Background: Cancer cell line-derived feeder cells enhance natural killer (NK) cell expansion; however, concerns regarding viable residual feeder cells in the final product limit their use. Evidence supporting the safety of NK-sensitive K562-based feeders, even when irradiated, is scarce. We optimized an NK cell expansion protocol using genetically engineered K562-mbIL-18/-21 (GE-K562) feeder cells and clinical-grade media and confirmed the absence of residual feeder cells. Methods: NK cell expansion efficiency was compared between feeder-free and feederbased systems using CTS NK-Xpander Medium. To achieve optimal NK expansion, various peripheral blood mononuclear cell (PBMC)-to-feeder ratios and re-stimulation frequencies were tested over 21 days. Flow cytometry and BCR::ABL1 quantitative reverse transcription PCR (RT-qPCR) were used to confirm the absence of feeder cells in the final NK cell product. Results: Feeder-based systems showed superior NK cell fold expansion compared with that of feeder-free systems. Among feeder-based conditions, NK cells expanded 5,224-fold at a 2:1 PBMC-to-feeder ratio after 3 weeks, relative to 1,450-fold at a 6:1 ratio (P < 0.05).Re-stimulation on days 7 and 14 further increased expansion up to 261,457-fold. Irradiated feeder cells showed no proliferation and were eliminated within 3–6 days. On day 21, flow cytometry and BCR::ABL1 RT-qPCR results confirmed the absence of residual feeder cells. Conclusions Our optimized NK cell expansion protocol using irradiated GE-K562 feeder cells and clinical-grade media offers a safe and scalable approach to generating large numbers of NK cells, supporting its potential use in clinical immunotherapy applications.

Purpose: Forming a patient safety culture is the first step in addressing patient safety issues. This study therefore examines the patient safety culture among healthcare professionals in South Korea. It also identifies the factors influencing patient safety culture and related activities. Methods: Among the survey studies conducted in South Korea, we reviewed those that measured patient safety culture using the Korean version of the Hospital Survey on Patient Safety Culture 1.0. We identified the level of patient safety culture, the relationship between patient safety culture and patient safety activities, and the factors affecting patient safety culture. Results: A total of 640 studies were identified through searches of seven domestic and international databases, with 58 included in the analysis. Studies targeting nurses accounted for 96.6%. The general characteristics of patient safety culture included length of service, age, working hours, department of work, hospital size, conflict occurrence, unreported incidents, and subjective safety management evaluations. A statistically significant correlation between patient safety culture and patient safety activities was confirmed in 84.5% of studies. Patient safety culture was the most frequently reported factor influencing patient safety activities. Conclusion Strategies to enhance patient safety culture can promote patient safety activities in South Korean healthcare institutions. Considering organizational and organizational members characteristics when devising these strategies can enhance their effectiveness.

Purpose: Forming a patient safety culture is the first step in addressing patient safety issues. This study therefore examines the patient safety culture among healthcare professionals in South Korea. It also identifies the factors influencing patient safety culture and related activities. Methods: Among the survey studies conducted in South Korea, we reviewed those that measured patient safety culture using the Korean version of the Hospital Survey on Patient Safety Culture 1.0. We identified the level of patient safety culture, the relationship between patient safety culture and patient safety activities, and the factors affecting patient safety culture. Results: A total of 640 studies were identified through searches of seven domestic and international databases, with 58 included in the analysis. Studies targeting nurses accounted for 96.6%. The general characteristics of patient safety culture included length of service, age, working hours, department of work, hospital size, conflict occurrence, unreported incidents, and subjective safety management evaluations. A statistically significant correlation between patient safety culture and patient safety activities was confirmed in 84.5% of studies. Patient safety culture was the most frequently reported factor influencing patient safety activities. Conclusion Strategies to enhance patient safety culture can promote patient safety activities in South Korean healthcare institutions. Considering organizational and organizational members characteristics when devising these strategies can enhance their effectiveness.

Purpose: Forming a patient safety culture is the first step in addressing patient safety issues. This study therefore examines the patient safety culture among healthcare professionals in South Korea. It also identifies the factors influencing patient safety culture and related activities. Methods: Among the survey studies conducted in South Korea, we reviewed those that measured patient safety culture using the Korean version of the Hospital Survey on Patient Safety Culture 1.0. We identified the level of patient safety culture, the relationship between patient safety culture and patient safety activities, and the factors affecting patient safety culture. Results: A total of 640 studies were identified through searches of seven domestic and international databases, with 58 included in the analysis. Studies targeting nurses accounted for 96.6%. The general characteristics of patient safety culture included length of service, age, working hours, department of work, hospital size, conflict occurrence, unreported incidents, and subjective safety management evaluations. A statistically significant correlation between patient safety culture and patient safety activities was confirmed in 84.5% of studies. Patient safety culture was the most frequently reported factor influencing patient safety activities. Conclusion Strategies to enhance patient safety culture can promote patient safety activities in South Korean healthcare institutions. Considering organizational and organizational members characteristics when devising these strategies can enhance their effectiveness.

