Outcome of Infants Born to Women with Chronic Hepatitis B: A Local Risk-Based Strategy in a Low Prevalence Country.

BACKGROUND: Chronic hepatitis-B virus (HBV) infection due to mother-to-child transmission (MTCT) during the perinatal period is an important global health concern. Chile is a low-prevalence country with an increasing migratory inflow from Latin- American countries, with intermediate to high endemic rates of HBV infection, and until 2021, there is no universal maternal screening. This study aimed to evaluate infant outcomes using a risk-based strategy of maternal screening to prevent MTCT of hepatitis B virus (HBV) in a low-prevalence country. METHODS: This prospective study included infants born to HBsAg-positive women detected using a local risk-based strategy. The exposed infants received immunoprophylaxis (IP) and follow-up to evaluate their clinical outcomes and immune responses through post-serological vaccine testing (PSVT) after completing the three- dose schedule of the HBV vaccine. RESULTS: A total of 99 HBsAg-positive mothers were detected. Seventy-six (82%) infants completed the follow-up and had PSVT between 9 and 12 months of age. 55.2% female, the median gestational age was 39 weeks (25-41) and the median birth weight was 3,130g (816-4,400 g). All patients received IP with recombinant HBV vaccine plus hepatitis-B virus immunoglobulin (HBIG) and three doses of the HBV vaccine. There were no cases of HBV infection, and 96% (72) responded to immunization with HBsAg antibodies (anti-HBsAg) >10 UI/ml, with a median level of 799 IU/ml. CONCLUSIONS: A high-risk strategy can be implemented in countries with non-universal screening for VHB. Timely IP plus high-uptake VHB vaccination in infants born to HBsAg-positive mothers was associated with a high immunogenic response and absence of MTCT.

[National action plan for the emergence of invasive meningococcal disease in Chile, 2012-2013]. / Plan de acción nacional frente a la emergencia de la cepa W-135 responsable de enfermedad meningocócica invasora en Chile, 2012-2013.

Invasive meningococcal disease is challenging for public health, mainly when it manifests with sudden changes in incidence, serogroups and hypervirulent clones that spread in the population, causing great alarm due to its sequelae and often fatal course, a situation that occurred in Chile, starting at week 26 of the year 2012. To face this scenario, an organization of multidisciplinary teams was required, called W-135 Action Plan in Chile, which included sanitary alerts, education, reinforcement of the epidemiological surveillance of suspicious cases, immediate diagnosis through state-of-the-art techniques, blocking of contacts, communication plans, and, from the 42nd week, ON the vaccination campaign was started for children aged from 9-months-old to less than 5 years of age. The vaccination strategy had a great impact on the decrease in incidence (1.3 to 0.1/100,000) and case fatality rate in the vaccinated population (23% to 0%), with a high safety profile, leading to its subsequent inclusion in the national immunization program. The ability to develop molecular, clinical and epidemiological studies allowed us to better understand the situation, supporting public health policy decisions for its control. The W-135 Action Plan implemented by the Ministry of Health in Chile, to manage the outbreak of meningococcal disease by Neisseria meningitidis serogroup W, demonstrated that the coordination of these efforts, through an organized Action Plan, allows the implementation of campaigns at the national level achieving high coverage of risk populations in short periods of time, generating a positive impact on the health of the population.

[Statement from the Immunization Committee of the Chilean Infectious Diseases Society in reference to vaccine refusal and mandatory policy on vaccination]. / Posición del Comité Consultivo de Inmunizaciones de la Sociedad Chilena de Infectología en relación a los cuestionamientos de las vacunas y su obligatoriedad.

