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Background To enhance the production and availability of influenza vaccines in different regions of the world is paramount to mitigate the global burden of this disease. Instituto Butantan developed and manufactured an embryonated egg-based inactivated split-virion trivalent seasonal influenza vaccine as part of a technology transfer partnership with Sanofi Pasteur. Methods This is a phase IV, randomized, double-blind, active-controlled, multicenter clinical trial including adults 18–60 and > 60 years recruited during the 2019 southern hemisphere influenza season. Subjects were randomized 1:1 to receive either the Sanofi Pasteur Trivalent Seasonal Influenza Vaccine (SP-TIV) or Instituto Butantan Trivalent Seasonal Influenza Vaccine (IB-TIV). Hemagglutinin inhibition antibody titers were assessed pre-vaccination and 21 days post-vaccination. Results 624 participants were randomized and vaccinated. In both intention-to-treat and per-protocol analysis, non-inferiority of the SP-TIV versus IB-TIV was demonstrated for the three influenza strains. In the per-protocol analysis, the SP-GMT/IB-GMT ratios for H1N1, H3N2, and B were 0.9 (95%CI, 0.7–1.1), 1.2 (95%CI, 1.0–1.4), and 1.1 (95%CI, 0.9–1.3), respectively. Across vaccination groups, the most common adverse reactions (AR) were limited to the injection-site, including pain and tenderness. The majority of the ARs were graded 1 and/or 2 and lasted less than one day. No serious adverse reaction was observed. Conclusion This study demonstrated the non-inferiority of the immunogenicity of a single-dose of Instituto Butantan versus a single dose of the Sanofi Pasteur Seasonal Trivalent Influenza Vaccine in adults. Both vaccines were well tolerated and presented similar safety profiles.

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The emergence of potentially pandemic viruses has resulted in preparedness efforts to develop candidate vaccines and adjuvant formulations. We evaluated the dose-sparing effect and safety of two distinct squalene-based oil-in-water adjuvant emulsion formulations (IB160 and SE) with influenza A/H7N9 antigen. This phase I, randomized, double-blind, placebo-controlled, dose-finding trial (NCT03330899), enrolled 432 healthy volunteers aged 18 to 59. Participants were randomly allocated to 8 groups: 1A) IB160 + 15µg H7N9, 1B) IB160 + 7.5µg H7N9, 1C) IB160 + 3.75µg H7N9, 2A) SE + 15µg H7N9, 2B) SE + 7.5µg H7N9, 2C) SE + 3.75µg H7N9, 3) unadjuvanted vaccine 15µg H7N9 and 4) placebo. Immunogenicity was evaluated through haemagglutination inhibition (HI) and microneutralization (MN) tests. Safety was evaluated by monitoring local and systemic, solicited and unsolicited adverse events (AE) and reactions (AR) 7 and 28 days after each study injection, respectively, whereas serious adverse events (SAE) were monitored up to 194 days post-second dose. A greater increase in antibody geometric mean titers (GMT) was observed in groups receiving adjuvanted vaccines. Vaccinees receiving IB160-adjuvanted formulations showed the greatest response in group 1B, which induced an HI GMT increase of 4.7 times, HI titers ≥40 in 45.2% of participants (MN titers ≥40 in 80.8%). Vaccinees receiving SE-adjuvanted vaccines showed the greatest response in group 2A, with an HI GMT increase of 2.5 times, HI titers ≥40 in 22.9% of participants (MN titers ≥40 in 65.7%). Frequencies of AE and AR were similar among groups. Pain at the administration site and headache were the most frequent local and systemic solicited ARs. The vaccine candidates were safe and the adjuvanted formulations have a potential dose-sparing effect on immunogenicity against influenza A/H7N9. The magnitude of this effect could be further explored.

