Safety Of Yellow Fever Vaccine Research Articles

Yellow Fever immunization: an integrative review on vacinal security / Imunização contra Febre Amarela: uma revisão integrativa sobre segurança vacinal

Introduction: Yellow fever (YF) is an acute, febrile, non-contagious infectious disease caused by arboviruses. Clinically, YF ranges from asymptomatic to malignant forms. The disease is transmitted by the bite of the female hematophagous arthropods of the Culicidae family. The main form of prevention of YF is vaccination. In this bias, some conditions determine the highest incidence of adverse effects of vaccination, such as: primary vaccination in people over 60 years of age, vaccination of patients with immunosuppressive diseases or hematological diseases. Adverse effects are also related to the techniques used, material used and patient guidance. Materials and methods: The databases used were Lilacs and Scielo to review the national and indexed literature about safety of yellow fever vaccine. The descriptors were: “immunization” and “yellow fever”. Original articles in Portuguese or English published from January 2010 to April 2020 were included. Articles that do not address vaccine safety and those that did not contain a Brazilian author were excluded. Editorials and reviews were excluded. Discussion: 71 articles were found. Of these, 66 were excluded because they did not meet the inclusion criteria. Thus, five studies were included. They claim, based on epidemiology, that most adverse reactions are due to the immunogenicity of the pertussis component – especially in children under 12 months of age – and methodological administration errors – such as primary vaccination in those over 60 years of age. The most common effects are fever, rash and hypersensitivity. Adverse reactions are rare, and serious ones, such as viceroscopic disease, are a minority. This scenario is caused by high efficiency in the quality verification of the National Immunization Program in Brazil. However, the efficiency of vaccination could increase through legislative mechanisms that regulate the forms of presentation on the packaging, avoiding waste and expiration. Conclusion: Little is national production on the theme. References indicate high safety and quality in the surveillance and legislation of immunization - despite, greater training of professionals involved in prescription and administration could increase the cost benefit of vaccination. Thus, the discussion and clarification about vaccine safety is one of the foundations for opposing the growing of against-vaccination trend. Financial Support: This scientific work does not have financial support from institutions or people.

Safety of yellow fever vaccination in pregnancy: findings from a cohort of active duty US military women.

Yellow fever (YF) is a rare viral disease that can be prevented through receipt of a live attenuated vaccine. In the US military, service members must receive the YF vaccine before assignment to endemic areas, putting active duty service women at heightened risk for inadvertent exposure during preconception or pregnancy. Few studies have investigated the safety of YF vaccination in pregnancy to date, and none in a military population. Department of Defense Birth and Infant Health Research program data were used to identify pregnancies and infants among active duty US military women, 2003-2014. Multivariable regression models estimated associations with YF vaccine exposure during preconception/pregnancy and adverse outcomes (e.g. spontaneous abortion, birth defects). Sensitivity analyses were performed that excluded pregnancies exposed to other live vaccines. For analyses of birth defects only, a secondary sensitivity analysis was performed that excluded infants diagnosed with chromosomal anomalies. Of the 196 802 pregnancies and 160 706 singleton infants identified, 1347 (0.7%) and 1132 (0.7%), respectively, were exposed to the YF vaccine. No increased risks for adverse pregnancy or infant outcomes were observed in the main analysis. In sensitivity analyses that excluded pregnancies exposed to other live vaccines, preconception YF vaccine exposure was associated with birth defects [adjusted risk ratio (aRR) = 1.71, 95% confidence interval (CI) = 1.08-2.73]; this association was attenuated when further excluding infants with chromosomal anomalies (aRR = 1.59, 95% CI = 0.97-2.62). Overall, YF vaccine exposure did not appear to be associated with most adverse outcomes among this population of pregnant military women. A tenuous association between preconception YF vaccine exposure and birth defects was observed in sensitivity analyses, which may warrant further investigation.

Ensuring the Safety of Yellow Fever Vaccination in Travelers-The Experience at a Large U.S. Academic Medical Center in Colorado.

Background: Yellow fever (YF) virus has the potential to cause fatal outcomes among at-risk individuals visiting endemic areas. Vaccinating travelers who are at risk is necessary to prevent virus-related life-threatening complications. We lack data on the clinical features of persons seeking YF vaccination. We aim to describe the characteristics of a cohort of persons receiving the YF vaccine before travel. Methods: A retrospective analysis of 964 travelers receiving the YF vaccine (Stamaril®) from Oct 2016 to Jul 2019 was performed at the University of Colorado Hospital, U.S. Percentages, means, and standard deviations were calculated. A multivariate logistic regression model was built to evaluate the association between receiving YF vaccination less than 10 days before departure and visiting friends and relatives (VFR). Results: The average age of the subjects was 39 ± 18 years with a range of nine months to 83 years. Persons who were 60 years of age and older represented 17%. Women consisted of 52%, and most of the travelers were Caucasians (64%). Travelers reported traveling to Africa (57%) or South America (40%). The primary destinations for travelers overall were Kenya (19%), Uganda (11%), and Tanzania (11%) in Africa; and Peru (14%) and Brazil (13%) in South America. The most common reasons for travel included leisure (44%), VFR (18%), and mission trips (10%). Comorbidities included a history of hematologic disorders (4%), HIV infection (2%), and diabetes mellitus (3%). The average duration between vaccine administration and travel was 43 days. Those VFR were two times more likely to receive the YF vaccination <10 days before departure. Conclusions: Identifying the type of travel, itinerary, and underlying medical conditions allows providers to administer the YF vaccine to travelers safely. There is a need to identify strategies to improve the timing of YF vaccination among VFR travelers.

