https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/51 2026-04-03T23:32:53Z 2026-04-03T23:32:53Z 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 https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/79266 2026-02-10T06:01:12Z 2026-01-01T00:00:00Z

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 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 https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/79330 2026-02-25T02:30:33Z 2026-01-01T00:00:00Z

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 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 https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/76552 2025-11-12T06:01:58Z 2025-12-01T00:00:00Z

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 Choi, Min Joo Gwak, Wonseok Yun, Jae Young Ju, Hae Jeon Choi, Eunjoo Cheong, Hee Jin Kim, Woo Joo Kim, Chulwoo Kim, Hwa Jung Jang, A-Yeung Yoon, Sunkyung Lee, June-Woo Jeong, Hye-Sook Song, Joon Young https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/79106 2026-01-26T08:30:26Z 2025-12-01T00:00:00Z

Title: Exploratory evidence of mitigated immune imprinting following concomitant COVID-19 and influenza vaccination Authors: Choi, Min Joo; Gwak, Wonseok; Yun, Jae Young; Ju, Hae Jeon; Choi, Eunjoo; Cheong, Hee Jin; Kim, Woo Joo; Kim, Chulwoo; Kim, Hwa Jung; Jang, A-Yeung; Yoon, Sunkyung; Lee, June-Woo; Jeong, Hye-Sook; Song, Joon Young Abstract: Concomitant administration of coronavirus disease (COVID-19) and influenza vaccination schedules has been widely adopted. However, long-term data on the immunological impact, particularly on variant-specific responses, remain limited. In this 10-month prospective study, 80 participants (40 per group) received either a concomitant bivalent COVID-19 mRNA booster and quadrivalent influenza vaccination (Group C) or separate vaccinations (Group S) at least 4 weeks apart. Immunogenicity was evaluated using an anti-S IgG electrochemiluminescence immunoassay, anti- receptor-binding domain (RBD) IgG enzyme-linked immunosorbent assay, focus reduction neutralisation test (FRNT), and hemagglutination-inhibition assay. Both Groups C and S elicited robust immune responses for up to 10 months with no immune interference, as antibody responses against wild-type (WT) and Omicron BA.5 remained comparable between the groups. Notably, neutralising antibody titre against Omicron BA.5 were higher in Group C at 1 month post-vaccination, with significantly higher neutralising potency (FRNT50/anti-RBD IgG titer ratio) against Omicron BA.5 and a higher BA.5-to-WT ratio in FRNT. These findings may suggest alleviated immune imprinting, although this remains exploratory and requires further validation. For influenza, the overall antibody responses were comparable between the two groups. These findings support the feasibility of concomitant influenza and COVID-19 vaccination, without evidence of immune interference. Moreover, the enhanced variant-specific immune responses with concomitant administration suggest a potential immunological benefit, warranting future investigation.

2025-12-01T00:00:00Z