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The emergence of potentially pandemic viruses has resulted in preparedness efforts to develop candidate vaccines and adjuvant formulations. We evaluated the dose-sparing effect and safety of two distinct squalene-based oil-in-water adjuvant emulsion formulations (IB160 and SE) with influenza A/H7N9 antigen. This phase I, randomized, double-blind, placebo-controlled, dose-finding trial (NCT03330899), enrolled 432 healthy volunteers aged 18 to 59. Participants were randomly allocated to 8 groups: 1A) IB160 + 15μg H7N9, 1B) IB160 + 7.5μg H7N9, 1C) IB160 + 3.75μg H7N9, 2A) SE + 15μg H7N9, 2B) SE + 7.5μg H7N9, 2C) SE + 3.75μg H7N9, 3) unadjuvanted vaccine 15μg H7N9 and 4) placebo. Immunogenicity was evaluated through haemagglutination inhibition (HI) and microneutralization (MN) tests. Safety was evaluated by monitoring local and systemic, solicited and unsolicited adverse events (AE) and reactions (AR) 7 and 28 days after each study injection, respectively, whereas serious adverse events (SAE) were monitored up to 194 days post-second dose. A greater increase in antibody geometric mean titers (GMT) was observed in groups receiving adjuvanted vaccines. Vaccinees receiving IB160-adjuvanted formulations showed the greatest response in group 1B, which induced an HI GMT increase of 4.7 times, HI titers ≥40 in 45.2% of participants (MN titers ≥40 in 80.8%). Vaccinees receiving SE-adjuvanted vaccines showed the greatest response in group 2A, with an HI GMT increase of 2.5 times, HI titers ≥40 in 22.9% of participants (MN titers ≥40 in 65.7%). Frequencies of AE and AR were similar among groups. Pain at the administration site and headache were the most frequent local and systemic solicited ARs. The vaccine candidates were safe and the adjuvanted formulations have a potential dose-sparing effect on immunogenicity against influenza A/H7N9. The magnitude of this effect could be further explored.

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INTRODUCTION: Active pharmacovigilance studies are pivotal to better characterize vaccine safety. METHODS: These are multicenter prospective cohort studies to evaluate the safety of the 2017 and 2018 seasonal trivalent influenza vaccines (TIVs) manufactured by Instituto Butantan, by means of active pharmacovigilance practices. Elderly, children, healthcare workers, pregnant women, and women in the puerperium period were invited to participate in the study during the 2017 and 2018 Brazilian national seasonal influenza vaccination campaigns. Following immunization, participants were observed for 30 minutes and they received a participant card to register adverse events information. All safety information registered were checked at a clinical site visit 14 days after immunization and by a telephone contact 42 days after immunization for unsolicited Adverse Events (AE) and Guillain-Barré Syndrome (GBS). RESULTS: A total of 942 volunteers participated in the two studies: 305 elderly, 109 children, 108 pregnant women, 32 women in the postpartum period, and 388 health workers. Overall, the median number of AR per participant ranged from 1 to 4. The lowest median number of AR per participant was observed among healthcare workers (1 AR per participant) and the highest among pregnant women (4 AR per participant). Overall, local pain (46.6%) was the most frequent solicited local AR. The most frequent systemic ARs were: headache (22.5%) followed by fatigue (16.0%), and malaise (11.0%). The majority of solicited ARs (96%) were mild, Grades 1 or 2), only 3% were Grade 3, and 1% was Grade 4. No serious AEs, including Guillain-Barré Syndrome, were reported up to 42 days postvaccination. CONCLUSION: The results from the two studies confirmed that the 2017 and 2018 seasonal trivalent influenza vaccines produced by Instituto Butantan were safe and that active pharmacovigilance studies should be considered, when it is feasible, as an important initiative to monitor vaccine safety in the post-marketing period.