Objectives: The aim of this study was to disseminate information about the safety of bivalent coronavirus disease 2019 (COVID-19) mRNA booster vaccines administered to adults in the Republic of Korea. Methods: Two databases were used to assess the safety of COVID-19 booster doses of Pfizer BA.1, Pfizer BA.4/5, Moderna BA.1, and Moderna BA.4/5 vaccines for adults aged 18 years and older.Adverse events (AEs) were analyzed using data reported to the web-based COVID-19 vaccination management system (CVMS) and a self-reported text-message survey. Results: Between October 11, 2022 and March 30, 2023, the CVMS received reports of 2,369 (93.7%) non-serious AEs from vaccinated adults, along with 158 (6.3%) serious AEs, which included 5 cases of anaphylaxis and 33 deaths. From October 11, 2022 to January 27, 2023, 40,022 people aged 18 and older responded to a survey conducted via text message. The booster doses were associated with fewer local and systemic AEs compared to the original vaccines. After receiving the bivalent vaccine, the most commonly reported AEs were pain at the injection site, headache, fatigue, and myalgia. Conclusion Overall, bivalent vaccines exhibited fewer AEs compared to the original vaccines. The majority of AEs were non-serious, and serious AEs were rare among adults aged 18 years and older following vaccination with the Pfizer and Moderna bivalent vaccines.

Objectives: This study analyzed the safety of coronavirus disease 2019 (COVID-19) bivalent and monovalent booster vaccines, including the frequency of adverse events (AEs) such as myocarditis and pericarditis, in adolescents aged 12 to 17 years in the Republic of Korea. Weaimed to share the safety profile of the COVID-19 bivalent vaccine booster doses. Methods: We analyzed the frequencies of AEs reported to the COVID-19 vaccination management system (CVMS) or self-reported through the text message survey (TMS). Diagnostic eligibility and causality with vaccines were compared using odds ratios (ORs) by vaccine type, and incidencerates per 100,000 person-days were calculated for confirmed cases of myocarditis andpericarditis following monovalent and bivalent booster doses. Results: In the CVMS, the AE reporting rate (per 100,000 doses) was lower after the bivalent booster (66.5) than after the monovalent booster (264.6). Among the AEs reported for both monovalent and bivalent vaccines 98.3% were non-serious and 1.7% were serious. According to the TMS, both local and systemic AEs were reported less frequently after the bivalent vaccination than after the monovalent vaccination in adolescents aged 12 to 17 years (p < 0.001).The incidence rates per 100,000 person-days for confirmed myocarditis/pericarditis following monovalent and bivalent booster doses were 0.03 and 0.05, respectively; this difference was not statistically significant (OR, 1.797; 95% confidence interval, 0.210–15.386). Conclusion AEs in 12- to 17-year-olds following the bivalent booster were less frequent than those following the monovalent booster in the Republic of Korea, and no major safety issueswere identified. However, the reporting rates for AEs were low.

Objectives: The aim of this study was to disseminate information about the safety of bivalent coronavirus disease 2019 (COVID-19) mRNA booster vaccines administered to adults in the Republic of Korea. Methods: Two databases were used to assess the safety of COVID-19 booster doses of Pfizer BA.1, Pfizer BA.4/5, Moderna BA.1, and Moderna BA.4/5 vaccines for adults aged 18 years and older.Adverse events (AEs) were analyzed using data reported to the web-based COVID-19 vaccination management system (CVMS) and a self-reported text-message survey. Results: Between October 11, 2022 and March 30, 2023, the CVMS received reports of 2,369 (93.7%) non-serious AEs from vaccinated adults, along with 158 (6.3%) serious AEs, which included 5 cases of anaphylaxis and 33 deaths. From October 11, 2022 to January 27, 2023, 40,022 people aged 18 and older responded to a survey conducted via text message. The booster doses were associated with fewer local and systemic AEs compared to the original vaccines. After receiving the bivalent vaccine, the most commonly reported AEs were pain at the injection site, headache, fatigue, and myalgia. Conclusion Overall, bivalent vaccines exhibited fewer AEs compared to the original vaccines. The majority of AEs were non-serious, and serious AEs were rare among adults aged 18 years and older following vaccination with the Pfizer and Moderna bivalent vaccines.