Although vaccines have had a tremendous impact in public health they are questioned by certain groups that consider them unnecessary or unsafe and argue in favor of the right to decide to be vacci nated or not. However vaccines must have special considerations because unlike other medical deci sions, not vaccinating has consequences not only for the individual but also for other members of the community. Immunizing a high proportion of the population limits the circulation of an infectious agent attaining what is called community or herd immunity that protects the susceptible members of the group. For this reason many countries consider vaccination mandatory as a responsibility of every citizen. This committee agrees with this view but thinks other strategies should be implemented as well, such as special educational efforts for the public and parents addressing benefits and real risks of vaccinating. Also health care professionals should be trained in vaccines. The notification system for adverse events currently available should be improved and be more accessible. Persons truly affected by adverse events due to vaccination should receive on time responses and be offered psychological and financial support. Finally all stakeholders should make coordinated efforts to work together to deliver messages that answer concerns on vaccines and bring confidence back to the public.

[Impact of the 10-valent pneumococcal conjugate vaccine on the southern area of Santiago (Chile), 2009-2015Efeito da vacina pneumocócica 10-valente conjugada na região sul de Santiago, Chile, 2009-2015]. / Efecto de la vacuna antineumocócica conjugada 10-valente en el área sur de Santiago de Chile, 2009-2015.

OBJECTIVE: The objective of this study was to evaluate the impact of the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) on the incidence of invasive pneumococcal disease (IPD) and on community-acquired pneumonia (CAP) in hospitalized children under 5 years of age in the southern area of Santiago, Chile. METHODS: An ecological study was conducted on the incidence of IPD and CAP in children under age 5 in the southern area of Santiago (Chile) from 2009 to 2015. The information used was from bacteriology laboratories in four hospitals, the Chilean Institute of Health Public (ISP), and hospital discharge records. RESULTS: A total of 6,461 cases of CAP and 173 cases of IPD were confirmed by the ISP; 169 of these cases were diagnosed in the bacteriology laboratories of the hospitals included in the study. When the incidence of cases in 2010 was compared to 2011-2015, the incidence ratio (IR) of IPD declined 10% annually (p=0.026) and CAP declined by 8% in the same period (p<0.001). Days of hospitalization due to IPD were reduced by 39% (p<0.001). Between 2009 and 2012, seven children died, but since then there have been no deaths due to these diseases. CONCLUSIONS: The introduction of the PCV-10 vaccine into the National Immunization Program has had a positive effect, with a significant reduction in IPD and CAP and in days of hospitalization due to IPD, while preventing cases and deaths.

OBJETIVO: Avaliar o efeito da incorporação da vacina pneumocócica 10-valente (PCV 10) na incidência de doença pneumocócica invasiva (DPI) e pneumonia adquirida na comunidade (PAC) em crianças menores de cinco anos internadas em hospital. MÉTODOS: Foi realizado um estudo ecológico da incidência de DPI e PAC em crianças menores de cinco anos na região sul de Santiago, no Chile, de 2009 a 2015. As fontes de informação usadas foram os registros dos laboratórios de bacteriologia de quatro hospitais, dados do Instituto de Saúde Pública do Chile (ISP) e registros de altas hospitalares. RESULTADOS: Ao todo, 6.461 casos de PAC e 173 casos de DPI foram confirmados pelo ISP, dos quais 169 casos foram diagnosticados nos laboratórios de bacteriologia dos hospitais participantes do estudo. Ao comparar a incidência de casos entre 2010 e o período de 2011­2015, observou-se um declínio de 10% na taxa de incidência anual de DPI (p = 0,026) e de 8% na de PAC no mesmo período (p<0,001). Os dias de leito ocupado por DPI tiveram uma redução de 39% ao ano (p <0,001). Sete crianças morreram até 2012 e a partir daí não ocorreram mais mortes por estas doenças. CONCLUSÕES: A incorporação da vacina PCV-10 no programa nacional de vacinação surtiu um efeito positivo: houve uma redução significativa do número de casos de DPI e PAC e da ocupação de leitos por DPI e casos e mortes foram evitados.

[Pertussis vaccination in pregnancy: Security and effectiveness in the protection of the infant]. / Vacunación con pertussis en el embarazo: una estrategia segura y efectiva para proteger al lactante menor.

