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Effectiveness of an Inactivated SARS-CoV-2 Vaccine in Chile

2021 , Alejandro Jara , Eduardo A. Undurraga , Cecilia González , Fabio Paredes , Tomás Fontecilla , Gonzalo Jara , Alejandra Pizarro , ACEVEDO ROMO, JOHANNA PATRICIA , Katherinne Leo , Francisco Leon , Carlos Sans , Paulina Leighton , Pamela Suárez , Heriberto García-Escorza , ARAOS BRALIC, RAFAEL IGNACIO

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Effectiveness of CoronaVac in children 3–5 years of age during the SARS-CoV-2 Omicron outbreak in Chile

2022 , Alejandro Jara , Eduardo A. Undurraga , José R. Zubizarreta , Cecilia González , ACEVEDO ROMO, JOHANNA PATRICIA , Alejandra Pizarro , Verónica Vergara , Mario Soto-Marchant , Rosario Gilabert , Juan Carlos Flores , Pamela Suárez , Paulina Leighton , Pablo Eguiguren , Juan Carlos Ríos , Jorge Fernandez , Heriberto García-Escorza , ARAOS BRALIC, RAFAEL IGNACIO

AbstractThe outbreak of the B.1.1.529 lineage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Omicron) has caused an unprecedented number of Coronavirus Disease 2019 (COVID-19) cases, including pediatric hospital admissions. Policymakers urgently need evidence of vaccine effectiveness in children to balance the costs and benefits of vaccination campaigns, but, to date, the evidence is sparse. Leveraging a population-based cohort in Chile of 490,694 children aged 3–5 years, we estimated the effectiveness of administering a two-dose schedule, 28 days apart, of Sinovac’s inactivated SARS-CoV-2 vaccine (CoronaVac). We used inverse probability-weighted survival regression models to estimate hazard ratios of symptomatic COVID-19, hospitalization and admission to an intensive care unit (ICU) for children with complete immunization over non-vaccination, accounting for time-varying vaccination exposure and relevant confounders. The study was conducted between 6 December 2021 and 26 February 2022, during the Omicron outbreak in Chile. The estimated vaccine effectiveness was 38.2% (95% confidence interval (CI), 36.5–39.9) against symptomatic COVID-19, 64.6% (95% CI, 49.6–75.2) against hospitalization and 69.0% (95% CI, 18.6–88.2) against ICU admission. The effectiveness against symptomatic COVID-19 was modest; however, protection against severe disease was high. These results support vaccination of children aged 3–5 years to prevent severe illness and associated complications and highlight the importance of maintaining layered protections against SARS-CoV-2 infection.

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Estrategias y recomendaciones para enfrentar la enfermedad por virus respiratorio sincicial el año 2024

2024 , Enrique Paris , Paula Daza , Lorena Tapia , Juan Pablo Diaz , Pablo Cruces Romero , Andrés Castillo , Cecilia González , María Luz Endeiza , Leonor Jofré , Fabiola Castro , Alejandra Zamorano , Jaime Rodriguez , ACEVEDO ROMO, JOHANNA PATRICIA , Teresita Santa Cruz , Jaime González , Raúl Escárate , Juan Pablo Moreno , Paula Cisternas

Durante el invierno de 2023, Chile enfrentó una compleja situación relacionada con al virus respiratorio sincicial (VRS). Después de experimentar una disminución en la circulación del VRS durante los años de la pandemia de SARS-CoV-2, se observó un brote tardío en la primavera de 2022 y un inicio anticipado del brote en 2023, con un aumento significativo en el número de casos graves. La poca efectividad en la planificación estratégica y comunicación de riesgo contribuyeron a la complejidad de la situación. Para evitar lo anterior el próximo invierno, se sugieren medidas como vigilancia activa, unificación de definiciones para infecciones respiratorias agudas, identificación de variantes del VRS, educación pública sobre contagios y preparación anticipada respecto a camas hospitalarias y personal de salud. Se destaca la importancia de la inmunización y colaboración intersectorial para adquirir nuevas alternativas preventivas como también la necesidad de una comunicación temprana sobre la importancia de la inmunización e identificación de grupos de alto riesgo, mejora en capacitaciones del personal médico y planificación estratégica del Ministerio de Salud buscando un enfoque proactivo y colaborativo para abordar la compleja situación del VRS en futuros inviernos. El Comité Asesor en Vacunas y Estrategias de Inmunización de Chile ya realizó un análisis y recomendación sobre una nueva alternativa de prevención. Este grupo de trabajo apoyará cualquier decisión del Ministerio de Salud en políticas públicas que intenten un cambio en el paradigma del control de esta enfermedad por la salud de los niños/as de nuestro país. 

