ABSTRACT Twenty-seven children aged seven months to 5 years were inadvertently vaccinated with a COVID-19 vaccine, the CoronaVac (Sinovac, China), an inactivated SARS-CoV-2 vaccine, in two different cities of Sao Paulo State, Brazil. After the event, these children were monitored by local pediatricians and serum samples were collected at the first visit and 30 days after vaccination and tested for SARS-CoV-2 S1 serology with Ortho total IgG anti-S1 protein and Cpass, an ACE2 receptor binding domain inhibition assay. Only one child had a mild symptom after vaccination, with no other adverse events documented up to the 30 days follow-up. Of 27 children tested 3-9 days after vaccination, 5 (19%) had positive serology suggesting a previous natural SARS-CoV-2 infection, with all 19 tested on day 30 after vaccination and presenting with positive tests, with an increment of antibody titers in those initially positive. A low Cpass binding inhibition was observed in the first collection in 11 seronegative cases, with high titers among those anti-S1 positive. All children showed an important increase in antibody titers on day 30. The event allowed the documentation of a robust serological response to one dose of CoronaVac in this small population of young children, with no major adverse effects. Although it was an unfortunate accident, this event may contribute with future vaccine strategies in this age group. The data suggest that CoronaVac is safe and immunogenic for children.

RESUMO Em fevereiro de 2020, um navio de carga vindo da China atracou no Porto de Santos com relato de tripulantes com quadro febril e respiratório. Uma equipe foi mobilizada para verificar a existência de casos suspeitos de COVID-19 dentro da embarcação e definir a liberação da embarcação no porto. Todos os 25 tripulantes foram entrevistados e não foram encontrados casos suspeitos. Então a embarcação foi liberada para atividades no porto. A investigação resultou da aplicação do plano de contingência diante de uma emergência de saúde pública de importância internacional e houve a colaboração de diversas entidades de vigilância.

ABSTRACT In February 2020, a Chinese cargo ship docked at the Port of Santos with reports of crew members with a feverish and respiratory condition. A team was gathered to verify the existence of suspected cases of COVID-19 inside the vessel and define its clearance. All 25 crew members were interviewed, and no suspected cases were found. The vessel was then cleared for port activities. The investigation resulted from the implementation of the contingency plan to face a public health emergency of international importance and several surveillance entities cooperated.

RESUMO Em fevereiro de 2020, um navio de carga vindo da China atracou no Porto de Santos com relato de tripulantes com quadro febril e respiratório. Uma equipe foi mobilizada para verificar a existência de casos suspeitos de COVID-19 dentro da embarcação e definir a liberação da embarcação no porto. Todos os 25 tripulantes foram entrevistados e não foram encontrados casos suspeitos. Então a embarcação foi liberada para atividades no porto. A investigação resultou da aplicação do plano de contingência diante de uma emergência de saúde pública de importância internacional e houve a colaboração de diversas entidades de vigilância.

ABSTRACT In February 2020, a Chinese cargo ship docked at the Port of Santos with reports of crew members with a feverish and respiratory condition. A team was gathered to verify the existence of suspected cases of COVID-19 inside the vessel and define its clearance. All 25 crew members were interviewed, and no suspected cases were found. The vessel was then cleared for port activities. The investigation resulted from the implementation of the contingency plan to face a public health emergency of international importance and several surveillance entities cooperated.

Resumo Objetivo: descrever a ocorrência da hepatite B entre gestantes, a realização de imunoprofilaxia e a transmissão vertical e perinatal nas crianças expostas ao vírus na rede de Atenção Primária à Saúde do estado de São Paulo, Brasil. Métodos: estudo transversal sobre registros de pré-natal de gestantes atendidas de janeiro a junho de 2012 e coorte dos recém-nascidos; foram descritas as frequências dos resultados e calculada a estimativa da ocorrência da hepatite B. Resultados: foram incluídas 6.233 gestantes, das quais 53,1% com 20 a 29 anos de idade, 58,7% com 8 a 11 anos de estudo, 53,3% brancas e 73,9% com companheiro; a ocorrência de hepatite B foi de 0,13% (IC95%: 0,04 a 0,21%); das oito crianças de mães com hepatite B crônica, seis tiveram esquema vacinal completo e não houve transmissão vertical ou perinatal. Conclusão: observou-se baixa ocorrência de hepatite B em gestantes e ausência de transmissão vertical ou perinatal.