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Active pharmacovigilance studies are pivotal to better characterize vaccine safety. Methods: These are multicenter prospective cohort studies to evaluate the safety of the 2017 and 2018 seasonal trivalent influenza vaccines (TIVs) manufactured by Instituto Butantan, by means of active pharmacovigilance practices. Elderly, children, healthcare workers, pregnant women, and women in the puerperium period were invited to participate in the study during the 2017 and 2018 Brazilian national seasonal influenza vaccination campaigns. Following immunization, participants were observed for 30 minutes and they received a participant card to register adverse events information. All safety information registered were checked at a clinical site visit 14 days after immunization and by a telephone contact 42 days after immunization for unsolicited Adverse Events (AE) and Guillain-Barré Syndrome (GBS). Results: A total of 942 volunteers participated in the two studies: 305 elderly, 109 children, 108 pregnant women, 32 women in the postpartum period, and 388 health workers. Overall, the median number of AR per participant ranged from 1 to 4. The lowest median number of AR per participant was observed among healthcare workers (1 AR per participant) and the highest among pregnant women (4 AR per participant). Overall, local pain (46.6%) was the most frequent solicited local AR. The most frequent systemic ARs were: headache (22.5%) followed by fatigue (16.0%), and malaise (11.0%). The majority of solicited ARs (96%) were mild, Grades 1 or 2), only 3% were Grade 3, and 1% was Grade 4. No serious AEs, including Guillain-Barré Syndrome, were reported up to 42 days postvaccination. Conclusion: The results from the two studies confirmed that the 2017 and 2018 seasonal trivalent influenza vaccines produced by Instituto Butantan were safe and that active pharmacovigilance studies should be considered, when it is feasible, as an important initiative to monitor vaccine safety in the post-marketing period.

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Objective to describe occurrence of adverse events following immunization (AEFI) with Tdap vaccine during pregnancy. Methods this was a descriptive study using data from reports by participants in an effectiveness and immunogenicity study conducted in two hospitals in São Paulo, SP, Brazil, from 2015 to 2016. Results of the 201 mothers included in the study, 48 (23.9%) had at least one AEFI; 60 symptoms related to Tdap use were identified - pain (22.4%), swelling (2.5%), fever (1.5%), somnolence (1.0%), redness (0.5%), vomiting (0.5%), headache (0.5%), local reaction (0.5%), and fatigue (0.5%); no rare, very rare, or extremely rare adverse events were reported; all events were considered to be expected, as they are described in the vaccine package insert; outcome of all events was recovery without sequelae. Conclusion Tdap vaccine in the form adopted by the National Immunization Program is safe; no unexpected adverse events were identified among vaccinated pregnant women.

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Objective: to describe occurrence of adverse events following immunization (AEFI) with Tdap vaccine during pregnancy. Methods: this was a descriptive study using data from reports by participants in an effectiveness and immunogenicity study conducted in two hospitals in São Paulo, SP, Brazil, from 2015 to 2016. Results: of the 201 mothers included in the study, 48 (23.9%) had at least one AEFI; 60 symptoms related to Tdap use were identified – pain (22.4%), swelling (2.5%), fever (1.5%), somnolence (1.0%), redness (0.5%), vomiting (0.5%), headache (0.5%), local reaction (0.5%), and fatigue (0.5%); no rare, very rare, or extremely rare adverse events were reported; all events were considered to be expected, as they are described in the vaccine package insert; outcome of all events was recovery without sequelae. Conclusion: Tdap vaccine in the form adopted by the National Immunization Program is safe; no unexpected adverse events were identified among vaccinated pregnant women.

Objetivo: descrever a ocorrência de eventos adversos pós-vacinação (EAPV) com a vacina dTpa durante a gestação. Métodos: estudo descritivo, com dados de relatos das participantes de estudo de efetividade e imunogenicidade realizado em dois hospitais de São Paulo, SP, Brasil, entre 2015 e 2016. Resultados: das 201 mães incluídas no estudo, 48 (23,9%) apresentaram pelo menos um EAPV; foram identificados 60 sintomas relacionados ao uso da dTpa – dor (22,4%), inchaço (2,5%), febre (1,5%), sono (1,0%), vermelhidão (0,5%), vômito (0,5%), dor de cabeça (0,5%), reação local (0,5%) e cansaço (0,5%); não foram registrados eventos adversos raros, muito raros ou extremamente raros; todos os eventos foram considerados esperados e estão descritos em bula; todos tiveram desfecho para cura sem sequelas. Conclusão: a dTpa, na forma adotada pelo Programa Nacional de Imunizações (PNI), é segura; não foram identificados eventos adversos inesperados entre as gestantes imunizadas com a vacina.

