Objectives With the recent global mpox outbreak, the JYNNEOS vaccine (Modified Vaccinia Ankara-Bavarian Nordic) was developed as a third-generation smallpox vaccine and initially favored for mpox immunization. Vaccine-associated side effects contribute to vaccine hesitancy. Consequently, tracking adverse events post-immunization is crucial for safety management. This study used data from the national active vaccine safety surveillance conducted in Korea from August 25 to November 24, 2022 to detect potential safety signals and adverse events. Methods: Data on health conditions following vaccination were gathered from web-based surveys and reported via active surveillance through the Immunization Registry Information System. This follow-up system functioned via a text message link, surveying adverse events and health conditions beginning on the second day post-vaccination. Information about specific adverse events, including both local and systemic reactions, was collected. Results: The study included 86 healthcare workers who had received at least 1 dose of the JYNNEOS vaccine. Among the respondents, 79.1% reported experiencing at least 1 adverse event, with the majority being local reactions at the injection site. The incidence of adverse events was higher following the first dose (67.9%) than after the second dose (34.4%). The most frequently reported adverse event for both doses was mild pain at the injection site. Conclusion: The study provides crucial information on the safety of the JYNNEOS vaccine, demonstrating that most adverse events were manageable and predominantly localized to the injection site. Nonetheless, additional research is needed on the safety of various vaccine administration techniques and the vaccine’s effects on broader demographics.
Citations
Citations to this article as recorded by
Enhanced Immunogenicity and Affinity with A35R-Fc-Based Chimeric Protein Compared to MPXV A35R Protein Shimeng Bai, Yanxin Cui, Qibin Liao, Hongyang Yi, Zhonghui Liao, Gengwei Zhang, Fenfang Wu, Hongzhou Lu Viruses.2025; 17(1): 116. CrossRef
The Role of Adverse Event Follow-Up in Advancing the Knowledge of Medicines and Vaccines Safety: A Scoping Review Vijay Kara, Florence Van Hunsel, Andrew Bate, Eugène van Puijenbroek Drug Safety.2025; 48(9): 977. CrossRef
Potential of MRNA vaccines for mpox prevention: current evidence and future directions Toufik Abdul-Rahman, Ogungbemi Evelyn Faith, Oyinbolaji Akinwande Ajetunmobi, Hala Ibrahim Thaalibi, Chinelo Geraldine Ikele, Gargi Gautam, Faith Olanrewaju Omotayo, Poulami Roy, Alhazan Amir Adebayo, Muslimat Abolore Mojeed, Tolulope Taiwo Kareem, Halima Annals of Medicine & Surgery.2025; 87(9): 5650. CrossRef
Adverse Reactions After Intradermal Vaccination With JYNNEOS for Mpox in Korea So Yun Lim, Yu Mi Jung, Yeonjae Kim, Gayeon Kim, Jaehyun Jeon, BumSik Chin, Min-Kyung Kim Journal of Korean Medical Science.2024;[Epub] CrossRef
First Nationwide Mpox Vaccination Program in the Republic of Korea: Implications for an Enhanced Public Health Response Seunghyun Lewis Kwon, Minju Song, Wonkyung Lee, Jeeyeon Shin, Su-Yeon Lee, Sang-Gu Yeo, Minjeong Kim, Sanggyun Jeong, Joonku Park, Dongwoo Lee, Sookyoung Lim Journal of Korean Medical Science.2024;[Epub] CrossRef
Global perspectives on smallpox vaccine against monkeypox: a comprehensive meta-analysis and systematic review of effectiveness, protection, safety and cross-immunogenicity Hao Liu, Wenjing Wang, Yang Zhang, Fuchun Wang, Junyi Duan, Tao Huang, Xiaojie Huang, Tong Zhang Emerging Microbes & Infections.2024;[Epub] CrossRef
Objectives On February 16, 2022, 12 cases of hepatitis E virus (HEV) infection were reported in a food manufacturing factory in Korea. The aim of this study was to identify additional cases and to determine the source of this HEV outbreak. Methods: This study was an in-depth investigation of 12 HEV immunoglobulin M (IgM)-positive cases and their demographic, clinical, and epidemiological characteristics. On-site specimens were collected from the environment and from humans, and a follow-up investigation was conducted 2 to 3 months after the outbreak. Results: Among 80 production workers in the factory, 12 (15.0%) had acute HEV infection, all of whom were asymptomatic. The follow-up investigation showed that 3 cases were HEV IgMpositive, while 6 were HEV IgG-positive. HEV genes were not detected in the HEV IgM-positive specimens. HEV genes were not detected in the food products or environmental specimens collected on-site. HEV was presumed to be the causative pathogen. However, it could not be confirmed that the source of infection was common consumption inside the factory. Conclusion: This was the first domestic case of an HEV infection outbreak in a food manufacturing factory in Korea. Our results provide information for the future control of outbreaks and for the preparation of measures to prevent domestic outbreaks of HEV infection.
Citations
Citations to this article as recorded by
Current global estimates, risk factors, and knowledge gaps for Hepatitis E virus (HEV): A scoping review Md Koushik Ahmed, Hanna Maroofi, Madeleine Blunt, Alain Labrique, Carl Kirkwood, Kirsten Vannice, Kawsar R. Talaat, Julia Lynch, Brittany L. Kmush, David Safronetz PLOS Neglected Tropical Diseases.2026; 20(3): e0013980. CrossRef
First
Prev
