Song Mi Moon

Jeong EJ, et al. J Korean Med Sci. 2027 Jan;42:e23. https://doi.org/10.3346/jkms.2027.42.e23

Kim SA, et al. J Korean Med Sci. 2026 Dec;41:e330. https://doi.org/10.3346/jkms.2026.41.e330

Kwon H, et al. Infect Chemother. 2026 ;58:e45. https://doi.org/10.3947/ic.2026.0044

Lim SM, et al. J Korean Med Sci. 2026 Oct;41:e253. https://doi.org/10.3346/jkms.2026.41.e253

[This corrects the article DOI: 10.1017/ash.2024.75.].

Throughout the 2019 coronavirus disease pandemic, various vaccine regimens were implemented. Real-world data comparing their effectiveness during the BA.1/BA.2 Omicron wave remain limited. We prospectively enrolled healthcare workers who had completed two doses of mRNA or ChAdOx1 (A) vaccine and received an mRNA vaccine booster (BNT162b2 (P) or mRNA-1273 (M)). Neutralizing antibody levels were measured 6 months after the primary vaccinations and 1 month post-booster vaccination using a surrogate virus neutralization assay. Breakthrough infections were identified through institutional surveillance and the national reporting system. Among 318 participants (P-P-P: 71; A-A-P: 205; A-P-P: 19; M-M-M: 23), pre-booster neutralizing activity was lowest in the ChAdOx1-primed groups. One month post-booster vaccination, the neutralizing activity exceeded 97% across all regimens. The cumulative incidence of breakthrough infection varied significantly from 43.7% (P-P-P) to 84.2% (A-P-P). In adjusted Cox models, A-P-P showed the highest infection risk (HR 2.99, 95% CI 1.65–5.42). In summary, mRNA boosters restored neutralizing activity, but during the early BA.1/BA.2 Omicron wave they were less effective in preventing infections regardless of disease severity. Therefore, antibody titers alone are insufficient for evaluating protection, underscoring the need for continuous monitoring to support timely policy decisions during epidemic surges.

Although large language models (LLMs) have demonstrated impressive reasoning capabilities across general domains, their effectiveness in real-world clinical practice remains limited. This is likely due to their insufficient exposure to real-world clinical data during training, as such data is typically not included due to privacy concerns. To address this, we propose enhancing the clinical reasoning capabilities of LLMs by leveraging real-world clinical data. We constructed reasoning-intensive questions from a nationwide sepsis registry and fine-tuned Phi-4 on these questions using reinforcement learning, resulting in C-Reason. C-Reason exhibited strong clinical reasoning capabilities on the in-domain test set, as evidenced by both quantitative metrics and expert evaluations. Furthermore, its enhanced reasoning capabilities generalized to a sepsis dataset involving different tasks and patient cohorts, an open-ended consultations on antibiotics use task, and other diseases. Future research should focus on training LLMs with large-scale, multi-disease clinical datasets to develop more powerful, general-purpose clinical reasoning models.

Despite rapid deaths resulting from Acinetobacter baumannii bacteremia, the clinical impact of the microbiological characteristics of A baumannii strains on early mortality (EM) is unclear. We aimed to identify the microbiological characteristics of A baumannii strains associated with EM. Clinical information and isolates from patients with A baumannii bacteremia from January 2015 to December 2021 were collected. EM was defined as death within 3 days of the initial positive blood culture, whereas late mortality meant death within 5–30 days. The microbiological characteristics of A baumannii were analyzed using multilocus sequence typing, polymerase chain reactions, and a Galleria mellonella in vivo infection model. Among 130 patients, 69 (53.1%) died within 30 days and EM occurred in 38 (55.1% of 30-day deaths). Sequence type 191 (ST191) strain was more prevalent in patients with EM than in 30-day survivors (31.6% vs 6.6%). Regarding virulence genes, bfmS was more frequent (92.1% vs 47.5%), whereas bauA was less frequent (13.2% vs 52.5%) in patients with EM than in 30-day survivors. Higher clinical severity, pneumonia, and ST191 infection were identified as independent risk factors for EM. In the G mellonella infection model, ST191, bfmS+, and bauA– isolates showed higher virulence than non-ST191, bfmS–, and bauA+ isolates, respectively. ST191 and bfmS were more frequently found in the EM group. ST191 infection was also an independent risk factor for EM and highly virulent in the in vivo model. Tailored infection control measures based on these characteristics are necessary for A baumannii bacteremia management.

Objective: This study aimed to assess the actual burden of antibiotic use among end-of-life (EOL) patients in South Korea and to compare trends between cancer and non-cancer decedents. Design: Population-based mortality follow-back study. Setting: Data from the Korean National Health Insurance Database, covering the period from January1, 2006, to December 31, 2018, provided for research by the National Health Insurance Service (NHIS), were used. Participants: All decedents from 2006 to 2018 were included and categorized as cancer decedents or non-cancer decedents. Methods: Annual antibiotic consumption rates and prescription rates were calculated, and Poisson regression was used to estimate their trends. Results: Overall antibiotic consumption rates decreased slightly among decedents in their final month with a less pronounced annual decrease rate among cancer decedents compared to non-cancer decedents (0.4% vs 2.3% per year, P <.001). Over the study period, although narrow spectrum antibiotics were used less, utilization and prescription of broad-spectrum antibiotics steadily increased, and prescription rates were higher in cancer decedents compared to non-cancer controls. Specifically, carbapenem prescription rates increased from 5.6% to 18.5%, (RR 1.087, 95% CI 1.085–1.088, P <.001) in cancer decedents and from 2.9% to 13.2% (RR 1.115, 95% CI 1.113–1.116, P <.001) in non-cancer decedents. Conclusions: Our findings show that patients at the EOL, especially those with cancer, are increasingly and highly exposed to broad-spectrum antibiotics. Measures of antibiotic stewardship are required among this population.

Park SY, et al. Infect Chemother. 2024 Aug;56:e35. https://doi.org/10.3947/ic.2024.0038