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Objetivo: descrever a ocorrência de eventos adversos pós-vacinação (EAPV) com a vacina dTpa durante a gestação. Métodos: estudo descritivo, com dados de relatos das participantes de estudo de efetividade e imunogenicidade realizado em dois hospitais de São Paulo, SP, Brasil, entre 2015 e 2016. Resultados: das 201 mães incluídas no estudo, 48 (23,9%) apresentaram pelo menos um EAPV; foram identificados 60 sintomas relacionados ao uso da dTpa - dor (22,4%), inchaço (2,5%), febre (1,5%), sono (1,0%), vermelhidão (0,5%), vômito (0,5%), dor de cabeça (0,5%), reação local (0,5%) e cansaço (0,5%); não foram registrados eventos adversos raros, muito raros ou extremamente raros; todos os eventos foram considerados esperados e estão descritos em bula; todos tiveram desfecho para cura sem sequelas. Conclusão: a dTpa, na forma adotada pelo Programa Nacional de Imunizações (PNI), é segura; não foram identificados eventos adversos inesperados entre as gestantes imunizadas com a vacina.

Objetivo: describir el aparecimiento de eventos adversos posvacunación (EAPV) con la vacuna dTpa durante el embarazo. Métodos: estudio descriptivo con datos de relatos de las participantes del estudio de efectividad e inmunogenicidad realizado en dos hospitales de São Paulo, SP, Brasil, entre 2015 y 2106. Resultados: de las 201 madres del estudio, 48 (23,9%) tuvieron al menos un EAPV; se identificaron 60 síntomas relacionados al uso de dTpa - dolor (22.4%), hinchazón (2.5%), fiebre (1.5%), somnolencia (1.0%), enrojecimiento (0.5%), vómitos (0.5 %), dolor de cabeza (0.5%), reacción local (0.5%) y cansancio (0.5%) -; no se informaron eventos adversos raros, muy raros o extremadamente raros; todos los eventos se consideraron esperados y se describen en el prospecto; todos tuvieron resultados curativos sin secuelas. Conclusión: el estudio mostró que la vacuna dTpa utilizada por el Programa Nacional de Inmunización (PNI) es segura y no se identificaron eventos adversos inesperados entre las mujeres embarazadas vacunadas.

Objective: to describe occurrence of adverse events following immunization (AEFI) with Tdap vaccine during pregnancy. Methods: this was a descriptive study using data from reports by participants in an effectiveness and immunogenicity study conducted in two hospitals in São Paulo, SP, Brazil, from 2015 to 2016. Results: of the 201 mothers included in the study, 48 (23.9%) had at least one AEFI; 60 symptoms related to Tdap use were identified - pain (22.4%), swelling (2.5%), fever (1.5%), somnolence (1.0%), redness (0.5%), vomiting (0.5%), headache (0.5%), local reaction (0.5%), and fatigue (0.5%); no rare, very rare, or extremely rare adverse events were reported; all events were considered to be expected, as they are described in the vaccine package insert; outcome of all events was recovery without sequelae. Conclusion: Tdap vaccine in the form adopted by the National Immunization Program is safe; no unexpected adverse events were identified among vaccinated pregnant women.

