We aimed to analyze the characteristics of serious adverse events following immunizations (AEFIs) to identify potential safety information and prediction features. We screened the individual case safety reports (ICSRs) in adults who received mRNA-based COVID-19 vaccines using the Vaccine Adverse Event Reporting System until December 2021. We identified the demographic and clinical characteristics of ICSRs and performed signal detection. We developed prediction models for serious AEFIs and identified the prognostic features using logistic regression. Serious ICSRs and serious AEFIs were 51,498 and 271,444, respectively. Hypertension was the most common comorbidity (22%). Signal detection indicated that the reporting odds ratio of acute myocardial infarction (AMI) was more than 10 times. Those who had experienced myocardial infarction (MI) were 5.7 times more likely to suffer from MI as an AEFI (95% CI 5.28–6.71). Moreover, patients who had atrial fibrillation (AF), acute kidney injury (AKI), cardiovascular accident (CVA), or pulmonary embolism (PE) were 7.02 times, 39.09 times, 6.03 times, or 3.97 times more likely to suffer from each AEFI, respectively. Our study suggests that vaccine recipients who had experienced MI, AF, AKI, CVA, or PE could require further evaluation and careful monitoring to prevent those serious AEFIs.

Doxorubicin and cyclophosphamide (AC)-based chemotherapy has been a standard regimen for early-stage breast cancer (ESBC) with an intermediate risk (10–20%) of febrile neutropenia (FN). Secondary prophylaxis of granulocyte colony-stimulating factor (G-CSF) is considered in patients receiving AC-based chemotherapy; however, relevant studies are limited. Here, we retrospectively reviewed the electronic medical records of 320 patients who completed adjuvant AC-based chemotherapy from September 2016 to September 2020. Approximately 46.6% of the patients developed severe neutropenic events (SNE) during AC-based chemotherapy. Secondary prophylaxis of G-CSF reduced the risk of recurrent SNE (p < 0.01) and the relative dose intensity (RDI) < 85% (p = 0.03) in patients who had experienced SNE during AC-based chemotherapy. Age ≥ 65 years (p = 0.02) and alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 60 IU/L (p = 0.04) were significant risk factors for RDI < 85%. The incidences of FN, grade 4 neutropenia, unscheduled hospitalization, and interruption to the dosing regimen were reduced in patients administered secondary prophylaxis with G-CSF (before vs. after administration: FN, 19.4% vs. 4.6%; grade 4 neutropenia, 86.1% vs. 14.8%; unscheduled hospitalization, 75.9% vs. 11.1%; interruption to the dosing regimen, 18.5% vs. 8.3%). This study indicated the importance of active intervention of G-CSF use to prevent recurrent SNE and improve clinical outcomes in patients with breast cancer who receive AC-based chemotherapy.

In South Korea, because of manpower and budgetary limitations, antimicrobial stewardship programs have relied on preauthorization. This study analyzed the impact of a prospective audit and feedback (PAF) program targeting inpatients undergoing intermittent hemodialysis or continuous renal replacement therapy, which was implemented at two community-based university hospitals. During three years of PAF, 27,906 antimicrobial prescriptions were reviewed, with 622 (2.2%) interventions. The mean incidence density per 1000 patient days of multidrug-resistant organisms, except for carbapenem-resistant Acinetobacter baumannii, decreased in the study population, whereas it increased among inpatients. Multivariable Poisson regression analysis revealed that after PAF, the incidences of vancomycin-resistant Enterococcus and mortality decreased (incidence risk ratio, 95% confidence interval: 0.53, 0.31–0.93 and 0.70, 0.55–0.90, respectively). Notably, after PAF, incorrect antimicrobial dosing rates significantly decreased (tau −0.244; p = 0.02). However, the incidences of other multidrug-resistant organisms, Clostridioides difficile, length of stay, and readmission did not significantly change. This study shows that in patients undergoing intermittent hemodialysis or continuous renal replacement, targeted PAF can significantly reduce multidrug-resistant organism rates and all-cause hospital mortality, despite limited resources. Furthermore, it can improve antimicrobial dosage accuracy.