During the coronavirus disease 2019 (COVID-19) pandemic, conclusively evaluating possible associations between COVID-19 vaccines and potential adverse events was of critical importance. The National Academy of Medicine of Korea established the COVID-19 Vaccine Safety Research Center (CoVaSC) with support from the Korea Disease Control and Prevention Agency to investigate the scientific relationship between COVID-19 vaccines and suspected adverse events. Although determining whether the COVID-19 vaccine was responsible for any suspected adverse event necessitated a systematic approach, traditional causal inference theories, such as Hill's criteria, encountered certain limitations and criticisms. To facilitate a systematic and evidence-based evaluation, the United States Institute of Medicine, at the request of the Centers for Disease Control and Prevention, offered a detailed causality assessment framework in 2012, which was updated in the recent report by the National Academies of Sciences, Engineering, and Medicine (NASEM) in 2024.This framework, based on a weight-of-evidence approach, allows the independent evaluation of both epidemiological and mechanistic evidence, culminating in a comprehensive conclusion about causality. Epidemiological evidence derived from population studies is categorized into four levels—high, moderate, limited, or insufficient—while mechanistic evidence, primarily from biological and clinical studies in animals and individuals, is classified as strong, intermediate, weak, or lacking. The committee then synthesizes these two types of evidence to draw a conclusion about the causal relationship, which can be described as “convincingly supports” (“evidence established” in the 2024 NASEM report), “favors acceptance,” “favors rejection,” or “inadequate to accept or reject.” The CoVaSC has established an independent committee to conduct causality assessments using the weightof-evidence framework, specifically for evaluating the causality of adverse events associated with COVID-19 vaccines. The aim of this study is to provide an overview of the weight-ofevidence framework and to detail the considerations involved in its practical application in the CoVaSC.

The COVID-19 Vaccine Safety Research Committee (CoVaSC) was established in November 2021 to address the growing need for independent, in-depth scientific evidence on adverse events (AEs) following coronavirus disease 2019 (COVID-19) vaccination. This initiative was requested by the Korea Disease Control and Prevention Agency and led by the National Academy of Medicine of Korea. In September 2022, the COVID-19 Vaccine Safety Research Center was established, strengthening CoVaSC’s initiatives. The center has conducted various studies on the safety of COVID-19 vaccines. During CoVaSC’s second research year, from September 29, 2022 to July 19, 2023, the center was restructured into 4 departments: Epidemiological Research, Clinical Research, Communication & Education, and International Cooperation & Policy Research. Its main activities include (1) managing CoVaSC and the COVID-19 Vaccine Safety Research Center, (2) surveying domestic and international trends in AE causality investigation, (3) assessing AEs following COVID-19 vaccination, (4) fostering international collaboration and policy research, and (5) organizing regular fora and training sessions for the public and clinicians. Causality assessments have been conducted for 27 diseases, and independent research has been conducted after organizing ad hoc committees comprising both epidemiologists and clinical experts on each AE of interest. The research process included protocol development, data analysis, interpretation of results, and causality assessment. These research outcomes have been shared transparently with the public and healthcare experts through various fora. The COVID-19 Vaccine Safety Research Center plans to continue strengthening and expanding its research activities to provide reliable, high-quality safety information to the public.

With the introduction of coronavirus disease 2019 (COVID-19) vaccines, the Korea Disease Control and Prevention Agency (KDCA) commissioned the National Academy of Medicine of Korea to gather experts to independently assess post-vaccination adverse events. Accordingly, the COVID-19 Vaccine Safety Research Committee (CoVaSC) was launched in November 2021 to perform safety studies and establish evidence for policy guidance. The CoVaSC established 3 committees for epidemiology, clinical research, and communication. The CoVaSC mainly utilizes pseudonymized data linking KDCA’s COVID-19 vaccination data and the National Health Insurance Service’s claims data. The CoVaSC’s 5-step research process involves defining the target diseases and organizing ad-hoc committees, developing research protocols, performing analyses, assessing causal relationships, and announcing research findings and utilizing them to guide compensation policies. As of 2022, the CoVaSC completed this research process for 15 adverse events. The CoVaSC launched the COVID-19 Vaccine Safety Research Center in September 2022 and has been reorganized into 4 divisions to promote research including international collaborative studies, long-/short-term follow-up studies, and education programs. Through these enhancements, the CoVaSC will continue to swiftly provide scientific evidence for COVID-19 vaccine research and compensation and may serve as a model for preparing for future epidemics of new diseases.