Brazilian recommendations on the safety and effectiveness of the yellow fever vaccination in patients with chronic immune-mediated inflammatory diseases

BackgroundIn Brazil, we are facing an alarming epidemic scenario of Yellow fever (YF), which is reaching the most populous areas of the country in unvaccinated people. Vaccination is the only effective tool to prevent YF. In special situations, such as patients with chronic immune-mediated inflammatory diseases (CIMID), undergoing immunosuppressive therapy, as a higher risk of severe adverse events may occur, assessment of the risk-benefit ratio of the yellow fever vaccine (YFV) should be performed on an individual level.Main body of the abstractFaced with the scarcity of specific orientation on YFV for this special group of patients, the Brazilian Rheumatology Society (BRS) endorsed a project aiming the development of individualized YFV recommendations for patients with CIMID, guided by questions addressed by both medical professionals and patients, followed an internationally validated methodology (GIN-McMaster Guideline Development). Firstly, a systematic review was carried out and an expert panel formed to take part of the decision process, comprising BRS clinical practitioners, as well as individuals from the Brazilian Dermatology Society (BDS), Brazilian Inflammatory Bowel Diseases Study Group (GEDIIB), and specialists on infectious diseases and vaccination (from Tropical Medicine, Infectious Diseases and Immunizations National Societies); in addition, two representatives of patient groups were included as members of the panel. When the quality of the evidence was low or there was a lack of evidence to determine the recommendations, the decisions were based on the expert opinion panel and a Delphi approach was performed. A recommendation was accepted upon achieving ≥80% agreement among the panel, including the patient representatives. As a result, eight recommendations were developed regarding the safety of YFV in patients with CIMID, considering the immunosuppression degree conferred by the treatment used. It was not possible to establish recommendations on the effectiveness of YFV in these patients as there is no consistent evidence to support these recommendations.ConclusionThis paper approaches a real need, assessed by clinicians and patient care groups, to address specific questions on the management of YFV in patients with CIMID living or traveling to YF endemic areas, involving specialists from many areas together with patients, and might have global applicability, contributing to and supporting vaccination practices. We recommended a shared decision-making approach on taking or not the YFV.

Immunogenicity and Safety of Yellow Fever Vaccine in Allogeneic Hematopoietic Stem Cell Transplant Recipients After Withdrawal of Immunosuppressive Therapy.

As a live attenuated vaccine, yellow fever vaccine (YFV) is not routinely performed after allogeneic hematopoietic stem cell transplant (HSCT) despite it being the only efficient preventive therapy. We retrospectively identified 21 HSCT recipients immunized with YFV at a median of 39 months after HSCT and a median of 33 months after withdrawal of immunosuppression without any side effects. Eighteen evaluable patients had protective immunity after YFV. We also observed that a third of the recipients vaccinated with YFV before HSCT had persistent protective immunity after HSCT.

The Safety of Yellow Fever Vaccines, International Experience for different Cases

Yellow fever virus is from family flaviviridae and is endemic in African countries and Latin America. Over 900 million people are living in endemic area and are risked from infection of yellow fever. Illness ranges in severity from a self-limited febrile illness to severe liver disease with bleeding and is diagnosed based on symptoms, physical findings, and laboratory testing and travel history, including the possibility of exposure to infected mosquitoes. There is no specific treatment for yellow fever; care is based on symptoms. The steps necessary to prevent yellow fever virus infection include using insect repellent, wearing protective clothing and getting vaccinated. Yellow fever vaccine is recommended for endemic countries and over 500 million people are vaccinated with yellow fever vaccine 17D. The countries which are not endemic are recommended according to International Health Regulation to vaccinate people in cases of travelling in endemic areas to avoid the importation of yellow fever virus and epidemic outbreak in the country. The cases of yellow fever infection are reported and in countries free of yellow fever virus. According the data based on the different studies in different countries the yellow fever 17D and 17DD vaccines are very safe and effective against illness and the best way for preventing yellow fever infection.

Yellow fever vaccination status and safety in hemodialysis patients.