Whooping cough is an immune preventable disease that can be life threatening. Despite infant immunization starting at 2 month of age, there are many cases and outbreaks in our country and also around the world, with a high risk of mortality specially in infants under 6 month of age. It has been proposed that antenatal vaccination with acellular pertussis component (Tdap) would be useful, safe and effective since it transfers a high antibody rate to the child, reducing the incidence of pertussis in this group by 85%. No higher incidence of adverse effects has been found in pregnant women with this vaccine. This strategy has been implemented in several developed and Latin American countries. The purpose of this manuscript is to review and discuss the benefits of antenatal vaccination with Tdap. It was concluded that maternal immunization with Tdap vaccine should be promoted to prevent infection and associated mortality in the less than 6 months of age by Bordetella pertussis.

[Result of a model of management of special vaccines]. / Resultado de un modelo de gestión de vacunas especiales.

INTRODUCTION: Special vaccines recommendation patients are a growing population. The Ministry of Health has developed a special vaccination program for these cases, through which our hospital manages vaccine forms by an established flowchart. OBJECTIVE: To describe the special vaccines model of management results in the period between March 2015 and September 2016, and the clinical and demographics characterization of the pediatric population benefited with this program in Dr. Exe-quiel González Cortés Children's Hospital. PATIENTS AND METHODS: We performed a descriptive ob servational study, which covers the chronically ill patient's population who received special vaccines during the period between March 2015 to September 2016. RESULTS: A total of 367 vaccine schemes were administered to 215 patients, with a total of 405 vaccines administered during the period. The medical specialties that most requested vaccines were infectology (39.1%), immune-rheumatology (24.2%) and bronchopulmonary specialists (20%). The National Immunization Program authorized 97.8% of the requested schemes (n = 359), the response time had a median of 15 days (range 0-174 days), the vaccination opportunity had a median of 41 days (range 0-287 days) and the total of sche mes completed at the time of tabulating the results was 52.8%. CONCLUSIONS: Vaccines are one of the main public health equity policies and Chile has special vaccines request flowchart a flow chart, which requires a multidisciplinary work to provide coverage to this vulnerable child population.

[Seroconversion in response to a reinforced primary hepatitis B vaccination in children with cancer]. / Seroconversión frente a primovacunación reforzada contra hepatitis B en niños con cáncer.

INTRODUCTION: Immune response against vaccine antigens may be impaired in children with cancer. The aim of this study was to evaluate the seroconversion response against hepatitis B vaccination (HBV) at the time of chemotherapy onset and/or remission in children with cancer. PATIENTS AND METHOD: Prospective, two-centre, controlled, non-randomised study conducted on children recently diagnosed with cancer, paired with healthy subjects. Cases received HBV at time 0, 1 and 6 months with DNA recombinant HBV at a dose of 20 and 40 µg if < or > than 10 years of age, respectively, at the time of diagnosis for solids tumours and after the remission in case of haematological tumours. Controls received the same schedule, but at of 10 and 20 µg doses, respectively. HBs antibodies were measured in serum samples obtained at 2, 8 and 12 months post-vaccination. Protective titres were defined as > 10 mIU/ml at 8th month of follow up. RESULTS: A total of 78 children with cancer and 25 healthy controls were analysed at month 8th of follow up. Seroconversion rates in the cancer group reached 26.9%, with no differences by age, gender or type of tumour (P = .13, .29, and .44, respectively). Control group seroconversion was 100% at the 8th month, with P < .0001 compared with the cancer group. At month 12 of follow up, just 31.9% of children with cancer achieved anti-HBs antibodies > 10 mIU/ml. CONCLUSIONS: Vaccination against hepatitis B with three doses of DNA recombinant vaccine at an increased concentration, administrated at the time of onset of chemotherapy and/or remission provided an insufficient immune response in a majority of children with cancer. More immunogenic vaccines should be evaluated in this special population, such as a third generation, with more immunogenic adjuvants, enhanced schedules at 0, 1, 2, 6 month, evaluation of antibody titres at month 8 and 12h to evaluate the need for further booster doses.