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Instituto Butantan is a biomedical research center and vaccine manufacturer affiliated with the São Paulo State Secretary of Health in Brazil. In 2013, Instituto Butantan successfully licensed its trivalent influenza vaccine, in order to support the Brazilian National Immunization Program's influenza vaccination strategy, which was introduced in 1999. In order to respond to the increasing influenza vaccine demand worldwide, Instituto Butantan is undergoing prequalification of its trivalent influenza vaccine by the World Health Organization (WHO). A key requirement of the prequalification review was the submission of a pharmacovigilance plan, including an active surveillance evaluation, for the trivalent influenza vaccine, and proof of a functional pharmacovigilance system at Instituto Butantan. The aim of this paper is to describe the capacity strengthening process of the pharmacovigilance system at Instituto Butantan for the WHO prequalification of the trivalent influenza vaccine. This process was supported by PATH and the U.S. Federal Government Biomedical Advanced Research and Development Authority (BARDA). The key strategic axes for this capacity strengthening process included the improvement of organizational structure, human resources training, internal processes and procedures, appropriate documentation, and acquisition of an E2B compliant pharmacovigilance database. The project led to the establishment of a functional pharmacovigilance system compliant with international regulatory requirements.

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Instituto Butantan is a biomedical research center and vaccine manufacturer affiliated with the São Paulo State Secretary of Health in Brazil. In 2013, Instituto Butantan successfully licensed its trivalent influenza vaccine, in order to support the Brazilian National Immunization Program's influenza vaccination strategy, which was introduced in 1999. In order to respond to the increasing influenza vaccine demand worldwide, Instituto Butantan is undergoing prequalification of its trivalent influenza vaccine by the World Health Organization (WHO). A key requirement of the prequalification review was the submission of a pharmacovigilance plan, including an active surveillance evaluation, for the trivalent influenza vaccine, and proof of a functional pharmacovigilance system at Instituto Butantan. The aim of this paper is to describe the capacity strengthening process of the pharmacovigilance system at Instituto Butantan for the WHO prequalification of the trivalent influenza vaccine. This process was supported by PATH and the U.S. Federal Government Biomedical Advanced Research and Development Authority (BARDA). The key strategic axes for this capacity strengthening process included the improvement of organizational structure, human resources training, internal processes and procedures, appropriate documentation, and acquisition of an E2B compliant pharmacovigilance database. The project led to the establishment of a functional pharmacovigilance system compliant with international regulatory requirements.

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Vaccination has been a successful strategy in influenza prevention. However, despite the safety and efficacy of the vaccines, they can cause adverse events following immunization (AEFI). Moreover, due to the vaccination success, most of vaccine-preventable diseases (VPD) have become rare, and public attention has been shifted from VPD to the AEFI associated with vaccination. This manuscript describes the safety of Instituto Butantan (IB) seasonal trivalent influenza vaccine (TIV) from 2013 to 2017. AEFI data were received by the Department of Pharmacovigilance of IB (PV-IB), from January the 1st 2013 to December the 31st 2017, and were recorded in an electronic database (OpenClinica (c)). PV-IB received 1,415 Individual Case Safety Reports (ICSR) associated with the TIV; 1,253 ICSR with at least one AEFI were analyzed and 4,140 AEFI were identified. The other 162 (11.4%) cases did not present any symptom. Among the total of AEFI, 405 (9.8%) were classified as serious. AEFI with the highest incidence rates per 100,000 doses of TIV were: "local pain" (0.28), "local erythema" (0.23), "local warmth" (0.22), "local swelling" (0.20) and "fever" (0.19). PV-IB received 175 (4.2%) occurrences of SAE of special interest, of which 75 (1.8%) anaphylaxis/anaphylactic reactions, 56 (1.4%) neurological syndromes (including seven Guillain-Barre Syndrome) and 44 (1.1%) convulsion/febrile convulsion. The results of this manuscript suggested that Instituto Butantan trivalent influenza vaccine (IB-TIV) is safe, as most of the reported AEFI were classified as non-serious. AEFI described for the IB-TIV are in agreement with the ones described in the literature for similar vaccines.

