1.Establishing an Active Vaccine Safety Surveillance System Using Large Scale Databases in Korea: Lessons and Scalable Insights for Global Application
Jin Gu YOON ; Eliel NHAM ; Yu Jung CHOI ; Min Joo CHOI ; Won Suk CHOI ; Young Kyung YOON ; Yu Bin SEO ; Hakjun HYUN ; Jung Yeon HEO ; Jin-Soo LEE ; Chung-Jong KIM ; Ji Yun NOH ; Joon Young SONG ; Hee Jin CHEONG
Journal of Korean Medical Science 2026;41(1):e47-
Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.
2.Sentinel Safety Monitoring System for Adverse Events of Special Interest Associated With Non-NIP Vaccines in Korea
Hakjun HYUN ; Jung Yeon HEO ; Yu Jung CHOI ; Eliel NHAM ; Jin Gu YOON ; Ji Yun NOH ; Joon Young SONG ; Woo Joo KIM ; Won Suk CHOI ; Min Joo CHOI ; Yu Bin SEO ; Jacob LEE ; Hee Jin CHEONG
Journal of Korean Medical Science 2025;40(16):e152-
South Korea’s current vaccination policies leave a surveillance gap for non-National Immunization Program (NIP) vaccines. In this study, we proposed a sentinel surveillance approach for monitoring the safety of non-NIP vaccines. Vaccination data were collected retrospectively among patients hospitalized with pre-defined adverse events of special interest (AESI) by reviewing electronic medical records in five university hospitals. This approach incorporates expert assessment to determine the causal relationship. We confirmed that 16 patients had received non-NIP vaccines among 860 patients diagnosed with AESI.We concluded one case of preeclampsia was possibly related to tetanus-diphtheria-pertussis vaccination. We propose a multi-hospital-based, retrospective assessment system for predefined AESIs as an alternative to active vaccine safety monitoring method. These efforts are expected to enhance both the accuracy and timeliness of safety monitoring in South Korea.
3.Sentinel Safety Monitoring System for Adverse Events of Special Interest Associated With Non-NIP Vaccines in Korea
Hakjun HYUN ; Jung Yeon HEO ; Yu Jung CHOI ; Eliel NHAM ; Jin Gu YOON ; Ji Yun NOH ; Joon Young SONG ; Woo Joo KIM ; Won Suk CHOI ; Min Joo CHOI ; Yu Bin SEO ; Jacob LEE ; Hee Jin CHEONG
Journal of Korean Medical Science 2025;40(16):e152-
South Korea’s current vaccination policies leave a surveillance gap for non-National Immunization Program (NIP) vaccines. In this study, we proposed a sentinel surveillance approach for monitoring the safety of non-NIP vaccines. Vaccination data were collected retrospectively among patients hospitalized with pre-defined adverse events of special interest (AESI) by reviewing electronic medical records in five university hospitals. This approach incorporates expert assessment to determine the causal relationship. We confirmed that 16 patients had received non-NIP vaccines among 860 patients diagnosed with AESI.We concluded one case of preeclampsia was possibly related to tetanus-diphtheria-pertussis vaccination. We propose a multi-hospital-based, retrospective assessment system for predefined AESIs as an alternative to active vaccine safety monitoring method. These efforts are expected to enhance both the accuracy and timeliness of safety monitoring in South Korea.
4.Post‑transplant cyclophosphamide plus anti‑thymocyte globulin decreased serum IL‑6 levels when compared with post‑transplant cyclophosphamide alone after haploidentical hematopoietic stem cell transplantation
Jeong Suk KOH ; Myung‑Won LEE ; Thi Thuy Duong PHAM ; Bu Yeon HEO ; Suyoung CHOI ; Sang‑Woo LEE ; Wonhyoung SEO ; Sora KANG ; Seul Bi LEE ; Chul Hee KIM ; Hyewon RYU ; Hyuk Soo EUN ; Hyo‑Jin LEE ; Hwan‑Jung YUN ; Deog‑Yeon JO ; Ik‑Chan SONG
Blood Research 2025;60():5-
Background:
Post-transplantation cyclophosphamide (PTCy) and anti-thymocyte globulin (ATG) are common pro‑ phylactic strategies for graft-versus-host disease (GVHD) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Interleukin (IL)-6 is a surrogate marker for cytokine release syndrome (CRS) and acute GVHD.Method The clinical outcomes and complications of haplo-HSCT with PTCy plus ATG versus PTCy monotherapy were compared according to serum IL-6 levels at Chungnam National University Hospital (Daejeon, South Korea) from Jan‑ uary 2019 to February 2023.