[Therapeutic monitoring of intravenous vancomycin in a pediatric critical care unit]. / Monitoreo terapéutico de vancomicina intravenosa en una unidad de paciente crítico pediátrico.

BACKGROUND: In critically ill pediatric patients vancomycin distribution and elimination is altered underscoring the need for pharmacokinetic monitoring; however the therapeutic trough ranges have not been validated for children. OBJECTIVE: To describe the pharmacokinetics of intravenous vancomycin in critically ill pediatric patients using plasmatic vancomycin monitoring. METHODS: Retrospective, descriptive study performed in a paediatric critical care unit. Vancomycin serum levels (Cmin and Cpeak), t ½ and Vd were determined in 1 month to 12 year old patients receiving ≥ 40 mg per-kg-per day. Plasmatic levels were measured at therapy onset and during follow up, evaluating the proportion of trough level determinations within therapeutic range, the average trough concentration, and the Cpeak achieved. RESULTS: A total of 65 plasmatic vancomycin monitorings were analysed in 45 patients. The average values for Ctrough, Cpeak, t1/2 and Vd were 10.4 µg/mL, 22.7 µg/mL, 3,1 h and 0.7 L/kg, respectively. An average dose of 47,1 mg/kg/day achieved initial Ctrough levels < 10 mg/mL in 60% of patients (n = 27), between 10 and 14,9 µg/mL in 22,2% (n = 10), between 15 to 20 µg/mL in 4% (n: 2), and > 20 µg/mL in 13,3% (n: 6). CONCLUSIONS: Vancomycin doses of 40 mg/kg/day are insufficient for critically ill paediatric patients without renal failure. A higher starting dose and monitoring of plasma levels must be considered in this population.

Real-world impact and effectiveness of MenACWY-TT.

In response to escalating cases of serogroup W (MenW) invasive meningococcal disease (IMD), multiple countries introduced quadrivalent conjugate MenACWY vaccines into their national immunization programs (NIPs). Here, we summarize the real-world impact and vaccine effectiveness (VE) data of MenACWY-TT from Chile, England, the Netherlands, and Australia. Incidence rate reductions (IRRs) and VE from baseline to post-NIP period were extracted from publications or calculated. After the administration of a single dose of MenACWY-TT, substantial IRRs of MenCWY were observed across the countries in vaccine-eligible age groups (83%-85%) and via indirect protection in non-vaccine-eligible age groups (45%-53%). The impact of MenACWY-TT was primarily driven by MenW IRRs, as seen in vaccine-eligible age groups (65%-92%) and non-vaccine-eligible age groups (41%-57%). VE against MenW was reported in vaccine-eligible toddlers (92%) in the Netherlands and in vaccine-eligible adolescents/young adults (94%) in England. These real-world data support the implementation and continued use of MenACWY-TT in NIPs.

Hypervirulent Strains of Neisseria meningitidis and Clinical Manifestations in Children With Invasive Meningococcal Disease.

BACKGROUND: Hypervirulent clonal complex (cc) have been associated with higher incidence and case fatality rate of invasive meningococcal disease (IMD). The aim of this study was to describe the clinical manifestations of the hypervirulent cc of meningococcus in children. METHODS: Retrospective study in patients hospitalized by IMD microbiologically confirmed at three children's tertiary health care centers in Santiago, Chile, between 2010 and 2018. Demographic, clinical information and determination of the cc and factor H binding protein (fHbp) alleles were performed. RESULTS: In total 93 cases were evaluated, sequence typing was available for 91 cases, and 87 (95.6%) had a cc assigned; 63.7% were MenW and 31.8% MenB. The median age was 9 months, 67% were male and 18.7% had any comorbidity. A 26.4% presented neurological deficit, 25.3% petechiae and 20% diarrhea. Sixty-seven percent were admitted to the pediatric intensive care unit (PICU) and the case fatality rate was 9.9%. Regarding cc and fHbp alleles, ST11, ST41/44 and allele 22 were the most frequently identified, with 63.7%, 19.8% and 72.5%, respectively. We found statistically significant differences between the cc and presence of petechiae, diagnosis of meningococcemia plus meningitis, admission and days in PICU and advanced support. Allele 22 for fHbp was associated with the absence of petechiae, low suspicion of IMD, less diagnosis of meningitis+meningococcemia, PICU admission, advanced support and adrenal insufficiency. CONCLUSION: Epidemiological and microbiological surveillance of IMD should integrate clinical and laboratory components, including molecular and genetic characterization, to enrich the dynamic understanding of the clinical evolution of IMD.

