Prevalence of IgG varicella zoster virus antibodies in the Kuikuro and Kaiabi indigenous communities in Xingu National Park, Brazil, before varicella vaccination

The purpose of the study was to estimate the prevalence of IgG antibodies against varicella zoster virus (VZV) in the two most populated indigenous ethnic groups from Xingu Indigenous National Park, in Brazil, prior to the introduction of vaccination against the disease, and to determine the positive and the negative predictive values of a history of varicella infection. In 2001, 589 inhabitants of two Kuikuro villages and three Kaiabi villages were evaluated and provided information concerning previous varicella infection. An indirect immunosorbent assay (ELISA) to detect IgG anti-VZV antibodies was performed in 224 blood samples - volunteer selection had no interference of anamnesis. IgG prevalence was 80.8% (95% Confidence Interval: 76% - 86%). The seroepidemiology of varicella in Xingu National Park prior to varicella vaccine introduction was comparable to the Brazilian national seroprevalence described in the literature, and so were the positive (98%) and the negative predictive value (41%) of the referred history.

Effectiveness of the Brazilian influenza vaccination policy, a systematic review

Since 1999, Brazil has undertaken annual influenza vaccine campaigns, free of charge, targeting the elderly population, health professionals, and immune-deficient patients. We conducted a systematic review of literature in order to evaluate the effectiveness of the initiative. We used the keywords influenza, vaccine, Brazil and effectiveness to search the main databases. Thirty-one studies matched our inclusion and exclusion criteria. Influenza vaccine coverage among the elderly is high, though not as high as suggested by the official figures. Estimates on effectiveness are scarce. The majority come from ecological studies that show a modest reduction in mortality and hospital admissions due to influenza-related causes. Such reduction is not evident in the North and Northeastern states of Brazil, a finding that is probably related to the different seasonal pattern of influenza in equatorial and tropical regions. Brazilian epidemiologists still owe society better-designed studies addressing the effectiveness of influenza vaccine campaigns.

Pandemic influenza A/H1N1 vaccination coverage, adverse reactions, and reasons for vaccine refusal among medical students in Brazil

The aim of this cross-sectional study was to determine, among medical students at a public university in Rio de Janeiro, Brazil, the acceptance of the pandemic influenza A/H1N1 vaccine during the 2010 mass immunization campaign and the vaccine safety in this group and, among unvaccinated students, the reasons for refusing vaccination. Of a total of 858 students, 678 (79%) participated in the study. Vaccination coverage was 60.4% among students aged 20 to 39 years (an age group targeted for vaccination) and 43.8% among those who did not belong to this age group. The most frequent adverse reactions to the vaccine were pain at the injection site (8.7%) and fever (7.9%). There were no serious adverse reactions. Among students aged 20 to 39 years, the most common reasons for refusing the vaccine were "lack of time" (42.4%), "fear of adverse reactions" (41.9%), and "difficult access to the vaccine" (11.5%). Other reasons for vaccine refusal were "uncertainties about vaccine safety and efficacy" and "vaccination was not needed". To increase the acceptance of the influenza vaccine, a comprehensive immunization program should be offered to these students.

Designing a vaccination strategy against dengue

In this work we propose a mathematical approach to estimate the dengue force of infection, the average age of dengue first infection, the optimum age to vaccinate children against dengue in a routine fashion and the optimum age interval to introduce the dengue vaccine in a mass vaccination campaign. The model is based on previously published models for vaccination against other childhood infections, which resulted in actual vaccination programmes in Brazil. The model was applied for three areas of distinct levels of endemicity of the city of Recife in Northeastern State of Pernambuco, Brazil. Our results point to an optimal age to introduce the dengue vaccine in the routine immunization programme at two years of age and an age interval to introduce a mass vaccination between three and 14 years of age.

HEPATITIS B VACCINATION COVERAGE AND POSTVACCINATION SEROLOGIC TESTING AMONG MEDICAL STUDENTS AT A PUBLIC UNIVERSITY IN BRAZIL

The aim of this cross-sectional study was to determine the hepatitis B vaccination coverage among medical students at a public university in Rio de Janeiro, Brazil, and their compliance with the postvaccination serologic testing recommendations. Of the total of 858 students, 675 (78.7%) participated in the study. Among the participants, 48.9% (95% CI: 45.1% to 52.7%) were vaccinated against hepatitis B (received ≥ 3 doses of the vaccine), 31.6% were not (received 0, 1 or 2 doses), and 19.6% did not know their vaccination status. Hepatitis B vaccination coverage increased from 26.0% among first-year students to 70.6% among sixth-year students while the prevalence of unknown vaccination status decreased from 39.7% among first-year students to 2.4% among sixth-year students. The frequency of unvaccinated students ranged from 23.7% among fifth-year students to 34.4% among first-year students. Only 34.8% of the vaccinated students performed the anti-HBs testing after vaccination. Among these medical students, we found a low adherence to the hepatitis B vaccination and to the postvaccination serologic testing. A comprehensive hepatitis B immunization program should be offered to students at this medical school.

