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

BACKGROUND: Mass vaccination campaigns to prevent coronavirus disease 2019 (Covid-19) are occurring in many countries; estimates of vaccine effectiveness are urgently needed to support decision making. A countrywide mass vaccination campaign with the use of an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine (CoronaVac) was conducted in Chile starting on February 2, 2021. METHODS: We used a prospective national cohort, including participants 16 years of age or older who were affiliated with the public national health care system, to assess the effectiveness of the inactivated SARS-CoV-2 vaccine with regard to preventing Covid-19 and related hospitalization, admission to the intensive care unit (ICU), and death. We estimated hazard ratios using the extension of the Cox proportional-hazards model, accounting for time-varying vaccination status. We estimated the change in the hazard ratio associated with partial immunization (≥14 days after receipt of the first dose and before receipt of the second dose) and full immunization (≥14 days after receipt of the second dose). Vaccine effectiveness was estimated with adjustment for individual demographic and clinical characteristics. RESULTS: The study was conducted from February 2 through May 1, 2021, and the cohort included approximately 10.2 million persons. Among persons who were fully immunized, the adjusted vaccine effectiveness was 65.9% (95% confidence interval [CI], 65.2 to 66.6) for the prevention of Covid-19 and 87.5% (95% CI, 86.7 to 88.2) for the prevention of hospitalization, 90.3% (95% CI, 89.1 to 91.4) for the prevention of ICU admission, and 86.3% (95% CI, 84.5 to 87.9) for the prevention of Covid-19-related death. CONCLUSIONS: Our results suggest that the inactivated SARS-CoV-2 vaccine effectively prevented Covid-19, including severe disease and death, a finding that is consistent with results of phase 2 trials of the vaccine. (Funded by Agencia Nacional de Investigación y Desarrollo and others.).

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

Background: Policymakers urgently need evidence to adequately balance the costs and benefits of mass vaccination against COVID-19 across all age groups, including children and adolescents. In this study, we aim to assess the effectiveness of CoronaVac's primary series among children and adolescents in Chile. Methods: We used a large prospective national cohort of about two million children and adolescents 6-16 years to estimate the effectiveness of an inactivated SARS-CoV-2 vaccine (CoronaVac) in preventing laboratory-confirmed symptomatic SARS-CoV-2 infection (COVID-19), hospitalisation, and admission to an intensive care unit (ICU) associated with COVID-19. We compared the risk of individuals treated with a complete primary immunization schedule (two doses, 28 days apart) with the risk of unvaccinated individuals during the follow-up period. The study was conducted in Chile from June 27, 2021, to January 12, 2022, when the SARS-CoV-2 Delta variant was predominant but other variants of concern were co-circulating, including Omicron. We used inverse probability-weighted survival regression models to estimate hazard ratios of complete immunization over the unvaccinated status, accounting for time-varying vaccination exposure and adjusting for relevant demographic, socioeconomic, and clinical confounders. Findings: The estimated adjusted vaccine effectiveness for the inactivated SARS-CoV-2 vaccine in children aged 6-16 years was 74.5% (95% CI, 73.8-75.2), 91.0% (95% CI, 87.8-93.4), 93.8% (95% CI, 87.8-93.4) for the prevention of COVID-19, hospitalisation, and ICU admission, respectively. For the subgroup of children 6-11 years, the vaccine effectiveness was 75.8% (95% CI, 74.7-76.8) for the prevention of COVID-19 and 77.9% (95% CI, 61.5-87.3) for the prevention of hospitalisation. Interpretation: Our results suggest that a complete primary immunization schedule with the inactivated SARS-CoV-2 vaccine provides effective protection against severe COVID-19 disease for children 6-16 years. Funding: Agencia Nacional de Investigación y Desarrollo (ANID) Millennium Science Initiative Program and Fondo de Financiamiento de Centros de Investigación en Áreas Prioritarias (FONDAP).

