COVID-19, maternal, and neonatal outcomes: National Mother-Child Cohort (NMCC) of K-COV-N cohort in South Korea.

Throughout the COVID-19 pandemic, pregnant women have been classified as a vulnerable population. However, the evidence on the effect of infection during pregnancy on maternal and neonatal outcomes is still uncertain, and related research comprising a large population of pregnant women in Asian countries is limited. We constructed a national cohort including mothers and children (369,887 pairs) registered in the Prevention Agency-COVID-19-National Health Insurance Service (COV-N), from January 1, 2020 to March 31, 2022. We performed propensity score matchings and generalized estimation equation models to estimate the effect of COVID-19 on maternal and neonatal outcomes. In summary, we found little evidence of the effect of COVID-19 infection during pregnancy on maternal and neonatal outcomes; however, a relationship between COVID-19 infection in the second trimester and postpartum hemorrhages was discovered (Odds ratio (OR) of Delta period: 2.26, 95% Confidence intervals (CI): 1.26, 4.05). In addition, neonatal intensive care unit (NICU) admissions increased due to COVID-19 infection (pre-Delta period: 2.31, 95% CI: 1.31, 4.10; Delta period: 1.99, 95% CI: 1.47, 2.69; Omicron period: 2.36, 95% CI: 1.75, 3.18). Based on the national retrospective cohort study data, this study investigated the effects of COVID-19 infection on maternal and neonatal outcomes in Korea from the pre-Delta to the initial Omicron epidemic periods. Our evidence suggests that the timely and successful policies of the government and academia in response to COVID-19 infections in newborns in Korea may cause an increase in NICU admissions, but nonetheless, they prevent adverse maternal and neonatal outcomes simultaneously.

A framework for nationwide COVID-19 vaccine safety research in the Republic of Korea: the COVID-19 Vaccine Safety Research Committee.

With the introduction of coronavirus disease 2019 (COVID-19) vaccines, the Korea Disease Control and Prevention Agency (KDCA) commissioned the National Academy of Medicine of Korea to gather experts to independently assess post-vaccination adverse events. Accordingly, the COVID-19 Vaccine Safety Research Committee (CoVaSC) was launched in November 2021 to perform safety studies and establish evidence for policy guidance. The CoVaSC established 3 committees for epidemiology, clinical research, and communication. The CoVaSC mainly utilizes pseudonymized data linking KDCA's COVID-19 vaccination data and the National Health Insurance Service's claims data. The CoVaSC's 5-step research process involves defining the target diseases and organizing ad-hoc committees, developing research protocols, performing analyses, assessing causal relationships, and announcing research findings and utilizing them to guide compensation policies. As of 2022, the CoVaSC completed this research process for 15 adverse events. The CoVaSC launched the COVID-19 Vaccine Safety Research Center in September 2022 and has been reorganized into 4 divisions to promote research including international collaborative studies, long-/short-term follow-up studies, and education programs. Through these enhancements, the CoVaSC will continue to swiftly provide scientific evidence for COVID-19 vaccine research and compensation and may serve as a model for preparing for future epidemics of new diseases.

Changes in eating behaviors according to household income in adolescents during the COVID-19 pandemic: Findings from the Korea National Health and Nutrition Examination Survey.

Objectives: To assess the social inequalities in changes of dietary behaviors among adolescents during the COVID-19 pandemic, we compared changes in dietary behavior indicators by household income. Methods: Using cross-sectional data from the 2019 and 2020 Korea National Health and Nutrition Examination Survey, the prevalence of dietary behaviors in adolescents (12-18 years old) was estimated and changes in dietary behaviors before and after the COVID-19 pandemic were evaluated. We assessed changes in dietary behaviors with a household income (as a measure of socioeconomic status [SES]) disparity. Results: During the COVID-19 pandemic, average consumption of vegetables has decreased and food insecurity has worsened. Adolescents were more likely to skip breakfast than before COVID-19 (33.1 % and 37.4 %). Soft drink consumption also increased in 2020 than in 2019 (7.6 % and 14.8 %), especially among boys. Average sugar intake and sodium intake showed a tendency to decrease only in girls, but there was no difference according to SES level. Skip breakfast was particularly evident in the low SES group, and the difference according to household income level (high vs. low) was greater after COVID-19 than before. The prevalence of soft drink consumption increased significantly in low SES group, but the rate of increase did not differ by SES level. Conclusion: We found that the social disparity in skipping breakfast was further aggravated. For a better understanding of the dietary behaviors of adolescents, continuous monitoring is necessary.

Developing a Framework for Pandemic COVID-19 Vaccine Allocation: a Modified Delphi Consensus Study in Korea.