Abstract Objective: to describe the occurrence of hepatitis B among pregnant women, immunoprophylaxis and vertical and perinatal transmission in children exposed to the virus in the São Paulo state primary care network, Brazil. Methods: this was a cross-sectional study using prenatal records of pregnant women attending health services between January and June 2012 and a cohort of newborns; the frequencies of the results were described and the estimated occurrence of hepatitis B was calculated. Results: 6,233 pregnant women were included, of whom 53.1% were between 20-29 years old, 58.7% had 8-11 years of schooling, 53.3% were white, and 73.9% lived with a partner; occurrence of hepatitis B was 0.13% (95%CI 0.04; 0.21); of the eight children of mothers with chronic hepatitis B, six had a complete vaccination schedule, and there was no vertical or perinatal transmission. Conclusion: there was low occurrence of hepatitis B in pregnant women and absence of vertical or perinatal transmission.

Resumen Objetivo: describir el aparecimiento de hepatitis B en mujeres embarazadas, la inmunoprofilaxis y la transmisión vertical y perinatal en niños expuestos al virus en la red de atención primaria en el estado de São Paulo, Brasil. Métodos: estudio transversal con registros prenatales de mujeres embarazadas atendidas de enero a junio de 2012 y cohorte de recién nacidos; se describieron las frecuencias y se calculó el surgimiento de la hepatitis B. Resultados: se incluyeron 6.233 gestantes, de las cuales 53,1% con 20 a 29 años de edad, 58,7% con 8 a 11 años de estudios, 53,3% blancas y 73,9% viviendo en pareja; la ocurrencia de hepatitis B fue del 0,13% (IC95%: 0,04 to 0,21%); entre ocho hijos de madres con hepatitis B crónica, seis tenía un calendario de vacunación completo y no había transmisión vertical o perinatal. Conclusión: hubo baja ocurrencia de hepatitis B en mujeres embarazadas y ausencia de transmisión vertical o perinatal.

Resumo 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.

Abstract 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.

Resumen 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.

Resumo Objetivo: descrever a ocorrência da hepatite B entre gestantes, a realização de imunoprofilaxia e a transmissão vertical e perinatal nas crianças expostas ao vírus na rede de Atenção Primária à Saúde do estado de São Paulo, Brasil. Métodos: estudo transversal sobre registros de pré-natal de gestantes atendidas de janeiro a junho de 2012 e coorte dos recém-nascidos; foram descritas as frequências dos resultados e calculada a estimativa da ocorrência da hepatite B. Resultados: foram incluídas 6.233 gestantes, das quais 53,1% com 20 a 29 anos de idade, 58,7% com 8 a 11 anos de estudo, 53,3% brancas e 73,9% com companheiro; a ocorrência de hepatite B foi de 0,13% (IC95%: 0,04 a 0,21%); das oito crianças de mães com hepatite B crônica, seis tiveram esquema vacinal completo e não houve transmissão vertical ou perinatal. Conclusão: observou-se baixa ocorrência de hepatite B em gestantes e ausência de transmissão vertical ou perinatal.

Abstract Objective: to describe the occurrence of hepatitis B among pregnant women, immunoprophylaxis and vertical and perinatal transmission in children exposed to the virus in the São Paulo state primary care network, Brazil. Methods: this was a cross-sectional study using prenatal records of pregnant women attending health services between January and June 2012 and a cohort of newborns; the frequencies of the results were described and the estimated occurrence of hepatitis B was calculated. Results: 6,233 pregnant women were included, of whom 53.1% were between 20-29 years old, 58.7% had 8-11 years of schooling, 53.3% were white, and 73.9% lived with a partner; occurrence of hepatitis B was 0.13% (95%CI 0.04; 0.21); of the eight children of mothers with chronic hepatitis B, six had a complete vaccination schedule, and there was no vertical or perinatal transmission. Conclusion: there was low occurrence of hepatitis B in pregnant women and absence of vertical or perinatal transmission.

Resumen Objetivo: describir el aparecimiento de hepatitis B en mujeres embarazadas, la inmunoprofilaxis y la transmisión vertical y perinatal en niños expuestos al virus en la red de atención primaria en el estado de São Paulo, Brasil. Métodos: estudio transversal con registros prenatales de mujeres embarazadas atendidas de enero a junio de 2012 y cohorte de recién nacidos; se describieron las frecuencias y se calculó el surgimiento de la hepatitis B. Resultados: se incluyeron 6.233 gestantes, de las cuales 53,1% con 20 a 29 años de edad, 58,7% con 8 a 11 años de estudios, 53,3% blancas y 73,9% viviendo en pareja; la ocurrencia de hepatitis B fue del 0,13% (IC95%: 0,04 to 0,21%); entre ocho hijos de madres con hepatitis B crónica, seis tenía un calendario de vacunación completo y no había transmisión vertical o perinatal. Conclusión: hubo baja ocurrencia de hepatitis B en mujeres embarazadas y ausencia de transmisión vertical o perinatal.