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Serological study of CoronaVac vaccine and booster doses in Chile: immunogenicity and persistence of anti-SARS-CoV-2 spike antibodies

2022 , Leonardo Vargas , Nicolás Valdivieso , Fabián Tempio , Valeska Simon , Daniela Sauma , Lucía Valenzuela , Caroll Beltrán , Loriana Castillo-Delgado , Ximena Contreras-Benavides , Mónica L. Acevedo , ACEVEDO ROMO, JOHANNA PATRICIA , Rafael I. Gonzalez , Fernando Valiente-Echeverría , Ricardo Soto-Rifo , Mario Rosemblatt , Mercedes Lopez , Fabiola Osorio , María Rosa Bono

Abstract Background Chile was severely affected by COVID19 outbreaks but was also one of the first countries to start a nationwide program to vaccinate against the disease. Furthermore, Chile became one of the fastest countries to inoculate a high percentage of the target population and implemented homologous and heterologous booster schemes in late 2021 to prevent potential immunological waning. The aim of this study is to compare the immunogenicity and time course of the humoral response elicited by the CoronaVac vaccine in combination with homologous versus heterologous boosters. Methods We compared the immunogenicity of two doses of CoronaVac and BNT162b2 vaccines and one homologous or heterologous booster through an ELISA assay directed against the ancestral spike protein of SARS-CoV-2. Sera were collected from individuals during the vaccination schedule and throughout the implementation of homologous and heterologous booster programs in Chile. Results Our findings demonstrate that a two-dose vaccination scheme with CoronaVac induces lower levels of anti-SARS-CoV-2 spike antibodies than BNT162b2 in a broad age range (median age 42 years; interquartile range (IQR) 27-61). Furthermore, antibody production declines with time in individuals vaccinated with CoronaVac and less noticeably, with BNT162b2. Analysis of booster schemes revealed that individuals vaccinated with two doses of CoronaVac generate immunological memory against the SARS-CoV-2 ancestral strain, which can be re-activated with homologous or heterologous (BNT162b2 and ChAdOx1) boosters. Nevertheless, the magnitude of the antibody response with the heterologous booster regime was considerably higher (induction fold BNT162b2: 11.2x; ChAdoX1; 12.4x; CoronaVac: 6.0x) than the responses induced by the homologous scheme. Both homologous and heterologous boosters induced persistent humoral responses (median 122 days, IQR (108-133)), although heterologous boosters remained superior in activating a humoral response after 100 days. Conclusions Two doses of CoronaVac induces antibody titers against the SARS-CoV-2 ancestral strain which are lower in magnitude than those induced by the BNT162b2 vaccine. However, the response induced by CoronaVac can be greatly potentiated with a heterologous booster scheme with BNT162b2 or ChAdOx1 vaccines. Furthermore, the heterologous and homologous booster regimes induce a durable antibody response which does not show signs of decay 3 months after the booster dose.