Epidemiology of Meningococcal Disease in Four South American Countries and Rationale of Vaccination in Adolescents from the Region: Position Paper of the Latin American Society of Pediatric Infectious Diseases (SLIPE).

Surveillance of meningococcal disease (MD) is crucial after the implementation of vaccination strategies to monitor their impact on disease burden. Adolescent vaccination could provide direct and indirect protection. Argentina, Brazil, and Chile have introduced meningococcal conjugate vaccines (MCV) into their National Immunization Programs (NIP), while Uruguay has not. Here, we analyze the epidemiology of MD and vaccination experience from these four South American countries to identify needs and plans to improve the current vaccination programs. METHODOLOGY: Descriptive study of MD incidence rates, serogroup distribution, case fatality rates (CFR), and MCV uptakes during the period 2010-2021 in Argentina, Brazil, Chile, and Uruguay. Data were extracted from national surveillance programs, reference laboratories, NIPs, and Pubmed. RESULTS: MD overall incidence from 2010 to 2021 have a decreasing trend in Argentina (0.37 [IQR = 0.20-0.61]), Brazil (0.59 [IQR = 0.54-1.22]), and Chile (0.45 [IQR = 0.40-0.77]), while a significant increase in Uruguay (0.47 [IQR = 0.33-0.69]) was found from 2016 to 2019. During the COVID-19 pandemic, all countries sharply reduced their MD incidence. The highest incidence rates were observed among infants, followed by children 1-4 years of age. No second peak was evident in adolescents. A reduction in serogroup C, W, and Y cases has occurred in Argentina, Brazil, and Chile after introduction of MCV, serogroup B becoming predominant in all four countries. Median CFR was 9.0%, 21%, 19.9%, and 17.9% in Argentina, Brazil, Chile, and Uruguay, respectively. Median uptake of MCV for Argentina and Brazil were 66.6% and 91.0% for priming in infants; 54.7% and 84.5% for booster in toddlers; and 47.5% and 53% for adolescents; while for Chile, 95.6% for toddlers. CONCLUSIONS: Experience after the implementation of MCV programs in South America was successful, reducing the burden of MD due to the vaccine serogroups. High vaccine uptake and the inclusion of adolescents will be crucial in the post-pandemic period to maintain the protection of the population. The increase in the proportion of serogroup B cases emphasizes the importance of continuous surveillance to guide future vaccination strategies.

Different Safety Pattern of an Inactivated SARS-CoV-2 Vaccine (CoronaVac®) According to Age Group in a Pediatric Population from 3 to 17 Years Old, in an Open-Label Study in Chile.

During the COVID-19 pandemic, the importance of vaccinating children against SARS-CoV-2 was rapidly established. This study describes the safety of CoronaVac® in children and adolescents between 3- and 17-years-old in a multicenter study in Chile with two vaccine doses in a 4-week interval. For all participants, immediate adverse events (AEs), serious AEs (SAEs), and AEs of special interest (AESIs) were registered throughout the study. In the safety subgroup, AEs were recorded 28 days after each dose. COVID-19 surveillance was performed throughout the study. A total of 1139 individuals received the first and 1102 the second dose of CoronaVac®; 835 were in the safety subgroup. The first dose showed the highest number of AEs: up to 22.2% of participants reported any local and 17.1% systemic AE. AEs were more frequent in adolescents after the first dose, were transient, and mainly mild. Pain at the inoculation site was the most frequent AE for all ages. Fever was the most frequent systemic AE for 3-5 years old and headache in 6-17 years old. No SAEs or AESIs related to vaccination occurred. Most of the COVID-19 cases were mild and managed as outpatients. CoronaVac® was safe and well tolerated in children and adolescents, with different safety patterns according to age.