Purpose: In delayed myelopathy (DM) from osteoporotic vertebral compression fractures (OVCF), the mechanisms of spinal cord impingement differ according to the stability of the fractured vertebra. This study examined the availability of a posterior surgery comprised of pedicle screw augmentation with polymethylmethacrylate (PMMA) and selective anterior reinforcement (PS-PMMA+SAR) according to the stability. Materials and Methods: This was a retrospective single-center study. The consecutive patients who had a PS-PMMA+SAR for a DM from OVCF and were followed up more than two years were reviewed. Thirty patients were eligible for this study. All patients used fenestrated screws for PMMA augmentation. Anterior reinforcement was selected according to the stability. The unstable type was done by filling the vacuum cleft with bone chips or PMMA, and the stable type was done by vertebral body anterior translation with/without an interbody bone graft. The radiological and functional outcomes were evaluated. Results: There were 20 unstable and 10 stable cases. The regional kyphotic angle was improved significantly from 31.3°±10.8° to 10.4°±8.3° (p<0.001). The anterior vertebral height ratio was improved significantly from 39.4%±17.1% to 86.4%±9.2% (p<0.001). The spinal canal invasion ratio was improved significantly from 39.2%±14.8% to 19.1%±10.8% (p<0.001). The walking ability was improved mostly by two Nurick’s grades (p<0.001). The Oswestry disability index was improved from 72% to 33% (p<0.001). Conclusion Posterior surgery with PMMA-augmented pedicle screws, and selective anterior reinforcement for DM from OVCF was available to achieve a good functional and radiological outcome.

The nose is a complex three-dimensional structure and represents a major aesthetic focus of the face. As a gold standard for nasal soft tissue reconstruction, the ‘forehead flap’ provides reconstructive surgeons a robust pedicle and large amount of tissue to reconstruct almost any defect. However, during this process, some hair can be unintentionally introduced to the nose. Accordingly, laser hair removal is sometimes needed, but blood circulation and flap survival should be carefully monitored.Despite careful evaluation, a third-degree burn occurred in our patient that required eight weeks to heal. Here, we report on a burn resulting from epilation conducted 2 weeks after forehead flap for nasal reconstruction.

The nose is a complex three-dimensional structure and represents a major aesthetic focus of the face. As a gold standard for nasal soft tissue reconstruction, the ‘forehead flap’ provides reconstructive surgeons a robust pedicle and large amount of tissue to reconstruct almost any defect. However, during this process, some hair can be unintentionally introduced to the nose. Accordingly, laser hair removal is sometimes needed, but blood circulation and flap survival should be carefully monitored.Despite careful evaluation, a third-degree burn occurred in our patient that required eight weeks to heal. Here, we report on a burn resulting from epilation conducted 2 weeks after forehead flap for nasal reconstruction.

Purpose: This study examined the radiological and clinical outcomes of internal fixation using a reconstruction plate and 21G circumferential wire in comminuted midshaft clavicular fractures. Materials and Methods: A retrospective cohort study was performed on 51 patients between 2005 and 2019. Thirty-two patients underwent internal fixation with a reconstruction plate and a 21G circumferential wire with minimal soft tissue detachment, and 19 patients underwent surgery without a wire. The patients were assessed with the radiographic parameters, the University of California at Los Angeles (UCLA) score, and the visual analogue scale (VAS) pain score. Based on this, patients who operated without a circumferential wire were set as the control group, and the differences in bone union between the two groups were compared. Results: Thirty-two patients were followed-up for an average of 65 weeks, and 19 patients in the control group were followed-up for an average of 56 weeks. The radiological evaluation confirmed the anatomical reduction and bone union in all 32 patients. No case of nonunion was present. The UCLA score was 32.38 on average and 33.11 in the control group (p=0.395). The VAS score was 1.00 on average and 0.84 in the control group (p=0.668). A significant difference in the bony union time was observed between the group who underwent internal fixation with a reconstruction plate and a 21G circumferential wire with minimal soft tissue detachment, and the control group (p=0.015). On the other hand, there was no statistical significance when other variables were controlled (p=0.107). Conclusion For displaced midshaft clavicular fractures, internal fixation using a reconstruction plate and 21G circumferential wire maintained accurate anatomical reduction. The satisfactory clinical and radiological results mean that internal fixation using a reconstruction plate and 21G circumferential wire may be a good option for surgical treatment.

