of Vector-Borne Diseases, CDC.

  4. Nov 18, 2022 · Overview . The Country List is a compilation of key information to facilitate international travel. The information provided for each country includes vaccination requirements for international travellers as provided by States Parties to the International Health Regulations (2005) (IHR), as well as WHO recommendations for vaccination against yellow fever, poliomielytis, and malaria prophylaxis.

  5. Country requirement: a yellow fever vaccination certificate is required for travellers over 1 year of age arriving from countries with risk of yellow fever transmission. Malaria (2013): Malaria risk – P. falciparum (40%), P. vivax (58%), mixed infections 2% – continues to decrease in recent years.

  6. Oct 12, 2016 · Because viscerotropic disease has a highly predictable pathologic course, it is likely that viscerotropic disease post-YF vaccine occurs in low-income countries with the same incidence as in developing countries. YF vaccine is a very safe vaccine that likely confers lifelong immunity. Keywords: yellow fever vaccine, viscerotropic disease ...

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