https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/51 2026-04-09T01:43:09Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/80386 Title: Epidemiological surveillance and genomic characterisation of betacoronavirus in Apodemus agrarius from Gyeonggi and Gangwon Provinces, Republic of Korea, 2017–2019 Authors: Kim, Jongwoo; No, Jin Sun; Park, Kyungmin; Lee, Seung-Ho; Natasha, Augustine; Pangestu, Haryo Seno; Klein, Terry A.; Kim, Heung Chul; Kim, Won-Keun; Song, Jin-Won Abstract: Coronaviruses (CoVs) infect a broad range of hosts and cause illnesses of varying severity, ranging from the common cold to severe acute respiratory syndrome, posing significant public health concerns. Although rodents are recognized as natural reservoirs of CoVs, genomic surveillance of rodent-borne Betacoronavirus(β-CoV) has not been conducted in the Republic of Korea (ROK). 511 Apodemus agrarius specimens collected in Gyeonggi and Gangwon Provinces between 2017 and 2019 were examined, with CoV RNA detected in 6.7% (34/511) of the intestinal tissue samples using reverse transcription polymerase chain reaction. This study represents the first molecular evidence of β-CoV in A. agrarius in the ROK. Phylogenetic analysis revealed two distinct genetic groups: A. agrarius CoV 1 (AaCoV-1) and AaCoV-2. The complete coding genome sequence of AaCoV-1 revealed the highest genomic similarity to China rat CoV HKU24, species B. ratti, and the subgenus Embecovirus. AaCoV-1 is predicted to have a high level of zoonotic potential, highlighting the need for epidemiological and pathogenic studies to assess its potential for human transmission. This report provides substantial insights into the molecular epidemiology, geographic distribution, and zoonotic potential of rodent-borne β-CoVs, contributing to a unified one health framework for the enhanced surveillance and risk control of emerging CoVs. © 2026 2026-03-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/79266 Title: Real-World Effectiveness of Seasonal Influenza Vaccines During the 2024-2025 Season: Subgroup Analyses by Virus Subtype, Time Since Vaccination, and Diagnostic Method Authors: Choi, Yu Jung; Lee, Jungmin; Song, Joon Young; Wie, Seong-Heon; Lee, Jacob; Lee, Jin-Soo; Jeong, Hye Won; Eom, Joong Sik; Sohn, Jang Wook; Yoon, Young Kyung; Choi, Won Suk; Nham, Eliel; Yoon, Jin Gu; Noh, Ji Yun; Park, Man-Seong; Cheong, Hee Jin Abstract: Background/Objectives: Despite high vaccination coverage, influenza remains a public health concern in South Korea, particularly in older adults. Continuous evaluation of vaccine effectiveness (VE) is essential to optimize immunization strategies. Methods: This study evaluated seasonal influenza VE for preventing laboratory-confirmed influenza using a test-negative design through a hospital-based influenza surveillance system in South Korea from 1 November 2024, to 30 April 2025. Demographic and clinical information was collected through questionnaire surveys and electronic medical records. Influenza was diagnosed using rapid antigen tests (RATs) and reverse transcription polymerase chain reaction (RT-qPCR), and vaccine effectiveness was analyzed using multivariable logistic regression. Results: In total, 3954 participants were included, with 1977 influenza-positive cases and 1977 test-negative controls. Influenza A and B accounted for 93.1% and 7.0% of cases, respectively. The adjusted overall VE was 20.4% (95% confidence interval [CI], 8.2-30.9; p = 0.002). VE was higher in adults aged 50-64 years (46.8%) than in those aged >= 65 years (18.8%). VE was 19.9% against influenza A and 45.7% against A/H3N2. VE was higher among individuals tested using RT-qPCR than among those tested using RATs (21.5% vs. 15.7%), and was also greater during the early period than during the late period (20.5% vs. 11.4%). Vaccination did not reduce influenza-associated hospitalization risk (VE, 17.3%; 95% CI, -9.3 to 37.4). A significant reduction in hospitalization risk was observed in adults aged 50-64 years (VE, 46.8%), with no significant benefit in those aged >= 65 years. Conclusions: The 2024-2025 seasonal influenza vaccine provided moderate protection against laboratory-confirmed influenza in adults, with higher effectiveness in those aged 50-64 years. 