Background: To assess the mediation effect of gestational weight gain (GWG) and blood heavy metal levels in the late pregnancy affecting the association between early pregnancy metal exposure and fetal growth. Methods: We analyzed data from Korean Children’s Environmental Health Study cohort comprising 4,712 full-term births. Blood levels of lead (Pb), mercury (Hg), and cadmium (Cd) during pregnancy, and newborn birthweights were retrieved. We applied single-exposure model to assess the association between heavy metal levels and newborn anthropometric measures and conducted path analyses to examine the direct and indirect effects of heavy metal levels in early pregnancy on newborn measures. Results: Exposure to Pb (β = −15.470, P = 0.036) and Cd (β = −24.150, P = 0.004) during late pregnancy were associated with lower birthweight. Early exposure to Pb was not directly associated with lower birthweight, however, mediation of late exposure to Pb (β = −7.417, P = 0.049) resulted in lower birthweight (β = −14.787, P = 0.036). Early exposure to Hg was associated with higher birthweight, however, indirect paths via GWG (β = 3.626, P = 0.048) and late Hg levels (β = −12.929, P = 0.111) countered each other, resulting in the nullification of the total effect (β = −8.519, P = 0.301). Conclusion The effect of Pb exposure in early pregnancy on birthweight was mediated by GWG and Pb exposures during late pregnancy. When assessing the impact of heavy metal exposure on birthweight, it is important to note that GWG and late heavy metal levels act as mediators, rather than confounders.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

In mid-2022, as the wave of pediatric coronavirus disease 2019 (COVID-19) cases escalated in South Korea, a public-private partnership was made to establish a Pediatric COVID-19 Module Clinic (PMC). We describe the utilization of the first prototype children’s modular clinic in Korea University Anam Hospital functioning as the COVID-19 PMC. Between August 1 and September 30, 2022, a total of 766 children visited COVID-19 PMC. Daily number of patient visits to the COVID-19 PMC ranged between 10 and 47 in August; and less than 13 patients per day in September 2022. Not only the model provided timely care for the COVID-19 pediatric patients, but it also enabled safe and efficacious care for the non-COVID-19 patients in the main hospital building while minimizing exposure risk to severe acute respiratory syndrome coronavirus 2 transmission. Current description highlights the importance of spatial measures for mitigating in-hospital transmission of COVID-19, in specifically on pediatric care.