Resumo 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.

Abstract 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.

Resumen 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.

ABSTRACT Eleven lactating women were inadvertently vaccinated with 17DD yellow fever vaccine in a small city of Sao Paulo State, Brazil. Their infants were being exclusively breast-fed and the breastfeeding was interrupted for 10 days. Serum and breastmilk were collected from the vaccinated mothers and tested for the presence of genomic RNA of the vaccine strain 8, 10 and 15 days after vaccination. Viral RNA was not detected in any of the serum and human milk samples tested and the infants remained asymptomatic. Our result strengthens the effectineness of stopping breastfeeding for 10 days after the inadvertent yellow fever vaccination of lactating women.

ABSTRACT In March 2014, the Quadrivalent human papilloma virus vaccine (4vHPV) was introduced in the female adolescents vaccination schedule of the National Immunization Program (PNI). A school-based vaccination program was implemented. We conducted a retrospective, descriptive study of the adverse events that took place after HPV vaccination, reported to the Adverse Events Following Immunization (AEFI) Information System in Sao Paulo State, from March 2014 to December 2016. All reports that fit the definitions of the 2014 National Manual on AEFI surveillance were included. AEFI risk was estimated by dividing the number of reports by the number of vaccine doses administered in the period. In the three-year period, 3,390,376 HPV vaccine doses were administered and 465 AEFI reports were registered, with 1,378 signs and symptoms. The reporting rate was 13.72 per 100,000 vaccine doses administered. The reports peaked in the first year of the program. The most frequent AEFI was syncope, with 5.7 reports per 100,000 doses administered, followed by dizziness, malaise, headache and nausea. Overall, 39 AEFI cases (8.4%) were classified as severe , with a reporting rate of 1.15 per 100,000 vaccine doses administered. Most cases were classified as severe because of hospitalization. Among them, there were cases of Guillain-Barré Syndrome, deep vein thrombosis, seizures and miscarriage. All young women recovered without sequelae. We identified five clusters of AEFI reports in four cities; the larger AEFI cluster occurred in the city of Bertioga, in September 2014, involving 13 female adolescents. Our data are in accordance with those from other countries and corroborate the safety of HPV vaccines.

Abstract INTRODUCTION: The state of São Paulo has been monitoring cases of microcephaly and pregnant women presenting with acute rash, through CeVeSP. METHODS: This was a descriptive study focusing on pregnant women with rash and the outcome of their pregnancy, based on the notifications through the CeVeSP. RESULTS: During 2016, 2,209 cases of pregnant women with rash were reported and investigated. Of these, 36.6% were confirmed. Of the pregnant women who tested positive for ZIKV, 6.4% did not have a favorable outcome. CONCLUSIONS Our results allowed the characterization of pregnant women exposed to ZIKV and the outcome of pregnancy.

Resumo Objetivo: caracterizar os casos de síndrome congênita associada à infecção pelo ZIKV (SCZ) e outras etiologias infeciosas, residentes no estado de São Paulo, Brasil, no período de 30 de outubro de 2015 a 30 de junho de 2017. Métodos: estudo descritivo dos casos suspeitos de SCZ e outras etiologias infecciosas notificados no Registro de Eventos em Saúde Pública. Resultados: foram investigados 960 casos até a semana epidemiológica 26/2017, sendo confirmados 146 para infecção congênita; destes, 59 (40,4%) foram confirmados para infecção congênita sem identificação etiológica e 87 (59,6%) com confirmação laboratorial, sendo 55 com SCZ e 32 com síndrome congênita associada a outros agentes infecciosos. Conclusão: este estudo permitiu detectar 23,9% de casos de SCZ entre os casos suspeitos de etiologia infecciosa.

Abstract Objective: to characterize cases of congenital syndrome associated with Zika virus infection (CZS) and other infectious etiologies, resident in the state of São Paulo, Brazil, from October 30, 2015, to June 30, 2017. Methods: this was a descriptive study of suspected cases of CZS and other infectious etiologies notified on the Public Health Events Registry. Results: 960 cases were investigated up to epidemiological week 26/2017, and 146 were confirmed for congenital infection; of these, 59 (40.4%) were confirmed for congenital infection without etiological identification and 87 (59.6%) with laboratory confirmation, of which 55 were congenital syndrome associated with Zika virus and 32 were congenital syndrome associated with other infectious agents. Conclusion: this study enabled the detection of 23.9% CZS cases among suspected cases of infectious etiology.