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Vaccination has been a successful strategy in influenza prevention. However, despite the safety and efficacy of the vaccines, they can cause adverse events following immunization (AEFI). Moreover, due to the vaccination success, most of vaccine-preventable diseases (VPD) have become rare, and public attention has been shifted from VPD to the AEFI associated with vaccination. This manuscript describes the safety of Instituto Butantan (IB) seasonal trivalent influenza vaccine (TIV) from 2013 to 2017. AEFI data were received by the Department of Pharmacovigilance of IB (PV-IB), from January the 1st 2013 to December the 31st 2017, and were recorded in an electronic database (OpenClinica©). PV-IB received 1,415 Individual Case Safety Reports (ICSR) associated with the TIV; 1,253 ICSR with at least one AEFI were analyzed and 4,140 AEFI were identified. The other 162 (11.4%) cases did not present any symptom. Among the total of AEFI, 405 (9.8%) were classified as serious. AEFI with the highest incidence rates per 100,000 doses of TIV were: "local pain" (0.28), "local erythema" (0.23), "local warmth" (0.22), "local swelling" (0.20) and "fever" (0.19). PV-IB received 175 (4.2%) occurrences of SAE of special interest, of which 75 (1.8%) anaphylaxis/anaphylactic reactions, 56 (1.4%) neurological syndromes (including seven Guillain-Barré Syndrome) and 44 (1.1%) convulsion/febrile convulsion. The results of this manuscript suggested that Instituto Butantan trivalent influenza vaccine (IB-TIV) is safe, as most of the reported AEFI were classified as non-serious. AEFI described for the IB-TIV are in agreement with the ones described in the literature for similar vaccines.

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OBJECTIVE: to describe the safety profile of the heterologous serum produced by the Butantan Institute (BI) of São Paulo-SP, Brazil. METHODS: a descriptive study of adverse events (AEs) post-exposure to serum produced by the BI, encoded in the medical terminology of the Medical Dictionary for Regulatory Activities (MedDRA), and spontaneously reported to BI from 2012 to 2015. RESULTS: 52 individuals reported AEs, mainly related to Bothrops antivenom (n=11), diphtheria antitoxin (n=9) and unspecified snakebite serum (n=9); a mean of 3.2 AEs per individual was observed; among the total of 173 AEs, 63.0% were expected considering that they were described in the package insert; most of them were classified as skin and subcutaneous tissue disorders (30.6%); there were six deaths temporally related to the use of serum, but this association was discarded. CONCLUSION: in the studied period, the serum produced by the BI had no changes in their safety profiles, considering that the AEs were expected, according to the information previously described in the package insert.

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Resumo OBJETIVO: descrever o perfil de segurança dos soros heterólogos produzidos pelo Instituto Butantan (IB) de São Paulo-SP, Brasil. MÉTODOS: estudo descritivo dos relatos de eventos adversos (EA) pós-exposição aos soros produzidos pelo IB, codificados pela terminologia do Dicionário Médico para Atividades Regulatórias (MedDRA), notificados espontaneamente ao IB entre 2012 e 2015. RESULTADOS: foram notificados 52 usuários com algum evento adverso relacionado, principalmente, aos soros antibotrópico (n=11), antidiftérico (n=9) e antiofídico não especificado (n=9); observaram-se, em média, 3,2 EA por indivíduo; dos 173 EA notificados, 63,0% eram esperados por serem eventos descritos em bula; os EA mais notificados foram categorizados como afecções dos tecidos cutâneos e subcutâneos (30,6%); houve seis óbitos temporalmente relacionados ao uso de soros, porém essa associação foi descartada. CONCLUSÃO: no período estudado, os soros produzidos pelo IB não apresentaram alteração em seu perfil de segurança, já que os EA relatados eram esperados conforme informação descrita em bula.