Effectiveness of homologous and heterologous booster doses for an inactivated SARS-CoV-2 vaccine: a large-scale prospective cohort study.

BACKGROUND: Several countries have authorised or begun using a booster vaccine dose against COVID-19. Policy makers urgently need evidence of the effectiveness of additional vaccine doses and its clinical spectrum for individuals with complete primary immunisation schedules, particularly in countries where the primary schedule used inactivated SARS-CoV-2 vaccines. METHODS: Using individual-level data, we evaluated a prospective, observational, national-level cohort of individuals (aged ≥16 years) affiliated with the Fondo Nacional de Salud insurance programme in Chile, to assess the effectiveness of CoronaVac (Sinovac Biotech), AZD1222 (Oxford-AstraZeneca), or BNT162b2 (Pfizer-BioNTech) vaccine boosters in individuals who had completed a primary immunisation schedule with CoronaVac, compared with unvaccinated individuals. Individuals administered vaccines from Feb 2, 2021, to the prespecified study end date of Nov 10, 2021, were evaluated; we excluded individuals with a probable or confirmed SARS-CoV-2 infection (RT-PCR or antigen test) on or before Feb 2, 2021, and individuals who had received at least one dose of any COVID-19 vaccine before Feb 2, 2021. We estimated the vaccine effectiveness of booster doses against laboratory-confirmed symptomatic COVID-19 (symptomatic COVID-19) cases and COVID-19 outcomes (hospitalisation, admission to the intensive care unit [ICU], and death We used inverse probability-weighted and stratified survival regression models to estimate hazard ratios, accounting for time-varying vaccination status and adjusting for relevant demographic, socioeconomic, and clinical confounders. We estimated the change in hazard from unvaccinated status to vaccinated status associated with the primary immunisation series and a booster vaccine. FINDINGS: 11 174 257 individuals were eligible for this study, among whom 4 127 546 completed a primary immunisation schedule (two doses) with CoronaVac and received a booster dose during the study period. 1 921 340 (46·5%) participants received an AZD1222 booster, 2 019 260 (48·9%) received a BNT162b2 booster, and 186 946 (4·5%) received a homologous booster with CoronaVac. We calculated an adjusted vaccine effectiveness (weighted stratified Cox model) in preventing symptomatic COVID-19 of 78·8% (95% CI 76·8-80·6) for a three-dose schedule with CoronaVac, 96·5% (96·2-96·7) for a BNT162b2 booster, and 93·2% (92·9-93·6) for an AZD1222 booster. The adjusted vaccine effectiveness against COVID-19-related hospitalisation, ICU admission, and death was 86·3% (83·7-88·5), 92·2% (88·7-94·6), and 86·7% (80·5-91·0) for a homologous CoronaVac booster, 96·1% (95·3-96·9), 96·2% (94·6-97·3), and 96·8% (93·9-98·3) for a BNT162b2 booster, and 97·7% (97·3-98·0), 98·9% (98·5-99·2), and 98·1% (97·3-98·6) for an AZD1222 booster. INTERPRETATION: Our results suggest that a homologous or heterologous booster dose for individuals with a complete primary vaccination schedule with CoronaVac provides a high level of protection against COVID-19, including severe disease and death. Heterologous boosters showed higher vaccine effectiveness than a homologous booster for all outcomes, providing additional support for a mix-and-match approach. FUNDING: Agencia Nacional de Investigación y Desarrollo through the Fondo Nacional de Desarrollo Científico y Tecnológico, Millennium Science Initiative Program, and Fondo de Financiamiento de Centros de Investigación en Áreas Prioritarias.

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

The 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.