Results:
Forty patients who underwent haplo-HSCT were analyzed. A significant difference in IL-6 levels was observed between the PTCy plus ATG and PTCy alone groups (7.47 ± 10.55 vs. 117.65 ± 127.67; p = 0.003). More patients in the PTCy plus ATG group had a CRS grade of 0 than in the PTCy alone group (p < 0.001). Serum IL-6 levels were associated with grades II–IV acute GVHD (r = 0.547, p < 0.001). The cumulative incidence (CI) of grades II–IV acute GVHD was significantly higher in the PTCy alone group (67.9% vs. 4.8%; p < 0.001). No significant difference in the CI for chronic GVHD was detected between the PTCy plus ATG and PTCy alone groups (72.1% vs. 82.0%; p = 0.730). The CI of 1-year non-relapse mortality was significantly higher in the PTCy alone group than in the PTCy plus ATG group (42.2% vs. 15.9%; p = 0.022). The 1-year overall survival (OS) was significantly better in the PTCy plus ATG group (75.9% vs. 35.3%; p = 0.011). The 1-year GVHD-free, relapse-free survival rate was 29.4% in the PTCy alone group and 54.0% in the PTCy plus ATG group (p = 0.038).
Conclusion
Serum IL-6 levels were higher in the PTCy alone group than in the PTCy plus ATG group. The addition of ATG before stem cell infusion affected IL-6 levels and reduced the incidences of CRS and grade II–IV acute GVHD in haplo-HSCT patients. This study suggests that PTCy plus ATG as GVHD prophylaxis in haplo-HSCT is beneficial in terms of clinical outcomes and complications of HSCT.
5.Post‑transplant cyclophosphamide plus anti‑thymocyte globulin decreased serum IL‑6 levels when compared with post‑transplant cyclophosphamide alone after haploidentical hematopoietic stem cell transplantation
Jeong Suk KOH ; Myung‑Won LEE ; Thi Thuy Duong PHAM ; Bu Yeon HEO ; Suyoung CHOI ; Sang‑Woo LEE ; Wonhyoung SEO ; Sora KANG ; Seul Bi LEE ; Chul Hee KIM ; Hyewon RYU ; Hyuk Soo EUN ; Hyo‑Jin LEE ; Hwan‑Jung YUN ; Deog‑Yeon JO ; Ik‑Chan SONG
Blood Research 2025;60():5-
Background:
Post-transplantation cyclophosphamide (PTCy) and anti-thymocyte globulin (ATG) are common pro‑ phylactic strategies for graft-versus-host disease (GVHD) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Interleukin (IL)-6 is a surrogate marker for cytokine release syndrome (CRS) and acute GVHD.Method The clinical outcomes and complications of haplo-HSCT with PTCy plus ATG versus PTCy monotherapy were compared according to serum IL-6 levels at Chungnam National University Hospital (Daejeon, South Korea) from Jan‑ uary 2019 to February 2023.
Results:
Forty patients who underwent haplo-HSCT were analyzed. A significant difference in IL-6 levels was observed between the PTCy plus ATG and PTCy alone groups (7.47 ± 10.55 vs. 117.65 ± 127.67; p = 0.003). More patients in the PTCy plus ATG group had a CRS grade of 0 than in the PTCy alone group (p < 0.001). Serum IL-6 levels were associated with grades II–IV acute GVHD (r = 0.547, p < 0.001). The cumulative incidence (CI) of grades II–IV acute GVHD was significantly higher in the PTCy alone group (67.9% vs. 4.8%; p < 0.001). No significant difference in the CI for chronic GVHD was detected between the PTCy plus ATG and PTCy alone groups (72.1% vs. 82.0%; p = 0.730). The CI of 1-year non-relapse mortality was significantly higher in the PTCy alone group than in the PTCy plus ATG group (42.2% vs. 15.9%; p = 0.022). The 1-year overall survival (OS) was significantly better in the PTCy plus ATG group (75.9% vs. 35.3%; p = 0.011). The 1-year GVHD-free, relapse-free survival rate was 29.4% in the PTCy alone group and 54.0% in the PTCy plus ATG group (p = 0.038).
Conclusion
Serum IL-6 levels were higher in the PTCy alone group than in the PTCy plus ATG group. The addition of ATG before stem cell infusion affected IL-6 levels and reduced the incidences of CRS and grade II–IV acute GVHD in haplo-HSCT patients. This study suggests that PTCy plus ATG as GVHD prophylaxis in haplo-HSCT is beneficial in terms of clinical outcomes and complications of HSCT.