Inactivated Vaccine-Induced SARS-CoV-2 Variant-Specific Immunity in Children.

Multiple vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been evaluated in clinical trials. However, trials addressing the immune response in the pediatric population are scarce. The inactivated vaccine CoronaVac has been shown to be safe and immunogenic in a phase 1/2 clinical trial in a pediatric cohort in China. Here, we report interim safety and immunogenicity results of a phase 3 clinical trial for CoronaVac in healthy children and adolescents in Chile. Participants 3 to 17 years old received two doses of CoronaVac in a 4-week interval until 31 December 2021. Local and systemic adverse reactions were registered for volunteers who received one or two doses of CoronaVac. Whole-blood samples were collected from a subgroup of 148 participants for humoral and cellular immunity analyses. The main adverse reaction reported after the first and second doses was pain at the injection site. Four weeks after the second dose, an increase in neutralizing antibody titer was observed in subjects relative to their baseline visit. Similar results were found for activation of specific CD4+ T cells. Neutralizing antibodies were identified against the Delta and Omicron variants. However, these titers were lower than those for the D614G strain. Importantly, comparable CD4+ T cell responses were detected against these variants of concern. Therefore, CoronaVac is safe and immunogenic in subjects 3 to 17 years old, inducing neutralizing antibody secretion and activating CD4+ T cells against SARS-CoV-2 and its variants. (This study has been registered at ClinicalTrials.gov under no. NCT04992260.) IMPORTANCE This work evaluated the immune response induced by two doses of CoronaVac separated by 4 weeks in healthy children and adolescents in Chile. To date, few studies have described the effects of CoronaVac in the pediatric population. Therefore, it is essential to generate knowledge regarding the protection of vaccines in this population. Along these lines, we reported the anti-S humoral response and cellular immune response to several SARS-CoV-2 proteins that have been published and recently studied. Here, we show that a vaccination schedule consisting of two doses separated by 4 weeks induces the secretion of neutralizing antibodies against SARS-CoV-2. Furthermore, CoronaVac induces the activation of CD4+ T cells upon stimulation with peptides from the proteome of SARS-CoV-2. These results indicate that, even though the neutralizing antibody response induced by vaccination decreases against the Delta and Omicron variants, the cellular response against these variants is comparable to the response against the ancestral strain D614G, even being significantly higher against Omicron.

Global epidemiology of serogroup B meningococcal disease and opportunities for prevention with novel recombinant protein vaccines.

BACKGROUND: Meningococcal disease (MD) is a major cause of meningitis and sepsis worldwide, with a high case fatality rate and frequent sequelae. Neisseria meningitidis serogroups A, B, C, W, X and Y are responsible for most of these life-threatening infections, and its unpredictable epidemiology can cause outbreaks in communities, with significant health, social and economic impact. Currently, serogroup B is the main cause of MD in Europe and North America and one of the most prevalent serogroups in Latin America. Mass vaccination strategies using polysaccharide vaccines have been deployed since the 1970s and the use of conjugate vaccines has controlled endemic and epidemic disease caused by serogroups A, C, W and Y and more recently serogroup B using geographically-specific outer membrane vesicle based vaccines. Two novel protein-based vaccines are a significant addition to our armamentarium against N. meningitidis as they provide broad coverage against highly diverse strains in serogroup B and other groups. Early safety, effectiveness and impact data of these vaccines are encouraging. These novel serogroup B vaccines should be actively considered for individuals at increased risk of disease and to control serogroup B outbreaks occurring in institutions or specific regions, as they are likely to save lives and prevent severe sequelae. Incorporation into national programs will require thorough country-specific analysis.