BACKGROUND: This study presents a framework for determining the allocation and distribution of the limited amount of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: After analyzing the pandemic strategies of the major organizations and countries and with a literature review conducted by a core panel, a modified Delphi survey was administered to 13 experts in the fields of vaccination, infectious disease, and public health in the Republic of Korea. The following topics were discussed: 1) identifying the objectives of the vaccination strategy, 2) identifying allocation criteria, and 3) establishing a step-by-step vaccination framework and prioritization strategy based on the allocation criteria. Two rounds of surveys were conducted for each topic, with a structured questionnaire provided via e-mail in the first round. After analyzing the responses, a meeting with the experts was held to obtain consensus on how to prioritize the population groups. RESULTS: The first objective of the vaccination strategy was maintenance of the integrity of the healthcare system and critical infrastructure, followed by reduction of morbidity and mortality and reduction of community transmission. In the initial phase, older adult residents in care homes, high-risk health and social care workers, and personal support workers who work in direct contact with coronavirus disease 2019 (COVID-19) patients would be prioritized. Expansion of vaccine supply would allow immunization of older adults not included in phase 1, followed by healthcare workers not previously included and individuals with comorbidities. Further widespread vaccine supply would ensure availability to the extended adult age groups (50-64 years old), critical workers outside the health sector, residents who cannot socially distance, and, eventually, the remaining populations. CONCLUSION: This survey provides the much needed insight into the decision-making process for vaccine allocation at the national level. However, flexibility in adapting to strategies will be essential, as new information is constantly emerging.

Years of Life Lost Attributable to COVID-19 in High-incidence Countries.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is a major public health problem of international concern. It is important to estimate its impact of COVID-19 for health policy decision-making. We estimated the years of life lost (YLLs) due to COVID-19 in high-incidence countries. METHODS: We collected the YLLs due to COVID-19 in 30 high-incidence countries as of April 13, 2020 and followed up as of July 14, 2020. Incidence and mortality were collected using each country's formal reports, articles, and other electronic sources. The life expectancy of Japanese females by age and the UN population data were used to calculate YLLs in total and per 100,000. RESULTS: As of April 22, 2020, there were 1,699,574 YLLs due to COVID-19 in 30 high-incidence countries. On July 14, 2020, this increased to 4,072,325. Both on April 22 and July 14, the total YLLs due to COVID-19 was highest in the USA (April 22, 534,481 YLLs; July 14, 1,199,510 YLLs), and the YLLs per 100,000 population was highest in Belgium (April 22, 868.12 YLLs/100,000; July 14, 1,593.72 YLLs/100,000). YLLs due to COVID-19 were higher among males than among females and higher in those aged ≥ 60 years than in younger individuals. Belgium had the highest proportion of YLLs attributable to COVID-19 as a proportion of the total YLLs and the highest disability-adjusted life years per 100,000 population. CONCLUSION: This study estimated YLLs due to COVID-19 in 30 countries. COVID-19 is a high burden in the USA and Belgium, among males and the elderly. The YLLs are very closely related with the incidence as well as the mortality. This highlights the importance of the early detection of incident case that minimizes severe acute respiratory syndrome coronavirus-2 fatality.

The Burden of Disease due to COVID-19 in Korea Using Disability-Adjusted Life Years.

BACKGROUND: The world is currently experiencing a pandemic of coronavirus disease 2019 (COVID-19). In Korea, as in other countries, the number of confirmed cases and deaths due to COVID-19 have been rising. This study aimed to calculate the burden of disease due to COVID-19 in Korea. METHODS: We used data on confirmed cases and deaths due to COVID-19 between January 20 and April 24, 2020 provided by the Korea Centers for Disease Control and Prevention, the local governments and the public media to determine disability-adjusted life years (DALYs) by sex and age. Morbidity was estimated directly among the confirmed, cured, and fatal cases. Disability weights were adopted from previous similar causes on the severity of COVID-19 for the years of life lived with disability (YLDs). The years of life lost (YLLs) were calculated using the standard life expectancy from the 2018 life tables for each sex and age. RESULTS: The YLDs were higher in females (155.2) than in males (105.1), but the YLLs were higher in males (1,274.3) than in females (996.4). The total disease burden attributable to COVID-19 in Korea during the study period, was estimated to be 2,531.0 DALYs, and 4.930 DALYs per 100,000 population. The YLDs and the YLLs constituted 10.3% and 89.7% of the total DALYs, respectively. The DALYs per 100,000 population were highest in people aged ≥ 80 years, followed by those aged 70-79, 60-69, and 50-59 years, but the incidence was the highest in individuals aged 20-29 years. CONCLUSION: This study provided the estimates of DALYs due to COVID-19 in Korea. Most of the disease burden from COVID-19 was derived from YLL; this indicates that decision-makers should focus and make an effort on reducing fatality for preparing the second wave of COVID-19.