Valor predictivo positivo de las punciones de mama realizadas bajo guía ecográfica en el Hospital Universitario Austral - Buenos Aires - Argentina / Positive Predicitive Value of Breast Biopsy performed under Ultrasound guidance at Austral University Hospital ­ Buenos Aires - Argentina

Objetivo: determinar la calidad y efectividad del trabajo realizado en el Centro Mamario del Hospital Universitario Austral, mediante la correlación entre las diferentes categorizaciones del BI-RADS, el resultado de la anatomía patológica y el cálculo del respectivo VPP. Correlacionar los resultados con los obtenidos a nivel internacional. Material y método: se realizó una revisión de todas las biopsias guiadas por ultrasonido, se seleccionaron aquellas pacientes estudiadas con algún método de diagnóstico por imágenes en el Centro Mamario del Hospital Universitario Austral y cuya categorización final de BI-RADS fuera de 4 o 5, entre junio de 2014 y mayo de 2017. Los resultados de la anatomía patológica fueron divididos en 3 categorías (benigno, maligno y alto riesgo) Resultados: de una total de 491 pacientes 223 correspondieron a la subcategoría 4a, 69 pacientes a la subcategoría 4b, 85 pacientes a la subcategoría 4c y 114 pacientes a la categoría 5. En las subcategorías 4a y 4b predominaron las lesiones benignas y en la subcategoría 4c y categoría 5 predominaron las lesiones malignas. Los VPP para cáncer de mama obtenidos fueron de 7%, 48%, 84% y 98% para las subcategorías 4a, 4b, 4c y categoría 5 respectivamente. Conclusiones: la investigación demostró que los resultados de los VPP, la calidad y efectividad del trabajo realizado en el Centro Mamario del Hospital Universitario Austral se encuentran dentro de los parámetros internacionales.

Objetive: to determine the quality and effectiveness of the work carried out in the Breast Center of the Austral University Hospital, through the correlation between the different categorizations of the BI-RADS, the result of the pathological anatomy and the calculation of the respective VPP. Correlate the results with those obtained internationally. Material and method: a review of al ultasound-guided biopsies was performed, those patients studied with some diagnostic imaging method were selected in the Breast Center of the Austral University Hospital and whose final categorization of BI-RADS was 4 or 5, between june 2014 and may 2017. The results of the pathological anatomy were divided into 3 categories (bening, malignant and high risk). Results: from a total of 491 patients, 223 corresponded to subcategory 4a, 69 patients to subcategory 4b, 85 patiens to subcategory 4c and 114 patients to category 5. In subcategories 4a and 4b benign lesions predominated and in subcategory 4c and category 5, malignant lesions predominated. The VPP for breast cáncer obtained were 7%, 48%, 84% and 98% for subcategories 4a, 4b, 4c y category 5 respectively. Conclusions: the investigation showed that the results of the PPV, the quality and effectiveness of the work carried out in the Breast Center of the Autral University Hospital are within the international parameters.

Presentación de Caso Clínico: Carcinoma de mama luego de mastectomía de reducción de riesgo en paciente con mutación BRCA1 / Case report: Breast carcinoma after risk reducing mastectomy in a BRCA+ patient

Las pacientes sanas portadoras de mutaciones patogénicas del gen BRCA1 tiene un riesgo muy elevado de desarrollar cáncer de mama y ovario, con cifras reportadas que ascienden a 84% y 59% respec- tivamente.¹ Esto motivó a implementar distintas medidas de segui- miento y de reducción de riesgo, como la mastectomía bilateral de reducción de riesgo (MRR) y la salpingo-ooforectomía de reducción de riesgo (SORR). Pero aún así, distintas experiencias publicadas re- fieren que en pacientes portadoras de mutacion BRCA1 sometidas a MRR, el riesgo subsiguiente de desarrollar un cáncer primario de mama puede llegar al 10%.2 Por otro lado, las técnicas de mastectomías en general han experi- mentado modificaciones en menos, conservando las estructuras te- gumentarias y el tejido adiposo que la recubre. Últimamente se ha expuesto que, con la guía de las imágenes, se puede resecar menos tejido aun, fundamentalmente en los contornos mamarios donde se observa tejido adiposo y nada (o muy escaso) tejido glandular.3 Esta recomendación hoy es empírica, ya que no hay evidencia de la segu- ridad oncológica de conservar estos tejidos