Resumen Objetivo: caracterizar los casos sospechosos de síndrome congénita asociada a la infección por virus Zika (SCZ) y otras etiologías infecciosas residentes en el estado de São Paulo, Brasil, en el período de 30 de octubre de 2015 a 30 de junio de 2017. Métodos: estudio descriptivo de los casos sospechosos de síndrome congénita asociada a la infección por el virus Zika y otras etiologías infecciosas notificadas en el Registro de Eventos en Salud Pública. Resultados: se han investigado 960 casos hasta la semana epidemiológica 26/2017, siendo confirmados 146 para la infección congénita; de estos, 59 fueron confirmados para infección congénita sin identificación etiológica y 87 con identificación etiológica, siendo 55 síndrome congénita asociados al virus Zika y 32 síndrome congénita asociado a otros agentes infecciosos. Conclusión: este estudio permitió detectar una tasa del 23,9% de casos de SCZ entre los casos sospechosos de etiología infecciosa.

Resumo Objetivo: caracterizar os casos de síndrome congênita associada à infecção pelo ZIKV (SCZ) e outras etiologias infeciosas, residentes no estado de São Paulo, Brasil, no período de 30 de outubro de 2015 a 30 de junho de 2017. Métodos: estudo descritivo dos casos suspeitos de SCZ e outras etiologias infecciosas notificados no Registro de Eventos em Saúde Pública. Resultados: foram investigados 960 casos até a semana epidemiológica 26/2017, sendo confirmados 146 para infecção congênita; destes, 59 (40,4%) foram confirmados para infecção congênita sem identificação etiológica e 87 (59,6%) com confirmação laboratorial, sendo 55 com SCZ e 32 com síndrome congênita associada a outros agentes infecciosos. Conclusão: este estudo permitiu detectar 23,9% de casos de SCZ entre os casos suspeitos de etiologia infecciosa.

Abstract Objective: to characterize cases of congenital syndrome associated with Zika virus infection (CZS) and other infectious etiologies, resident in the state of São Paulo, Brazil, from October 30, 2015, to June 30, 2017. Methods: this was a descriptive study of suspected cases of CZS and other infectious etiologies notified on the Public Health Events Registry. Results: 960 cases were investigated up to epidemiological week 26/2017, and 146 were confirmed for congenital infection; of these, 59 (40.4%) were confirmed for congenital infection without etiological identification and 87 (59.6%) with laboratory confirmation, of which 55 were congenital syndrome associated with Zika virus and 32 were congenital syndrome associated with other infectious agents. Conclusion: this study enabled the detection of 23.9% CZS cases among suspected cases of infectious etiology.

Resumen Objetivo: caracterizar los casos sospechosos de síndrome congénita asociada a la infección por virus Zika (SCZ) y otras etiologías infecciosas residentes en el estado de São Paulo, Brasil, en el período de 30 de octubre de 2015 a 30 de junio de 2017. Métodos: estudio descriptivo de los casos sospechosos de síndrome congénita asociada a la infección por el virus Zika y otras etiologías infecciosas notificadas en el Registro de Eventos en Salud Pública. Resultados: se han investigado 960 casos hasta la semana epidemiológica 26/2017, siendo confirmados 146 para la infección congénita; de estos, 59 fueron confirmados para infección congénita sin identificación etiológica y 87 con identificación etiológica, siendo 55 síndrome congénita asociados al virus Zika y 32 síndrome congénita asociado a otros agentes infecciosos. Conclusión: este estudio permitió detectar una tasa del 23,9% de casos de SCZ entre los casos sospechosos de etiología infecciosa.