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Challenges in surveillance of all cancer cases: The Chilean National Cancer Registry

2024 , Carla Taramasco , Carla Rimassa , ACEVEDO ROMO, JOHANNA PATRICIA

Cancer causes millions of deaths worldwide, making its registration essential. There are clinical, hospital, and population-based registries in place. The latter is the gold standard for information on cancer incidence and survival in a defined region. Chile has five population-based registries located in specific areas of the country. The Chilean National Cancer Registry emerged with the challenge of creating a tool encompassing all three types of registries to identify the number of cancer cases by type. Its design involved a series of actions to achieve consensus among various actors regarding information, validation, and events to be registered. Four stages were identified in the care and registration process: suspected diagnosis, morphological confirmation (biopsy), clinical resolution (oncology committee, including treatment recommendations), treatment, and oncological follow-up. The platform's development (from 2018 to 2021) involved gathering information and agreements on the requirements for co-designing the registry, including a successful pilot program with over 20 public and private healthcare facilities that recorded nearly 7500 cancer cases. The deployment and use of the National Cancer Registry at a national level depends on the healthcare authority. It is an information system that continuously and systematically collects, stores, processes, and analyzes data on all cancer cases and types occurring in the country. This work presents the design and development of the tool, the challenges addressed, as well as its strengths and weaknesses.

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Neutralizing antibodies induced by homologous and heterologous boosters in CoronaVac vaccines in Chile

2023 , ACEVEDO ROMO, JOHANNA PATRICIA , Mónica L. Acevedo , Aracelly Gaete-Argel , ARAOS BRALIC, RAFAEL IGNACIO , Cecilia Gonzalez , Daniela Espinoza , Pablo Pizarro , RIVAS VERA, SOLANGE VERÓNICA , Stephan Jarpa , Ricardo Soto-Rifo , Alejandro Jara , Fernando Valiente-Echeverría

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High Burden of Intestinal Colonization With Antimicrobial-Resistant Bacteria in Chile: An Antibiotic Resistance in Communities and Hospitals (ARCH) Study

2023 , ARAOS BRALIC, RAFAEL IGNACIO , Rachel M Smith , Ashley Styczynski , Felipe Sánchez , Lea Maureira , ACEVEDO ROMO, JOHANNA PATRICIA , Catalina Paredes , Maite González , RIVAS JIMENEZ, LINA MARIA , Maria Spencer-Sandino , Anne Peters , Ayesha Khan , Dino Sepulveda , Loreto Rojas Wettig , María Luisa Rioseco , Pedro Usedo , Pamela Rojas Soto , Laura Andrea Huidobro , Catterina Ferreccio , Benjamin J Park , Eduardo Undurraga , Erika M C D’Agata , Alejandro Jara , MUNITA SEPULVEDA, JOSE MANUEL

Abstract Background Antimicrobial resistance is a global threat, heavily impacting low- and middle-income countries. This study estimated antimicrobial-resistant gram-negative bacteria (GNB) fecal colonization prevalence in hospitalized and community-dwelling adults in Chile before the coronavirus disease 2019 pandemic. Methods From December 2018 to May 2019, we enrolled hospitalized adults in 4 public hospitals and community dwellers from central Chile, who provided fecal specimens and epidemiological information. Samples were plated onto MacConkey agar with ciprofloxacin or ceftazidime added. All recovered morphotypes were identified and characterized according to the following phenotypes: fluoroquinolone-resistant (FQR), extended-spectrum cephalosporin-resistant (ESCR), carbapenem-resistant (CR), or multidrug-resistant (MDR; as per Centers for Disease Control and Prevention criteria) GNB. Categories were not mutually exclusive. Results A total of 775 hospitalized adults and 357 community dwellers were enrolled. Among hospitalized subjects, the prevalence of colonization with FQR, ESCR, CR, or MDR-GNB was 46.4% (95% confidence interval [CI], 42.9–50.0), 41.2% (95% CI, 37.7–44.6), 14.5% (95% CI, 12.0–16.9), and 26.3% (95% CI, 23.2–29.4). In the community, the prevalence of FQR, ESCR, CR, and MDR-GNB colonization was 39.5% (95% CI, 34.4–44.6), 28.9% (95% CI, 24.2–33.6), 5.6% (95% CI, 3.2–8.0), and 4.8% (95% CI, 2.6–7.0), respectively. Conclusions A high burden of antimicrobial-resistant GNB colonization was observed in this sample of hospitalized and community-dwelling adults, suggesting that the community is a relevant source of antibiotic resistance. Efforts are needed to understand the relatedness between resistant strains circulating in the community and hospitals.