Abstract OBJECTIVE: to describe the safety profile of the heterologous serum produced by the Butantan Institute (BI) of São Paulo-SP, Brazil. METHODS: a descriptive study of adverse events (AEs) post-exposure to serum produced by the BI, encoded in the medical terminology of the Medical Dictionary for Regulatory Activities (MedDRA), and spontaneously reported to BI from 2012 to 2015. RESULTS: 52 individuals reported AEs, mainly related to Bothrops antivenom (n=11), diphtheria antitoxin (n=9) and unspecified snakebite serum (n=9); a mean of 3.2 AEs per individual was observed; among the total of 173 AEs, 63.0% were expected considering that they were described in the package insert; most of them were classified as skin and subcutaneous tissue disorders (30.6%); there were six deaths temporally related to the use of serum, but this association was discarded. CONCLUSION: in the studied period, the serum produced by the BI had no changes in their safety profiles, considering that the AEs were expected, according to the information previously described in the package insert.

Resumen OBJETIVO: describir el perfil de seguridad de los sueros heterólogos producidos por el Instituto Butantan (IB) de São Paulo-SP, Brasil. MÉTODOS: estudio descriptivo de los informes de eventos adversos (EAs) post-exposición a los sueros del IB y codificados según el Diccionario Médico para Actividades Regulatorias (MedDRA). RESULTADOS: 52 usuarios presentaron EAs relacionados con los sueros antibotrópico (n=11), antidiftérico (n=9) y antiofídico no especificado (n=9); se observó, en los EAs, 3,2 de media por persona; de los 173 EAs reportados, 63,0% fueron "esperados", ya que figuran descritos en la bula farmacológica; los EAs más reportados fueron los trastornos de piel y tejido subcutáneo (30,6%); hubo seis muertes, pero se descartó la asociación con el uso de suero. CONCLUSIÓN: durante el período de estudio, los sueros del IB no mostraron ningún cambio en su perfil de seguridad, ya que los EAs reportados eran esperados conforme información descrita en la bula.

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BACKGROUND: Children play an important role in maintaining the transmission of influenza. Evidence suggests that vaccination of school-age children can reduce transmission to unvaccinated household contacts. We evaluated the direct and indirect effectiveness of the 2009 inactivated seasonal influenza vaccine in vaccinated schoolchildren and their unvaccinated household contacts. METHODS: This was a double-blind cluster randomized trial involving 10 schools and 1742 schoolchildren as well as 5406 household contacts. The schools were randomly assigned to receive the influenza vaccine or the control vaccine. After vaccination, the schoolchildren and household contacts were followed for 6 months to identify cases of acute respiratory infection (ARI). Reverse-transcriptase polymerase chain reaction was performed for the diagnosis of influenza. RESULTS: A total of 632 ARI cases were detected. Of those, 103 tested positive for influenza virus (influenza virus A[H1N1]pdm09 virus in 55 and seasonal influenza viruses in 48). The effectiveness of the vaccine in protecting against seasonal influenza virus infection was 65·0% for the household contacts (95% CI, 19·6-84·3) and 65·0% for the schoolchildren (95% CI, 20·9-84·5). CONCLUSION: Vaccination of schoolchildren significantly protected them and their household contacts against seasonal influenza.

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Objetivo: avaliar efetividade e segurança da estratégia brasileira de vacinação contra influenza. Métodos: revisão sistemática da literatura. Foram usadas as palavras-chave influenza, Brasil, vacina, cobertura vacinal, efetividade e evento adverso na busca às seguintes bases de dados: Medical Literature Analysis and Retrieval System Online, US National Library of Medicine, Literatura Latino-Americana e do Caribe em Ciências Sociais, Biblioteca Virtual em Saúde, Scientific Electronic Library Online e Google Scholar, no período 1999 a 2013. Resultados: 784 publicações foram identificadas nas bases de dados, das quais 73 atenderam aos critérios de inclusão. As coberturas vacinais foram elevadas, porém menores que aquelas registradas no sistema de informações. Os estudos ecológicos de mortalidade e hospitalizações apresentaram resultados conflitantes: redução dos indicadores (16 artigos) e aumento (4 artigos) após introdução da vacinação. Conclusão: os estudos sugerem que a vacina é segura e efetiva, todavia a redução na mortalidade e hospitalizações por causas relacionadas à influenza foi modesta.

