Yellow fever vaccination of human immunodeficiency virus-infected patients: report of 2 cases.
Yellow fever vaccine (17D, a live attenuated virus vaccine) was effective and safe in 2 human immunodeficiency virus-infected patients without severe immunosuppression, one of whom traveled to Kenya and the other of whom traveled to Senegal. (+info)
Influence of the IL-1Ra gene polymorphism on in vivo synthesis of IL-1Ra and IL-1beta after live yellow fever vaccination.
The inflammatory response in infectious and autoimmune diseases is regulated by the balance between pro- and anti-inflammatory cytokines. The IL-1 complex contains polymorphic genes coding for IL-1alpha, IL-1beta and IL-1Ra. The IL-1Ra (variable number of tanden repeat) VNTR polymorphism has been shown to influence the capacity to produce IL-1beta and IL-1Ra after in vitro stimulation. Allele 2 of this polymorphism is associated with a number of inflammatory diseases. To determine the impact of the IL-1Ra polymorphism on in vivo human cytokine synthesis, we used a yellow fever vaccination model for the induction of cytokine synthesis in healthy volunteers. Two different yellow fever vaccines were used. After administration of the RKI vaccine (34 volunteers), plasma TNF-alpha concentration increased from 13.4 +/- 0.9 pg/ml to 23.3 +/- 1.1 pg/ml (P < 0.001), and plasma IL-1Ra concentration increased from 308 +/- 25 pg/ml to 1019 +/- 111 pg/ml (P < 0.001), on day 2. Using Stamaril vaccine, no increase in the plasma concentrations of either TNF-alpha or IL-1Ra could be detected (n = 17). Only the RKI vaccine induced TNF-alpha synthesis after in vitro stimulation of MNC. Carriers of allele 2 of the IL-1Ra polymorphism had increased baseline concentrations of IL-1Ra (350 +/- 32 pg/ml) compared with non-carriers (222 +/- 18 pg/ml, P < 0.001), and decreased concentrations of IL-1beta (0.9 +/- 0.2 pg/ml for carriers versus 2.8 +/- 0.7 pg/ml for non-carriers, P = 0.017). After yellow fever vaccination (RKI vaccine), no significant differences in the increase of IL-1Ra plasma levels were detected between carriers and non-carriers of allele 2 of the IL-1Ra gene polymorphism. This is the first study to examine the influence of this genetic polymorphism on in vivo-induced human IL-1beta and IL-1Ra synthesis. Baseline concentrations of IL-1Ra and IL-1beta were significantly influenced by the IL-1Ra polymorphism. No influence of the IL-1Ra polymorphism on the in vivo-induced production of IL-1Ra and IL-1beta could be detected. (+info)
The early use of yellow fever virus strain 17D for vaccine production in Brazil--a review.
The use of yellow fever (YF) virus 17D strain for vaccine production adapted in Brazil since its introduction in 1937 was reviewed. This was possible due to the availability of official records of vaccine production. The retrieved data highlight the simultaneous use of several serially passaged 17D substrain viruses for both inocula and vaccine preparation that allowed uninterrupted production. Substitution of these substrain viruses became possible with the experience gained during quality control and human vaccination. Post-vaccinal complications in humans and the failure of some viruses in quality control tests (neurovirulence for monkeys) indicated that variables needed to be reduced during vaccine production, leading to the development of the seed lot system. The 17DD substrain, still used today, was the most frequently used substrain and the most reliable in terms of safety and efficacy. For this reason, it is possible to derive an infectious cDNA clone of this substrain combined with production in cell culture that could be used to direct the expression of heterologous antigens and lead to the development of new live vaccines. (+info)
Travel vaccines and elderly persons: review of vaccines available in the United States.
Aging is associated with alterations in immune responses and may lead to clinically significant changes in the safety, immunogenicity, and protective efficacy of certain vaccines. This review summarizes published data regarding the effects of age on responses after immunization with vaccines generally administered before travel. The specific vaccines discussed in detail include hepatitis A, typhoid, yellow fever, Japanese encephalitis, and rabies vaccines. There is some evidence of diminished serological responses to hepatitis A and rabies vaccines in older individuals. In addition, increased toxic effects following yellow fever vaccination in elderly recipients have recently been reported. However, many travel-related vaccines have never been studied specifically in elderly populations. Consideration of potential age-related differences in responses to travel vaccines is becoming increasingly important as elderly persons more frequently venture to exotic destinations. (+info)
Antibody response to 17D yellow fever vaccine in Ghanaian infants.