6.Sentinel Safety Monitoring System for Adverse Events of Special Interest Associated With Non-NIP Vaccines in Korea
Hakjun HYUN ; Jung Yeon HEO ; Yu Jung CHOI ; Eliel NHAM ; Jin Gu YOON ; Ji Yun NOH ; Joon Young SONG ; Woo Joo KIM ; Won Suk CHOI ; Min Joo CHOI ; Yu Bin SEO ; Jacob LEE ; Hee Jin CHEONG
Journal of Korean Medical Science 2025;40(16):e152-
South Korea’s current vaccination policies leave a surveillance gap for non-National Immunization Program (NIP) vaccines. In this study, we proposed a sentinel surveillance approach for monitoring the safety of non-NIP vaccines. Vaccination data were collected retrospectively among patients hospitalized with pre-defined adverse events of special interest (AESI) by reviewing electronic medical records in five university hospitals. This approach incorporates expert assessment to determine the causal relationship. We confirmed that 16 patients had received non-NIP vaccines among 860 patients diagnosed with AESI.We concluded one case of preeclampsia was possibly related to tetanus-diphtheria-pertussis vaccination. We propose a multi-hospital-based, retrospective assessment system for predefined AESIs as an alternative to active vaccine safety monitoring method. These efforts are expected to enhance both the accuracy and timeliness of safety monitoring in South Korea.
7.Sentinel Safety Monitoring System for Adverse Events of Special Interest Associated With Non-NIP Vaccines in Korea
Hakjun HYUN ; Jung Yeon HEO ; Yu Jung CHOI ; Eliel NHAM ; Jin Gu YOON ; Ji Yun NOH ; Joon Young SONG ; Woo Joo KIM ; Won Suk CHOI ; Min Joo CHOI ; Yu Bin SEO ; Jacob LEE ; Hee Jin CHEONG
Journal of Korean Medical Science 2025;40(16):e152-
South Korea’s current vaccination policies leave a surveillance gap for non-National Immunization Program (NIP) vaccines. In this study, we proposed a sentinel surveillance approach for monitoring the safety of non-NIP vaccines. Vaccination data were collected retrospectively among patients hospitalized with pre-defined adverse events of special interest (AESI) by reviewing electronic medical records in five university hospitals. This approach incorporates expert assessment to determine the causal relationship. We confirmed that 16 patients had received non-NIP vaccines among 860 patients diagnosed with AESI.We concluded one case of preeclampsia was possibly related to tetanus-diphtheria-pertussis vaccination. We propose a multi-hospital-based, retrospective assessment system for predefined AESIs as an alternative to active vaccine safety monitoring method. These efforts are expected to enhance both the accuracy and timeliness of safety monitoring in South Korea.
8.Post‑transplant cyclophosphamide plus anti‑thymocyte globulin decreased serum IL‑6 levels when compared with post‑transplant cyclophosphamide alone after haploidentical hematopoietic stem cell transplantation
Jeong Suk KOH ; Myung‑Won LEE ; Thi Thuy Duong PHAM ; Bu Yeon HEO ; Suyoung CHOI ; Sang‑Woo LEE ; Wonhyoung SEO ; Sora KANG ; Seul Bi LEE ; Chul Hee KIM ; Hyewon RYU ; Hyuk Soo EUN ; Hyo‑Jin LEE ; Hwan‑Jung YUN ; Deog‑Yeon JO ; Ik‑Chan SONG
Blood Research 2025;60():5-
Background:
Post-transplantation cyclophosphamide (PTCy) and anti-thymocyte globulin (ATG) are common pro‑ phylactic strategies for graft-versus-host disease (GVHD) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Interleukin (IL)-6 is a surrogate marker for cytokine release syndrome (CRS) and acute GVHD.Method The clinical outcomes and complications of haplo-HSCT with PTCy plus ATG versus PTCy monotherapy were compared according to serum IL-6 levels at Chungnam National University Hospital (Daejeon, South Korea) from Jan‑ uary 2019 to February 2023.
Results:
Forty patients who underwent haplo-HSCT were analyzed. A significant difference in IL-6 levels was observed between the PTCy plus ATG and PTCy alone groups (7.47 ± 10.55 vs. 117.65 ± 127.67; p = 0.003). More patients in the PTCy plus ATG group had a CRS grade of 0 than in the PTCy alone group (p < 0.001). Serum IL-6 levels were associated with grades II–IV acute GVHD (r = 0.547, p < 0.001). The cumulative incidence (CI) of grades II–IV acute GVHD was significantly higher in the PTCy alone group (67.9% vs. 4.8%; p < 0.001). No significant difference in the CI for chronic GVHD was detected between the PTCy plus ATG and PTCy alone groups (72.1% vs. 82.0%; p = 0.730). The CI of 1-year non-relapse mortality was significantly higher in the PTCy alone group than in the PTCy plus ATG group (42.2% vs. 15.9%; p = 0.022). The 1-year overall survival (OS) was significantly better in the PTCy plus ATG group (75.9% vs. 35.3%; p = 0.011). The 1-year GVHD-free, relapse-free survival rate was 29.4% in the PTCy alone group and 54.0% in the PTCy plus ATG group (p = 0.038).