Background: Pedicle screw augmentation with bone cement has been experimentally demonstrated to increase the pullout strength. However, the mechanisms of screw loosening are complicated and interacting. Although vertebroplasty augmentation and fenestrated screw augmentation have been compared in many studies, there has been no comparative study on their clinical effects and complications in real clinical settings. We investigated clinical effects of bone cement augmentation of a pedicle screw and differences according to augmentation methods. Methods: Of the total 241 patients who had osteoporosis and underwent posterior pedicle screw fixation without anterior bone graft between January 2010 and December 2016, 132 patients with ≥2 years of radiological follow-up were included in this retrospective study. The patients were divided into group I (unaugmented) and group II (bone cement augmented). Group II was subdivided into II-S group (solid screw augmented) and II-F group (fenestrated screw augmented). The incidence of screw loosening was compared between groups I and II. Cement leakage, screw loosening, and screw fractures were investigated in the subgroups. Results: In total, 36 of 71 (52%, group I) unaugmented cases and 96 of 170 (56%, group II) augmented cases were followed up for ≥2 years. Of the total 78 solid screw augmented cases, 42 (56%) were in II-S group; 54 of the total 92 (59%) fenestrated screw augmented cases were in II-F group. Groups I and II were homogenous regarding demographic characteristics; II-S and II-F groups were also homogenous. The incidence of screw loosening was 50.0% (18/36) in group I and 7.3% (7/96) in group II (p < 0.001). Cement leakage developed in 2 of 42 (4.8%) cases in II-S group and in 5 of 54 (9.3%) cases in II-F group (p = 0.462). Screw loosening developed in 6 of 42 (14.3%) cases in II-S group and in 1 of 54 cases (1.9%) in II-F group (p = 0.041). Screw fracture developed in none of 42 cases in II-S group and in 3 of 54 cases (5.6%) in II-F group (p = 0.254). Conclusions In osteoporotic patients, bone cement augmentation of a pedicle screw decreased the incidence of screw loosening, and fenestrated screw augmentation was more effective than vertebroplasty augmentation.

BACKGROUND: Spinal diseases are self-limited or non-progressive in many cases. Epidural steroid injection (ESI) is a common nonsurgical treatment option for spinal pain. Despite concerns about complications of repeated steroid injection, few studies reported on the adrenal function of spine disease patients undergoing surgery after ESI. We investigated the influence of preoperative multiple ESIs on adrenal function in spine surgery patients. METHODS: This was a retrospective study with prospective data collection. Those who underwent elective spinal operations and had a history of multiple ESIs from January to June 2017 were selected as a study group. Those who underwent knee arthroplasty and did not have a history of ESI and any kind of steroid injection in other areas during 6 months before surgery were selected as a control group. Demographic data were compared to assess homogeneity between groups. We assessed the preoperative serum cortisol level (SCL) to compare the basal adrenal function between groups. Also, we assessed the elevation of SCL postoperatively to evaluate the adrenal response to the surgical stress in each group. For subgroup analysis, we divided all patients into normal (7–28 µg/dL) and subnormal groups according to SCL and analyzed risk factors of adrenal suppression with multivariate logistic regression test. RESULTS: There were 53 patients in the study group and 130 in the control group. Age and sex were homogeneous between groups. There was significant intergroup difference in preoperative SCL (10.4 ± 4.8 µg/dL in the study group vs. 12.0 ± 4.2 µg/dL in the control group; p = 0.026).The postoperative day one SCL was 11.6 ± 5.0 µg/dL in the study group without significant increase from the preoperative level (p = 0.117), whereas the increase was significant in the control group with a postoperative level of 14.4 ± 4.4 µg/dL (p < 0.001). Among all patients, the SCL was subnormal in 18 patients and within the normal range in 165. Spine surgery was the independent risk factor irrespective of age and sex (odds ratio, 3.472; p = 0.015). CONCLUSIONS: Our results suggest that concern should be raised about the influence of preoperative multiple ESIs on adrenal suppression in spine surgery patients.
Arthroplasty, Replacement, Knee ; Data Collection ; Humans ; Hydrocortisone ; Logistic Models ; Prospective Studies ; Reference Values ; Retrospective Studies ; Risk Factors ; Spinal Diseases ; Spine

Mixed-species malaria infections are often unrecognized or underestimated. We hereby report the first described case of mixed infection with Plasmodium falciparum and Plasmodium ovale malaria in a returned traveller in Korea. In August 2016, a 25-year-old returned traveller from Cameroon and Democratic Republic of Congo presented with fever. He was diagnosed as P. falciparum malaria and successfully treated with artesunate. And 5 weeks after the completion of treatment, he presented with fever and diagnosed as P. ovale infection. P. ovale infection is a rare cause of malaria and often shows delayed presentation due to its dormant liver stage as hypnozoites. At re-presentation, the immunochromatographic test and microscopic examinations of our patient did not reveal P. ovale, which was only detected via polymerase chain reaction (PCR) assay. This case highlights the importance of considering malaria infection even in persons who have previously received malaria treatment. It also shows the usefulness of PCR testing for diagnosing P. ovale infections, which often present with a low level of parasitaemia.
Adult ; Cameroon ; Coinfection* ; Congo ; Fever ; Humans ; Korea* ; Liver ; Malaria ; Plasmodium falciparum* ; Plasmodium ovale* ; Plasmodium* ; Polymerase Chain Reaction