OBJECTIVES: To assess the seroresponses to yellow fever vaccination at 6 and 9 months of age; assess any possible adverse effects of immunization with the 17D yellow fever vaccine in infants, particularly at 6 months of age. METHODS: Four hundred and twenty infants who had completed BCG, OPV and DPT immunizations were randomized to receive yellow fever immunization at either 6 or 9 months. A single dose of 0.5 ml of the reconstituted vaccine was administered to each infant by subcutaneous injection. To determine the yellow fever antibody levels of the infants, each donated 1 ml whole blood prior to immunization and 3 months post-immunization. Each serum sample was titred on Vero cells against the vaccine virus. FINDINGS: The most common adverse reactions reported were fever, cough, diarrhoea and mild reactions at the inoculation site. The incidences of adverse reactions were not statistically different in both groups. None of the pre-immunization sera in both age groups had detectable yellow fever antibodies. Infants immunized at 6 months recorded seroconversion of 98.6% and those immunized at 9 months recorded 98% seroconversion. The GMT of their antibodies were 158.5 and 129.8, respectively. CONCLUSIONS: The results indicate that seroresponses to yellow fever immunization at 6 and 9 months as determined by seroconversion and GMTs of antibodies are similar. The findings of good seroresponses at 6 months without significant adverse effects would suggest that the 17D yellow fever vaccine could be recommended for use in children at 6 months in outbreak situations or in high risk endemic areas. (+info)
Advanced age a risk factor for illness temporally associated with yellow fever vaccination.
In 1998, the Centers for Disease Control and Prevention was notified of severe illnesses and one death, temporally associated with yellow fever (YF) vaccination, in two elderly U.S. residents. Because the cases were unusual and adverse events following YF vaccination had not been studied, we estimated age-related reporting rates for systemic illness following YF vaccination. We found that the rate of reported adverse events among elderly vaccinees was higher than among vaccinees 25 to 44 years of age. We also found two additional deaths among elderly YF vaccinees. These data signal a potential problem but are not sufficient to reliably estimate incidence rates or to understand potential underlying mechanisms; therefore, enhanced surveillance is needed. YF remains an important cause of severe illness and death, and travel to disease-endemic regions is increasing. For elderly travelers, the risk for severe illness and death due to YF infection should be balanced against the risk for systemic illness due to YF vaccine. (+info)
Fever, jaundice, and multiple organ system failure associated with 17D-derived yellow fever vaccination, 1996-2001.
At the June 2001 meeting of the Advisory Committee for Immunization Practices (ACIP), seven cases of multiple organ system failure (MOSF) in recipients of 17D-derived yellow fever (YF) vaccine were presented. In response, an ACIP working group was formed to review the cases, assess the risk for serious adverse events following YF vaccination, and consider revision of the 1990 YF vaccination recommendations. This notice summarizes these cases and describes an enhanced surveillance program designed to refine risk estimates and improve histopathologic documentation of MOSF potentially associated with YF vaccination. (+info)
Human cytotoxic T lymphocyte responses to live attenuated 17D yellow fever vaccine: identification of HLA-B35-restricted CTL epitopes on nonstructural proteins NS1, NS2b, NS3, and the structural protein E.
Yellow fever virus (YFV) is a re-emerging problem despite the existence of an effective live-attenuated vaccine. The induction of YFV-neutralizing antibodies undoubtedly contributes to vaccine efficacy, but T lymphocyte responses to YFV likely play a role in long-term efficacy. We studied the T lymphocyte responses to YFV in four vaccinees. Proliferation and cytolytic responses to YFV were demonstrated in all subjects. We isolated 13 YFV-specific CD8(+) CTL lines that recognized epitopes on the E, NS1, NS2b, and NS3 proteins; eight CTL lines were HLA-B35-restricted. YFV-specific T cell responses were detectable by IFN gamma ELISPOT assays 14 days postvaccination, with T cell frequencies sustained for up to 19 months. To our knowledge, this is the first report of human T lymphocyte responses following YFV vaccination. These results indicate that the live 17D YFV vaccine induced CD8(+) T cell responses directed against at least four different HLA-B35-restricted YFV epitopes. (+info)