1154. Impact of Vaccination Protocol Implementation and Splenectomized Patient Management in a Specialized Clinic on Incidence of Encapsulated Bacterial Infections: a Retrospective Cohort Study in Quebec, Canada
Bibliographic record
Abstract
Abstract Background Splenectomy weakens immunity against encapsulated bacteria and is associated with increased overwhelming post-splenectomy infection rates. The impact of recommended vaccines for these bacterial infections has not been studied in Quebec. This study aims to i) assess changes in the incidence of encapsulated bacterial infections in patients who underwent splenectomy at Centre Hospitalier Universitaire de Sherbrooke (CHUS) from 1990 to 2019; ii) Investigate any changes in vaccine coverage following the implementation of: 1) a peri-splenectomy vaccination protocol in 2005 and 2) the creation of a clinic dedicated to splenectomized patients in 2015. Methods This retrospective cohort study selected splenectomy cases performed between 1990 and 2019 at CHUS. Bacterial infections (S. pneumoniae, H. influenzae, and N. meningitidis) were identified from electronic files of microbiology laboratories. Temporal trends were assessed over three periods according to the years in which pneumococcal polysaccharide and conjugate vaccines were recommended (1990–1998; 1999–2012; 2013–2019). The primary outcome was occurrence of vaccine-preventable infection within 5 years of splenectomy. Results The study included 544 splenectomized patients. The proportion of patients aged ≥65 years significantly increased over time [1990–1998: 30%; 1999–2012: 39%; 2013–2019: 44%; p=0.03]. S. pneumoniae [1990–1998: 6%; 1999–2012: 3%; 2013–2019: 0%; p=0.007] and H. influenzae infections significantly decreased [1990–1998: 11%; 1999–2012: 6%; 2013–2019: 0%; p=0.007]. Vaccination protocol implementation was associated with increase in the number of adequately vaccinated patients (Hib and PPV) in the 6 months after splenectomy [pre-protocol: 21%; post-protocol: 66%; p< 0.0001]. A significant difference between vaccination coverage (Hib, VPP, and VPC) in the 6 months after the splenectomy of patients seen in the immunization clinic (49%) and those not referred (8%) was observed (p< 0.0001). Conclusion Marked decrease in post-splenectomy infection rates was observed in our population over 30 years, despite aging. Vaccination protocol implementation and splenectomized patient management in a specialized clinic can improve vaccination coverage. Disclosures Alex Carignan, MD, MSc, GSK: Advisor/Consultant|GSK: Grant/Research Support|GSK: Honoraria|Moderna: Advisor/Consultant|Moderna: Honoraria|Orimed Pharma: Advisor/Consultant|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Pfizer: Honoraria
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".