Evaluating targeted COVID-19 vaccination strategies with agent-based modeling.

We evaluate approaches to vaccine distribution using an agent-based model of human activity and COVID-19 transmission calibrated to detailed trends in cases, hospitalizations, deaths, seroprevalence, and vaccine breakthrough infections in Florida, USA. We compare the incremental effectiveness for four different distribution strategies at four different levels of vaccine supply, starting in late 2020 through early 2022. Our analysis indicates that the best strategy to reduce severe outcomes would be to actively target high disease-risk individuals. This was true in every scenario, although the advantage was greatest for the intermediate vaccine availability assumptions and relatively modest compared to a simple mass vaccination approach under high vaccine availability. Ring vaccination, while generally the most effective strategy for reducing infections, ultimately proved least effective at preventing deaths. We also consider using age group as a practical surrogate measure for actual disease-risk targeting; this approach also outperforms both simple mass distribution and ring vaccination. We find that quantitative effectiveness of a strategy depends on whether effectiveness is assessed after the alpha, delta, or omicron wave. However, these differences in absolute benefit for the strategies do not change the ranking of their performance at preventing severe outcomes across vaccine availability assumptions.

Concordance between nice classification and histopathology in colonic polyps: a tertiary center experience.

Background: Narrow-Band imaging International Colorectal Endoscopic (NICE) could reduce histopathology study requirements in colorectal polyp evaluation. Local and regional studies are required to validate its utility. Objectives: To evaluate concordance between NICE classification and histopathology. Design: Prospective analytic study performed in the Hospital Universitario San Ignacio, Bogotá (Colombia) between 2021 and 2022. Methods: Concordance between NICE I, II and III classification and histopathology [Hyperplastic Polyp (HP), adenoma and deep submucosal invasive cancer (DSIC)] was evaluated using weighted kappa. Diagnostic performance was evaluated for NICE I-II versus NICE III for DSIC versus adenoma/HP. A subgroup analysis was performed for polyps ⩾10 mm and those located in the rectum, sigmoid, and left colon. Results: A total of 238 polyps from 135 patients were evaluated. Median age 67 years (IQR 58.5-74.5), 54.4% males. 23 (17.1%) had ⩾3 polyps. Of polyps, 52.1% were located on rectum, sigmoid and left colon. A total of 182 (76.5%) were <10 mm. NICE and histopathology evidenced a fair-moderate concordance (quadratic weighted kappa 0.36, linear weighted kappa 0.43). NICE classification (NICE I-II versus III) compared to histopathology (DSIC versus adenoma/HP) evidenced a sensitivity of 90.9% and specificity of 99.1%. For DSIC diagnosis specificity was ⩾95% on polyps ⩾10 mm and those left sided located. Conclusion: NICE and histopathology concordance is suboptimal. However, NICE III for DSIC diagnosis evidence good specificity. Therefore, NICE III polyps require a prompt histopathological evaluation and follow-up. Good operative characteristics stand in polyps ⩾10 mm and left sided located. NBI formal training is recommended in gastroenterology units in Latin America.

Concordance between colonoscopy polyp evaluation with NBI optical technology and histopathology evaluation Most colorectal cancer are developed from polyps. A proper polyp evaluation is required to orientate which polyp could be a potential neoplasia. However, a definitive diagnosis is made according to histopathology evaluation. On the other hand, Narrow-Band imaging International Colorectal Endoscopic (NICE) classification based on colonoscopy could predict neoplastic polyps and drive therapeutic decisions. Our tertiary center study in Colombia evidence that NICE classification predicts adequately neoplastic polyps but is suboptimal to categorize low risk polyps. Therefore, histopathology polyp evaluation should be still recommended and NBI formal training is recommended in gastroenterology units in Latin -America.