Epidemiological studies of Streptococcus pneumoniae carriage in the post-vaccination era among two risk groups: children and the elderly

Dissertation presented to obtain the Ph.D. degree in Biology/ Molecular Biology

The avirulence of the cultivated PF strain of Trypanosoma cruzi: V - the evaluation of parasitologic tests after vaccination of different animal species

After vaccination with the live PF strain of Trypanosoma cruzi, 194 blood cultures were performed in 143 mice, 9 dogs, 5 Cebus monkeys and 7 human subjects. Some of these blood cultures were simultaneously done with xenodiagnosis, subinoculation in baby mice and/or culture of viscerae. The trypanosomes isolated from the few positive cases (6,1%) were incapable of infecting baby mice were considered as cases of immunotolerance. All the other tests were negative.

The vaccination of h uman beings with live avirulent vaccine of Trypanosoma cruzi: A two year follow-up of the first two cases

A two year follow-up of the first two volunteers vaccinated icith the live PF Trypanosoma cruzi strain demonstrated that the parasitological and clinical test were negative during and after that period. Of the serological tests employed, the CFT presented, in only one case, conflicting results, particulary in one laboratory and among different laboratories. However negative results were greater than all doubtful and positive one combined. The IFT icere negative in both patients. Some comments are made about the sensibility and specificity of these tests. The author concluded that the vaccine, in spite of the very large dose used in these cases, seems to be safe for human beings.

The vaccination of human beings with a live avirulent strain of Trypanosoma cruzi: a new series of volunteers

Five human volunteers were vaccinated with a live avirulent strain of Trypanosoma cruzi and followed-up for one year. Except for a few cases of questionable results presented by only one Laboratory, ali the other clinicai, parasitological and serological tests remained negative during that period.

Recommendations for Vaccination in Adult Patients with Systemic Inflammatory Rheumatic Diseases from the Portuguese Society of Rheumatology

Serious infections are a major cause of morbidity and mortality in systemic inflammatory rheumatic disease (SIRD) patients. Although vaccination may prevent numerous infections, vaccination uptake rates are low in this group of patients. OBJECTIVES: To develop evidence-based recommendations for vaccination in SIRD patients. METHODS: We searched MEDLINE (until 31 October 2014) and EMBASE (until 14 December 2014) databases, as well as the ACR and EULAR congress abstracts (2011-2014). Patients with any systemic inflammatory rheumatic disease were included and all vaccines were considered. Any safety and efficacy outcomes were admitted. Search results were submitted to title and abstract selection, followed by detailed review of suitable studies. Data were subsequently pooled according to the type of vaccine and the SIRD considered. Results were presented and discussed by a multidisciplinary panel and systematic literature review (SLR)-derived recommendations were voted according to the Delphi method. The level of agreement among rheumatologists was assessed using an online survey. RESULTS: Eight general and seven vaccine-specific recommendations were formulated. Briefly, immunization status should routinely be assessed in all SIRD patients. The National Vaccination Program should be followed and some additional vaccines are recommended. To maximize the efficacy of vaccination, vaccines should preferably be administered 4 weeks before starting immunosuppression or, if possible when disease activity is controlled. Non-live vaccines are safe in SIRD, including immunosuppressed patients. The safety of live attenuated vaccines in immunosuppressed patients deserves further ascertainment, but might be considered in particular situations. DISCUSSION: The present recommendations combine scientific evidence with the multidisciplinary expertise of our taskforce panel and attained desirable agreement among Portuguese rheumatologists. Vaccination recommendations need to be updated on a regular basis, as more scientific data regarding vaccination efficacy and safety, emergent infectious threats, new vaccines as well as new immunomodulatory therapies become available.

Investigation of the response to the enterobacterial common antigen after typhoid vaccination

Antibodies against the Salmonella typhi enterobacterial common antigen (ECA) and the O and H antigens were investigated in sera from healthy male subjects who had been previously vaccinated with the typhoid vaccine. No serological response to ECA was observed. Sera from subjects not previously vaccinated presented titers of ECA hemagglutinins which quantitatively were related to the presence ofH titers, but not to O agglutinins but with no statistical significance. The results are discussed in relation to the possible protective immunological mechanisms in typhoid fever.