BackgroundThe live attenuated 17DD Yellow Fever vaccine is one of the most successful prophylactic interventions for controlling disease expansion ever designed and utilized in larger scale. However, increase on worldwide vaccine demands and manufacturing restrictions urge for more detailed dose sparing studies. The establishment of complementary biomarkers in addition to PRNT and Viremia could support a secure decision-making regarding the use of 17DD YF vaccine subdoses. The present work aimed at comparing the serum chemokine and cytokine kinetics triggered by five subdoses of 17DD YF Vaccine.MethodsNeutralizing antibody titers, viremia, cytokines and chemokines were tested on blood samples obtained from eligible primary vaccinees.Results and discussionThe results demonstrated that a fifty-fold lower dose of 17DD-YF vaccine (587 IU) is able to trigger similar immunogenicity, as evidenced by significant titers of anti-YF PRNT. However, only subdoses as low as 3,013 IU elicit viremia kinetics with an early peak at five days after primary vaccination equivalent to the current dose (27,476 IU), while other subdoses show a distinct, lower in magnitude and later peak at day 6 post-vaccination. Although the subdose of 587 IU is able to trigger equivalent kinetics of IL-8/CXCL-8 and MCP-1/CCL-2, only the subdose of 3,013 IU is able to trigger similar kinetics of MIG/CXCL-9, pro-inflammatory (TNF, IFN-γ and IL-2) and modulatory cytokines (IL-5 and IL-10).ConclusionsThe analysis of serum biomarkers IFN-γ and IL-10, in association to PRNT and viremia, support the recommendation of use of a ten-fold lower subdose (3,013 IU) of 17DD-YF vaccine.

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Objective: To verify if the Bio-Manguinhos 17DD yellow fever vaccine (17DD-YFV) used in lower doses is as immunogenic and safe as the current formulation.Results: Doses from 27,476 IU to 587 IU induced similar seroconversion rates and neutralizing antibodies geometric mean titers (GMTs). Immunity of those who seroconverted to YF was maintained for 10 mo. Reactogenicity was low for all groups.Methods: Young and healthy adult males (n = 900) were recruited and randomized into 6 groups, to receive de-escalating doses of 17DD-YFV, from 27,476 IU to 31 IU. Blood samples were collected before vaccination (for neutralization tests to yellow fever, serology for dengue and clinical chemistry), 3 to 7 d after vaccination (for viremia and clinical chemistry) and 30 d after vaccination (for new yellow fever serology and clinical chemistry). Adverse events diaries were filled out by volunteers during 10 d after vaccination. Volunteers were retested for yellow fever and dengue antibodies 10 mo later. Seropositivity for dengue was found in 87.6% of volunteers before vaccination, but this had no significant influence on conclusions.Conclusion: In young healthy adults Bio-Manguinhos/Fiocruz yellow fever vaccine can be used in much lower doses than usual.International Register ISRCTN 38082350.

Schistosoma haematobium is present in about 53 African countries and in the Middle East, with the helminth showing high endemicity in these regions (CEGET-CNRSAtlas-WHO/1987, home page-WHO). Urinary schistosomiasis is an infectious disease of marked epidemiological importance for both natives and tourists exposed to the helminth in endemic regions.Treatment of urinary schistosomiasis has shown great advances with the introduction of praziquantel into the therapeutic arsenal (Bormann et al. 2001, De Clerq et al. 2002. Advantages of this drug include its easy administration (40 mg/kg body weight, a single dose by the oral route), low toxicity, and low intensity of side effects (McMahon 1983, Pugh & Teesdale 1983, Kahama et al. 1999, Rey 2001. These important factors have contributed to the tolerance with and easy application of individualized and mass treatments (Stephenson et al. 1989, King et al. 1992. Nevertheless, failure of praziquantel treatment of various proportions has been reported (Herwaldt et al. 1995, Liang et al. 2000. So, it is necessary to be sure about the + Corresponding author. E-mail: silva.iran@ig.com.br PATIENTS AND METHODSThree 24-h urine samples were collected from 26 patients at minimum intervals of one week. The patients were Brazilian military men who were part of the United Nation peace mission in Mozambique in 1994, age between 26 and 55 years old, median age of 29 years. The principal condition was the report of exposure in Licungo river and signals and symptoms affecting the genitourinary tract after exposure.Helminth eggs were recovered by spontaneous sedimentation and subsequent centrifugation of the urine sample. The total urine volume was transferred to glass chalices and left to stand for 24 h. After this period, 10 ml of the initial sediment was removed with a glass pipette held close to the bottom of the chalice and centrifuged at 3500 r.p.m. for 5 min. One-hundred microliters of the centrifuged material was removed with a glass pipette held close to the bottom of the tube, mounted on a slide, coverslipped, and observed under a microscope at magnifications of 100× and 400×. For endoscopic examination, an Olympus model 19 CH cystoscope with a 30 o eyepiece was used. 446 446 446 446 Schistosoma haematobium in Brazilians • • • • • Iran Mendonça da Silva et al.After the positive diagnosis, the patients were treated with 40 mg/kg body weight praziquantel administered in a single dose. Three other 24-h urine exams were repeated at 7-day intervals by the same technique, after a minimum period of 21 days after treatment. Treatment was repeated under medical supervision to ensure the correct use of the drug. In the case of suspicion of lesions, all individuals were submitted to cystoscopy followed by biopsy and histopathological examination at 6-month intervals, after each treatment or retreatment, under the same conditions as used for the initial diagnosis. The urine examination, with the same technique, was repeated after each cistoscopy.In the case of evidence of vesical involveme...