Objectives The household secondary attack rate (SAR) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important indicator for community transmission. This study aimed to characterize transmission by comparing household SARs and identifying risk factors during the periods of Delta and Omicron variant predominance in Republic of Korea.
Methods We defined the period of Delta variant predominance (Delta period) as July 25, 2021 to January 15, 2022, and the period of Omicron variant predominance (Omicron period) as February 7 to September 3, 2022. The number of index cases included was 214,229 for the Delta period and 5,521,393 for the Omicron period. To identify the household SARs and risk factors for each period, logistic regression was performed to determine the adjusted odds ratio (aOR).
Results The SAR was 35.2% for the Delta period and 43.1% for the Omicron period. The aOR of infection was higher in 2 groups, those aged 0 to 18 years and ≥75 years, compared to those aged 19 to 49 years. Unvaccinated individuals (vs. vaccinated individuals) and individuals experiencing initial infection (vs. individuals experiencing a second or third infection) had an increased risk of infection with SARS-CoV-2.
Conclusion This study analyzed the household SARs and risk factors. We hope that the results can help develop age-specific immunization plans and responses to reduce the SAR in preparation for emerging infectious diseases or potential new variants of SARS-CoV-2.
Objectives This study aimed to disseminate information on coronavirus disease 2019 (COVID-19) vaccine safety among adolescents aged 12 to 17 years in the Republic of Korea. Methods: Two databases were used to assess COVID-19 vaccine safety in adolescents aged 12 to 17 years who completed the primary Pfizer-BioNTech vaccination series. Adverse events reported to the web-based COVID-19 vaccination management system (CVMS) and collected in the text message-based system were analyzed. Results: From March 5, 2021 to February 13, 2022, 12,216 adverse events among 12- to 17-yearolds were reported to the CVMS, of which 97.1% were non-serious adverse events and 2.9% were serious adverse events, including 85 suspected cases of anaphylaxis, 74 suspected cases of myocarditis and/or pericarditis, and 2 deaths. From December 13, 2021 to January 26, 2022, 10,389 adolescents responded to a text message survey, and local/systemic adverse events were more common after dose 2 than after dose 1. The most commonly reported events following either vaccine dose were pain at the injection site, headache, fatigue/tiredness, and myalgia. Conclusion: The overall results are consistent with previous findings; the great majority of adverse events were non-serious, and serious adverse events were rare among adolescents aged 12 to 17 years following Pfizer-BioNTech COVID-19 vaccination.
Citations
Citations to this article as recorded by
Suspected Myocarditis after mRNA COVID-19 Vaccination among South Korean Adolescents Mi Jin Kim, Jin Hee Kim, Hyun Ok Jun, Kyung Min Kim, Min Sub Jeung, Jun Sung Park Journal of Pediatric Infectious Diseases.2024; 19(02): 075. CrossRef
Characterization of Brighton Collaboration criteria for myocarditis and pericarditis following COVID-19 vaccine in Korean adolescents Jue Seong Lee, HyoSug Choi, Seung Hwan Shin, Myung-Jae Hwang, Sara Na, Jong Hee Kim, Sangshin Park, Yoonsun Yoon, Hyun Mi Kang, Bin Ahn, Kyoungsan Seo, Young June Choe Vaccine.2024;[Epub] CrossRef
Immunogenicity, effectiveness, and safety of COVID-19 vaccines among children and adolescents aged 2–18 years: an updated systematic review and meta-analysis Peng Gao, Liang-Yu Kang, Jue Liu, Min Liu World Journal of Pediatrics.2023; 19(11): 1041. CrossRef
Incidence of myopericarditis after mRNA COVID-19 vaccination: A meta-analysis with focus on adolescents aged 12–17 years Bao-Qiang Guo, Hong-Bin Li, Li-Qiang Yang Vaccine.2023; 41(28): 4067. CrossRef
Safety monitoring of COVID-19 vaccines: February 26, 2021, To June 4, 2022, Republic of Korea Yeon-Kyeng Lee, Yunhyung Kwon, Yesul Heo, Eun Kyoung Kim, Seung Yun Kim, Hoon Cho, Seontae Kim, Mijeong Ko, Dosang Lim, Soon-Young Seo, Enhi Cho Clinical and Experimental Pediatrics.2023; 66(10): 415. CrossRef
Risk of Coronavirus Disease 2019 Messenger RNA Vaccination-Associated Myocarditis and Pericarditis – A Systematic Review of Population-Based Data Yen-Ching Lin, Chia-Hsuin Chang, Wei-Ju Su, Chin-Hui Yang, Jann-Tay Wang Risk Management and Healthcare Policy.2023; Volume 16: 2085. CrossRef
COVID-19 Vaccination in Korea: Past, Present, and the Way Forward Eliel Nham, Joon Young Song, Ji Yun Noh, Hee Jin Cheong, Woo Joo Kim Journal of Korean Medical Science.2022;[Epub] CrossRef