Conclusion
Serum IL-6 levels were higher in the PTCy alone group than in the PTCy plus ATG group. The addition of ATG before stem cell infusion affected IL-6 levels and reduced the incidences of CRS and grade II–IV acute GVHD in haplo-HSCT patients. This study suggests that PTCy plus ATG as GVHD prophylaxis in haplo-HSCT is beneficial in terms of clinical outcomes and complications of HSCT.
9.Perception on the Intestinal Malrotation: A 2021 Survey Conducted by the Korean Association of Pediatric Surgeons
Hee-Beom YANG ; Min Jeng CHO ; Yu Jeong CHO ; Yoon Mi CHOI ; Jae Hee CHUNG ; Seok Joo HAN ; Jeong HONG ; Eunyoung JUNG ; Ki Hoon KIM ; Soo-Hong KIM ; Cheol-Gu LEE ; Nam-Hyuk LEE ; Ju Yeon LEE ; Sanghoon LEE ; Suk Bae MOON ; Young-Hyun NA ; So Hyun NAM ; Chaeyoun OH ; Jin Young PARK ; Junbeom PARK ; Tae-Jin PARK ; Jae Ho SHIN ; Joonhyuk SON ; Hyun-Young KIM ;
Advances in Pediatric Surgery 2025;31(2):59-65
Purpose:
To report the findings of a perception survey on intestinal malrotation conducted by the Korean Association of Pediatric Surgeons (KAPS) in 2021.
Methods:
The perceptions on intestinal malrotation regarding clinical decision making of the KAPS members were collected through web-based survey.
Results:
A total of 22 surgeons were answered for this study. The results were presented and discussed at the 37th annual meeting of KAPS, which was held in Seoul on June 18, 2021.
Conclusion
This study provides the clinical decisions of the KAPS members on the intestinal malrotation. The study is expected to be an important reference for improving pediatric surgeons’ understanding and treatment of intestinal malrotation.
10.Eosinophilia Is a Favorable Marker for Pneumonia in Chronic Obstructive Pulmonary Disease
Kang-Mo GU ; Jae-Woo JUNG ; Min-Jong KANG ; Deog Kyeom KIM ; Hayoung CHOI ; Young-Jae CHO ; Seung Hun JANG ; Chang-Hoon LEE ; Yeon Mok OH ; Ji Sook PARK ; Jae Yeol KIM
Tuberculosis and Respiratory Diseases 2024;87(4):465-472
Background:
Patients with chronic obstructive pulmonary disease (COPD) expressing eosinophilia experience slightly fewer episodes of community-acquired pneumonia (CAP), than those without eosinophilia. However, the severity and burden of hospitalized pneumonia patients with COPD involving eosinophilia have not been assessed.
Methods:
We evaluated the differences in clinical characteristics between patients with CAP and COPD with or without eosinophilia by a post hoc analysis of a prospective, multi-center, cohort study data.
Results:
Of 349 CAP patients with COPD, 45 (12.9%) had eosinophilia (blood eosinophil ≥300 cells/μL). Patients with eosinophilia had a lower sputum culture percentile (8.1% vs. 23.4%, p<0.05), a lower percentile of neutrophils (70.3% vs. 80.2%, p<0.05), reduced C-reactive protein levels (30.6 mg/L vs. 86.6 mg/L, p<0.05), and a lower pneumonia severity index score (82.5 vs. 90.0, p<0.05), than those without eosinophilia. The duration of antibiotic treatment (8.0 days vs. 10.0 days, p<0.05) and hospitalization (7.0 days vs. 9.0 days, p<0.05) were shorter in eosinophilic patients. The cost of medical care per day (256.4 US$ vs. 291.0 US$, p<0.05), cost for the medication (276.4 US$ vs. 349.9 US$, p<0.05), and cost for examination (685.5 US$ vs. 958.1 US$, p<0.05) were lower in patients with eosinophilia than those without eosinophilia.
Conclusion
Eosinophilia serves as a favorable marker for the severity of pneumonia, health-care consumption, and cost of medical care in patients with CAP and COPD.

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