Objective: to evaluate the Brazilian influenza vaccination strategy's safety and effectiveness. Methods: systematic review of scientific literature. The keywords "influenza", "Brazil", "vaccine", "vaccine coverage", "effectiveness", and "adverse events" were used to search the following databases for the period 1999-2013: Medical Literature Analysis and Retrieval System Online, US National Library of Medicine, Literatura Latino-Americana e do Caribe em Ciências Sociais, Biblioteca Virtual em Saúde, Scientific Electronic Library Online, and Google Scholar. Results: 784 publications were retrieved. 73 were included in the study after applying the exclusion criteria. Vaccine coverage is high, although lower than registered on the information system. Ecological studies on influenza-related mortality and hospitalizations provide conflicting estimates, some pointing to a reduction (16 articles) and others to an increase (4 articles) in the rates after vaccine introduction. Conclusion: studies suggest that the vaccine is safe and effective, although the reduction in influenza-related mortality and hospitalizations was modest.

Objetivo: evaluar la efectividad y la seguridad de la estrategia brasileña de vacunación contra la influenza.Método: revisión sistemática de la literatura. Se usaron las palabras clave influenza, Brasil, vacuna, cobertura vacunal, efectividad y evento adverso en la búsqueda en las siguientes bases de datos: Medical Literature Analysis and Retrieval System Online, US National Library of Medicine, Literatura Latinoamericana y del Caribe en Ciencias Sociales, Biblioteca Virtual en Salud, Scientific Electronic Library Online e Google Scholar, en el período 1999 a 2013. Resultados: fueron identificadas 784 publicaciones en las bases de datos, de las cuales 73 atendieron a los criterios de inclusión. La cobertura vacunal fue elevada, aunque menor que la registrada en el sistema de informaciones. Los estudios ecológicos de mortalidad y hospitalizaciones presentaron resultados conflictuantes: reducción de los indicadores (16 artículos) y aumento (4 artículos) luego de la introducción de la vacunación.Conclusion: los estudios sugieren que la vacuna es segura y efectiva, sin embargo la reducción de la mortalidad y de hospitalizaciones por causas relacionadas a la influenza fue modesta.

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O uso da avaliação nos serviços de saúde como um instrumento para o planejamento tem aumentado dia a dia e a cobertura vacinal insere esses elementos de avaliação de serviços que tem se mostrado bastante eficiente...

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RESUMO

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.

Desde 1999 o Brasil realiza campanhas anuais de vacinação contra influenza. A vacinação é gratuita, e tem como grupos alvo os idosos, os profissionais de saúde e os pacientes com comprometimento imunitário. Nós realizamos uma revisão sistemática da literatura, com o propósito de avaliar a efetividade desta iniciativa. Foram usadas as palavras chave influenza, vacina, Brasil e efetividade, para a busca nas bases de dados mais relevantes. Trinta e um estudos se encaixaram nos nossos critérios de inclusão e exclusão. A cobertura vacinal nos idosos é alta, porém não tão alta como apresentado nos dados oficiais. Estimativas de efetividade são escassas. A maioria delas vem de estudos ecológicos, que demonstram um modesto efeito na redução da mortalidade e internações hospitalares por causas relacionadas à influenza. Esta redução não se evidencia nos estados do Norte e Nordeste do Brasil, achado que provavelmente relaciona-se ao padrão distinto de sazonalidade da influenza nas regiões equatoriais e tropicais. Os epidemiologistas brasileiros ainda devem à sociedade estudos com desenhos mais adequados à análise da efetividade das campanhas de vacinação contra influenza.

Assuntos