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Differential Effects of a Telemonitoring Platform in the Development of Chemotherapy-Associated Toxicity: A Randomized Trial Protocol

2024 , Felipe Martínez , Carla Taramasco , Manuel Espinoza , ACEVEDO ROMO, JOHANNA PATRICIA , Carolina Goic , Bruno Nervi

Chemotherapy requires careful monitoring, but traditional follow-up approaches face significant challenges that were highlighted by the COVID-19 pandemic. Hence, exploration into telemonitoring as an alternative emerged. The objective is to assess the impact of a telemonitoring platform that provides clinical data to physicians overseeing solid tumor patients, aiming to enhance the care experience. The methodology outlines a parallel-group randomized clinical trial involving recently diagnosed patients with solid carcinomas preparing for curative intent chemotherapy. Eligible adult patients diagnosed with specific carcinoma types and proficient in Spanish, possessing smartphones, will be invited to participate. They will be randomized using concealed allocation sequences into two groups: one utilizing a specialized smartphone application called Contigo for monitoring chemotherapy toxicity symptoms and accessing educational content, while the other receives standard care. Primary outcome assessment involves patient experience during chemotherapy using a standardized questionnaire. Secondary outcomes include evaluating severe chemotherapy-associated toxicity, assessing quality of life, and determining user satisfaction with the application. The research will adhere to intention-to-treat principles. This study has been registered at ClinicalTrials.gov (NCT06077123).

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Effects on Quality of Life of a Telemonitoring Platform amongst Patients with Cancer (EQUALITE): A Randomized Trial Protocol

2024 , Felipe Martínez , Carla Taramasco , Manuel Espinoza , ACEVEDO ROMO, JOHANNA PATRICIA , Carolina Goic , Bruno Nervi

Cancer, a pervasive global health challenge, necessitates chemotherapy or radiotherapy treatments for many prevalent forms. However, traditional follow-up approaches encounter limitations, exacerbated by the recent COVID-19 pandemic. Consequently, telemonitoring has emerged as a promising solution, although its clinical implementation lacks comprehensive evidence. This report depicts the methodology of a randomized trial which aims to investigate whether leveraging a smartphone app called Contigo for disease monitoring enhances self-reported quality of life among patients with various solid cancers compared to standard care. Secondary objectives encompass evaluating the app’s impact on depressive symptoms and assessing adherence to in-person appointments. Randomization will be performed independently using an allocation sequence that will be kept concealed from clinical investigators. Contigo offers two primary functions: monitoring cancer patients’ progress and providing educational content to assist patients in managing common clinical situations related to their disease. The study will assess outcomes such as quality of life changes and depressive symptom development using validated scales, and adherence to in-person appointments. Specific scales include the EuroQol Group’s EQ-5D questionnaire and the Patient Health Questionnaire (PHQ-9). We hypothesize that the use of Contigo will assist and empower patients receiving cancer treatment, which will translate to better quality of life scores and a reduced incidence of depressive symptoms. All analyses will be undertaken with the intention-to-treat principle by a statistician unaware of treatment allocation. This trial is registered in ClinicalTrials under the registration number NCT06086990.

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Effectiveness of an inactivated SARS-CoV-2 vaccine in children and adolescents: a large-scale observational study

2023 , Alejandro Jara , Eduardo A. Undurraga , Juan Carlos Flores , José R. Zubizarreta , Cecilia González , Alejandra Pizarro , Duniel Ortuño-Borroto , ACEVEDO ROMO, JOHANNA PATRICIA , Katherinne Leo , Fabio Paredes , Tomás Bralic , Verónica Vergara , Francisco Leon , Ignacio Parot , Paulina Leighton , Pamela Suárez , Juan Carlos Rios , Heriberto García-Escorza , ARAOS BRALIC, RAFAEL IGNACIO