2026-01-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/79330 Title: Structure-guided design of a bivalent SARS-CoV-2 mRNA vaccine with NTD stabilizing mutations enhances broad immunity Authors: Yeo, Jinah; Yun, Mi-ran; Kim, Seo-Yeon; Seok, Jong-Hyun; Jeon, Ji Hyang; Lee, Taeyoung; Kim, Jeonghun; Kim, Kisoon; Park, Man-Seong; Kim, Dokeun; Kim, You-Jin Abstract: SARS-CoV-2 evolution, particularly the emergence of Omicron variants, has challenged vaccine efficacy, necessitating antigens with broad and variant-specific protection. To design mRNA vaccine antigens with broad-spectrum immunity and enhanced stability, we developed two spike antigens using in silico optimization: Css_dsg S, the ancestral strain-Delta variant consensus with stabilizing mutations, and Omi_dsg S, an Omicron-adapted design. Computational analysis identified two critical N-terminal domain stabilization sites consistently enhancing protein expression across variants, suggesting their potential as universal stabilizing elements. Css_dsg S elicited robust IFN-gamma T cell responses and significantly elevated neutralizing antibody titers against variants in BALB/c mice. Omi_dsg S induced strong immune responses in vivo. A bivalent mRNA vaccine combining both antigens elicited superior neutralizing antibody responses and conferred enhanced protection against BN.1 and BA.5 challenges in K18-hACE2 mice. These findings support computationally optimized spike antigens, particularly the bivalent formulation, as a promising strategy for next-generation vaccines against SARS-CoV-2 variants. 2026-01-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/76552 Title: Novel human coronavirus in an infant patient with pneumonia, Republic of Korea Authors: Park, Kyungmin; Shin, Minsoo; Natasha, Augustine; Kim, Jongwoo; Noh, Juyoung; Kim, Bohyeon; Park, Jieun; Kim, Seong-Gyu; Seo, Ye-Rin; Cho, Hee-Kyung; Byun, Kwan Soo; Kim, Ji Hoon; Lee, Young-Sun; Shim, Jung Ok; Kim, Won-Keun; Song, Jin-Won Abstract: Coronaviruses (CoVs) pose a significant threat to public health, causing a wide spectrum of clinical manifestations and outcomes. Beyond precipitating global outbreaks, Human CoVs (HCoVs) are frequently found among patients with respiratory infections. To date, limited attention has been directed towards alphacoronaviruses due to their low prevalence and fatality rates. Nasal swab and serum samples were collected from a paediatric patient, and an epidemiological survey was conducted. Retrospective surveillance investigated the molecular prevalence of CoV in 880 rodents collected in the Republic of Korea (ROK) from 2018 to 2022. Next-generation sequencing (NGS) and phylogenetic analyses characterized the novel HCoV and closely related CoVs harboured by Apodemus spp. On 15 December 2022, a 103-day-old infant was admitted with fever, cough, sputum production, and rhinorrhea, diagnosed with human parainfluenza virus 1 (HPIV-1) and rhinovirus co-infection. Elevated AST/ALT levels indicated transient liver dysfunction on the fourth day of hospitalization. Metagenomic NGS (mNGS) identified a novel HCoV in nasal swab and serum samples. Retrospective rodent surveillance and phylogenetic analyses showed the novel HCoV was closely related to alphacoronaviruses carried by Apodemus spp. in the ROK and China. This case highlights the potential of mNGS to identify emerging pathogens and raises awareness of possible extra-respiratory manifestations, such as transient liver dysfunction, associated with novel HCoVs. While the liver injury in this case may be attributable to the novel HCoV, further research is necessary to elucidate its clinical significance, epidemiological prevalence, and zoonotic origins. 2025-12-01T00:00:00Z