Experiencia chilena en el comportamiento del SARS-COV-2 y campaña de vacunación en pediatría / Chilean experience in the behavior of SARS-COV-2 and the vaccination in pediatrics

La pandemia por Covid-19 ha provocado millones de hospitalizaciones y muertes en el mundo, principalmente en la población adulta. A pesar de que la población pediátrica se ha visto afectada con una menor frecuencia y severidad que los adultos, no están exentos de casos prolongados, graves y letalidad, destacando la aparición de un nuevo cuadro clínico, como el síndrome inflamatorio multisistémico asociado a Covid-19. Constantes esfuerzos científicos han permitido avanzar de manera efectiva en la implementación de estrategias de vacunación pediátrica masiva contra el Covid-19. Actualmente, en Chile esta estrategia está demostrando ser segura, efectiva y puede colaborar con la reapertura de escuelas y el regreso a clases presenciales, de manera de disminuir las interrupciones y brechas escolares, otorgando otros beneficios indirectos, tales como el mejoramiento de la salud mental y emocional, el incremento de la actividad física y estabilidad familiar, aportando en el mejoramiento del bienestar y calidad de vida de los niños y sus familias.

The Covid-19 pandemic has caused millions of hospitalizations and deaths in the world, mainly in the adult population. Although the pediatric population has been affected less frequently and less severely than adults, they are not exempt from prolonged, severe cases and lethality by SARS-CoV-2, highlighting the appearance of a new clinical picture, such as multisystem inflammatory syndrome associated with Covid-19. Constant scientific efforts have made it possible to effectively advance in the implementation of mass pediatric vaccination strategies against Covid-19. Currently, in Chile this strategy is proving to be safe, effective and can collaborate with the school openings and returning to presential classes, to reduce interruptions and school-gaps, granting other indirect benefits, such as the improvement of mental and emotional health, the increase of physical activity and family stability, contributing to the improvement of the well-being and quality of life of children and their families.

[Statement of the Advisory Committee on Immunizations of Sociedad Chilena de Infectología about outbreaks of hepatitis A in Chile]. / Opinión del Comité Consultivo de Inmunizaciones de la Sociedad Chilena de Infectología en relación a los brotes de hepatitis A en Chile.

This document represents the position of the Chilean Infectious Diseases Society Advisory Committee on Immunization Practices regarding hepatitis A epidemiological situation in Chile. The recommendations are based on local epidemiological data, the hepatitis A virus infection characteristics and the global experience with the available vaccines. In relation to hepatitis A, Chile is no longer a highly endemic area but actually an intermediate one, currently concentrating cases in individuals over 15 years of age, with frequent outbreaks. In 2017 we have seen an important outbreak of genotype 1A in men who have sex with men (MSM). The current endemic, the presence of regular outbreaks, the frequency of natural disasters in Chile, together with the availability of safe, effective vaccines and local cost-effectiveness studies led us to propose measures for outbreak control for high risk groups protection and mid and long term, including a more definitive solution which is universal vaccination against this disease in small children.

[Statement from the Immunization Committee of the Chilean Infectious Diseases Society in reference to vaccine refusal and mandatory policy on vaccination]. / Declaración del Comité Consultivo de Inmunizaciones de Sociedad Chilena de Infectología en relación a los cuestionamientos de las vacunas y su obligatoriedad.

Although vaccines have had a tremendous impact in public health they are questioned by certain groups that consider them unnecessary or unsafe and argue in favor of the right to decide to be vaccinated or not. However vaccines must have special considerations because unlike other medical decisions, not vaccinating has consequences not only for the individual but also for other members of the community. Immunizing a high proportion of the population limits the circulation of an infectious agent attaining what is called herd immunity that protects the susceptible members of the group. For this reason many countries consider vaccination mandatory as a responsibility of every citizen. This committee agrees with this view but thinks other strategies should be implemented as well, such as special educational efforts for the public and parents addressing benefits and real risks of vaccinating. Also health care professionals should be trained in vaccines. The notification system for adverse events currently available should be improved and be more accessible. Persons truly affected by adverse events due to vaccination should receive on time responses and be offered psychological and financial support. Finally all stakeholders should make coordinated efforts to work together to deliver messages that answer concerns on vaccines and bring confidence back to the public.