The adverse effects of yellow fever (YF) vaccine in dialysis patients are not well known. There is concern about the risks and benefits of the vaccine in immunocompromised patients living in endemic areas, particularly given the risk of resurgence of urban YF with the spread of Aedes aegypti mosquitoes. The purpose of this study was to assess the coverage and safety of YF vaccine in chronic dialysis patients. A cross-sectional study of 130 chronic dialysis patients was performed. Data were collected on clinical characteristics and YF vaccine status. Patients not vaccinated against YF or without a booster vaccination within the last 10 years were referred to receive the vaccine, and adverse effects were monitored. Previous vaccination was verified in 44 patients within the last 10 years and in 26 patients at more than 10 years ago, with no mention of adverse effects. Thirty-six patients had never been vaccinated and 24 had an unknown vaccination status. Of the total 86 patients referred for immunization, 45 actually received the YF vaccine, with 24.4% experiencing mild local adverse effects and 4.4% experiencing fever. No serious adverse effects attributable to YF vaccine were observed (anaphylaxis, neurological or viscerotropic disease). YF vaccine coverage among hemodialysis patients is low, and the vaccine appeared to be safe in this population with a small sample size.

Immunogenicity and safety of yellow fever vaccine among 115 HIV-infected patients after a preventive immunisation campaign in Mali

The immune response to yellow fever (YF) vaccine and its safety among HIV-infected individuals living in YF endemic areas is not well understood. Following a national YF preventive immunisation campaign in Mali in April 2008, we assessed the immunogenicity and safety of 17D yellow fever vaccine (17DV) among HIV-infected patients in two HIV treatment centres in Bamako, Mali, by testing for neutralising antibodies and identifying serious adverse events following immunisation (AEFI). A YF neutralisation titre (NT) of 1:≥20 was considered to be adequate and protective. A serious AEFI included hospitalisation, any life-threatening condition, or death, occurring within 30 days following 17DV administration. Of 115 HIV-infected patients who reported having received 17DV, 110 (96%) were on combination antiretroviral therapy and 83 patients were tested for neutralising antibodies. Around the time of vaccination, median CD4 cell count was 389 cells/mm3 (IQR 227–511cells/mm3); HIV-RNA was undetectable in 24 of 46 patients tested. Seventy-six (92%) of 83 participants had adequate immune titres 9 months after the immunisation campaign. Previous vaccination or flavivirus exposure could contribute to this finding. No serious AEFI was found in the 115 participants. In this small series, YF vaccine appeared to be immunogenic with a favourable safety profile in HIV-infected patients on antiretroviral therapy. Higher CD4 cell counts and suppressed HIV-RNA were associated with the presence of an adequate immune titre and higher NTs.

Immunogenicity and Safety of Yellow Fever Vaccination for 102 HIV‐Infected Patients

Yellow fever vaccine (17DV) has been investigated incompletely in human immunodeficiency virus (HIV)-infected patients, and adequate immunogenicity and safety are of concern in this population. In the Swiss HIV Cohort Study, we identified 102 patients who received 17DV while they were HIV infected. We analyzed neutralization titers (NTs) after 17DV administration using the plaque reduction neutralization test. NTs of 1:>or=10 were defined as reactive, and those of 1:<10 were defined as nonreactive, which was considered to be nonprotective. The results were compared with data for HIV-uninfected individuals. Serious adverse events were defined as hospitalization or death within 6 weeks after receipt of 17DV. At the time of 17DV administration, the median CD4 cell count was 537 cells/mm(3) (range, 11-1730 cells/mm(3)), and the HIV RNA level was undetectable in 41 of 102 HIV-infected patients. During the first year after vaccination, fewer HIV-infected patients (65 [83%] of 78; P = .01) than HIV-uninfected patients revealed reactive NTs, and their NTs were significantly lower (P < .001) than in HIV-uninfected individuals. Eleven patients with initially reactive NTs lost these reactive NTs <or= 5 years after vaccination. Higher NTs during the first year after vaccination were associated with undetectable HIV RNA levels, increasing CD4 cell count, and female sex. We found no serious adverse events after 17DV administration among HIV-infected patients. Compared with HIV-uninfected individuals, HIV-infected patients respond to 17DV with lower reactive NTs, more often demonstrate nonprotective NTs, and may experience a more rapid decline in NTs during follow-up. Vaccination with 17DV appears to be safe in HIV-infected individuals who have high CD4 cell counts, although rate of serious adverse events of up to 3% cannot be excluded.

Vaccination in Travelers.

Vaccination of populations throughout the world has led to dramatic decreases in morbidity and mortality from many infectious diseases, including poliomyelitis and measles. In the United States, for example, morbidity and mortality from invasive disease from Haemophilus influenzae type b has decreased more than 99%. International travelers should ensure that they are up-to-date on their routine immunizations and then consider vaccination against other diseases based on risk. This article reviews new vaccines such as those against rotavirus, Lyme disease, and enterotoxigenic Escherichia coli and provides updated information on the risk of typhoid fever and the efficacy of vaccination against it. The use of hepatitis A vaccine in outbreak control, the safety of yellow fever vaccine, and the importance of protecting travelers against rabies exposure are also discussed. Vaccination is an important way for travelers to maintain their health before, during, and after travel.