Resumo Objetivo: A vigilância da intussuscepção foi iniciada após a introdução da vacina monovalente viva atenuada contra rotavírus (RV1) em todo o país. O objetivo é avaliar a epidemiologia da intussuscepção e comparar a quantidade de casos antes e depois da introdução da vacina contra rotavírus. Métodos: Os casos de intussuscepção entre março de 2006 e janeiro de 2008 foram identificados por meio de um sistema de vigilância passivo prospectivo aprimorado estabelecido em hospitais-sentinela estaduais. A análise retrospectiva de prontuários médicos foi usada para identificar os casos que ocorreram em hospitais-sentinela entre janeiro de 2001 e fevereiro de 2006. Resultados: De 2001-2008, identificamos 331 casos de intussuscepção, 59,5% dos quais ocorreram em pacientes do sexo masculino, com pico de incidência entre aqueles com 18-24 semanas de idade. Em geral, < 10% dos casos ocorreram entre neonatos com 6-14 semanas de idade (quando a 1a dose de RV1 é administrada). Os sinais ou sintomas de intussuscepção observados com mais frequência incluíam vômito (89,4%), fezes com sangue (75,5%) e distensão abdominal (71,8%). A maioria (92,1%) dos pacientes precisou de cirurgia para o tratamento; 31,8% dos que se submeteram à cirurgia precisaram de ressecção intestinal e 13 (3,9%) vieram a óbito. Entre os 21 hospitais que relataram casos durante todo o período de vigilância (2001-2008), a quantidade de casos de intussuscepção em 2007 (n = 26) e 2008 (n = 19) não foi maior do que a quantidade média anual (31, faixa de 24-42) durante os anos-base de 2001-2005. Conclusões: Embora esta análise não tenha identificado um aumento nos casos de intussuscepção nos dois anos após a introdução da RV1, esses resultados justificam a necessidade de métodos epidemiológicos especiais para avaliar a possível associação entre a vacina contra rotavírus e esse evento adverso muito raro.

Abstract Objective: Intussusception surveillance was initiated after the nationwide introduction of live attenuated monovalent rotavirus vaccine (RV1). The objective is to assess the epidemiology of intussusception and compare the number of cases before and after the introduction of rotavirus vaccine. Methods: Cases of intussusception occurring between March 2006 and January 2008 were identified through a prospective enhanced passive surveillance system established in sentinel state hospitals. Retrospective review of medical records was used to identify cases, which occurred in sentinel hospitals between January 2001 and February 2006. Results: From 2001 to 2008, 331 intussusception cases were identified, 59.5% were male, with peak incidence among those 18–24 weeks of age. Overall <10% of cases were among infants 6–14 weeks of age (when the first dose of RV1 is administered). The most frequently observed signs or symptoms of intussusception included vomiting (89.4%), bloody stool (75.5%), and abdominal distention (71.8%). A majority (92.1%) of the case-patients required surgery for treatment; 31.8% of those who underwent surgery required bowel resection, and 13 (3.9%) died. Among the 21 hospitals that reported cases throughout the entire surveillance period (2001–2008), the number of intussusception events during 2007 (n = 26) and 2008 (n = 19) was not greater than the average annual number (n = 31, range 24–42) during baseline years 2001–2005. Conclusions: Although this analysis did not identify an increase in intussusception cases during the two years after RV1 introduction, these results support the need for special epidemiologic methods to assess the potential link between rotavirus vaccine and this very rare adverse event.

The aim of the present study was to assess the prevalence of Haemophilus influenzaetype b (Hib) nasopharyngeal (NP) colonisation among healthy children where Hib vaccination using a 3p+0 dosing schedule has been routinely administered for 10 years with sustained coverage (> 90%). NP swabs were collected from 2,558 children who had received the Hib vaccine, of whom 1,379 were 12-< 24 months (m) old and 1,179 were 48-< 60 m old. Hi strains were identified by molecular methods. Hi carriage prevalence was 45.1% (1,153/2,558) and the prevalence in the 12-< 24 m and 48-< 60 m age groups were 37.5% (517/1,379) and 53.9% (636/1,179), respectively. Hib was identified in 0.6% (16/2,558) of all children in the study, being 0.8% (11/1,379) and 0.4% (5/1,179) among the 12-< 24 m and 48-< 60 m age groups, respectively. The nonencapsulate Hi colonisation was 43% (n = 1,099) and was significantly more frequent at 48-< 60 m of age (51.6%, n = 608) compared with that at 12-< 24 m of age (35.6%, n = 491). The overall resistance rates to ampicillin and chloramphenicol were 16.5% and 3.7%, respectively; the co-resistance was detected in 2.6%. Our findings showed that the Hib carrier rate in healthy children under five years was very low after 10 years of the introduction of the Hib vaccine.

We propose a method to analyse the 2009 outbreak in the region of Botucatu in the state of São Paulo (SP), Brazil, when 28 yellow fever (YF) cases were confirmed, including 11 deaths. At the time of the outbreak, the Secretary of Health of the State of São Paulo vaccinated one million people, causing the death of five individuals, an unprecedented number of YF vaccine-induced fatalities. We apply a mathematical model described previously to optimise the proportion of people who should be vaccinated to minimise the total number of deaths. The model was used to calculate the optimum proportion that should be vaccinated in the remaining, vaccine-free regions of SP, considering the risk of vaccine-induced fatalities and the risk of YF outbreaks in these regions.