[Meningococcal invasive disease caused by serogroup B in two Chilean children vaccinated against ACWY serogroups]. / Enfermedad meningocóccica invasora por serogrupo B en dos niños chilenos vacunados contra serogrupos ACWY.

Invasive meningococcal disease (IMD) by serogroup W has become predominant in Chile since 2012, prompting vaccination with conjugate ACWY. We reported two pediatric cases in patients already vaccinated, which evolved with IMD by serogroup B. This should remind us to keep the alertness with this pathology, despite the current vaccination system in Chile, emphasizing in improve our epidemiological case definition and its diagnosis.

Rotavirus Serum IgA Immune Response in Children Receiving Rotarix Coadministered With bOPV or IPV.

BACKGROUND: Vaccine schedules including bivalent oral and inactivated poliovirus vaccines will replace trivalent oral poliovirus vaccines in 2016. METHODS: We evaluated rotavirus immunoglobulin A seroresponses when the second dose of Rotarix at 16 weeks was given concomitantly with inactivated or bivalent oral poliovirus vaccines. RESULTS: Rotavirus immunoglobulin A seroresponse rate at week 28 was 15% lower in recipients of bivalent oral poliovirus vaccines compared with inactivated poliovirus vaccines. CONCLUSION: Bivalent oral poliovirus vaccine decreases rotavirus IgA seroresponse rates when coadministered at 16 weeks of age.

Vacunas en salud laboral: una oportunidad para prevenir e invertir en salud / Vaccines in occupational medicine: an opportunity to prevent and invest in health

La vacunación es la medida preventiva más costo-efectiva para evitar las enfermedades infecciosas inmunoprevenibles, a nivel individual y comunitario. Los riesgos biológicos laborales, deben ser manejados en un sistema de gestión del riesgo, donde la vacuna es el elemento clave de protección personal (EPP) específico cuya provisión y uso obligatorio tiene normas legislativas referidas a la entrega por el empleador, la capacitación en la prevención y el uso por el trabajador. En Chile, hay 8.364.282 trabajadores según datos de Superintendencia de Seguridad Social (SUSESO). La Ley 16.744 y sus Decretos Supremos (DS) indican las condiciones que se deben mantener en los lugares de trabajo y el derecho a saber por parte del trabajador; también existen circulares del Ministerio de Salud que incluyen situaciones y grupos especiales laborales a vacunar, pero es necesaria una normativa que oriente a trabajadores dependientes e independientes y a empleadores sobre qué vacunas colocar, en qué situaciones y a quiénes dependiendo de la actividad laboral. En este artículo, hacemos una reseña de la situación legal, de recomendaciones en otros países y enumeramos algunas vacunas que podrían implementarse en la población expuesta a riesgo.

Vaccination is the most cost-effective measure for immune-preventable infectious diseases, at individual and community level. Biological occupational hazards must be faced in a risk management system, where the vaccine is a specific key as an element of personal protection, whose provision and obligatory use has legislative norms related to the delivery by the employer, the training in the prevention and the use by the worker. Several countries count with technical guides for vaccination in the working population. In Chile in 2018, there were 8.364.282 workers according with Superintendence of Social Security. Law 16.744 and Supreme Decrees indicate the environmental conditions for workers and the right to know the risks; also, Ministry of Health has issued circulars where some working conditions need specific vaccination. Is for that reason that is necessary a regulation that guides dependent and independent workers and employers on when and which vaccines must be used depending on the labor activity. In this article, we review the legal situation, other guides in different countries and list some vaccines that could be implemented in the population at specifical risks.