Background: Myasthenia gravis (MG) is a rare classic autoimmune disease where immunosuppressant therapies have been successful to reduce MG attributable mortality fairly well. However, patients with refractory MG (rMG) among the actively treated MG (aMG) are nonresponsive to conventional therapy and display high disease severity, which calls for further research. We aimed to determine survival, prognosis, and clinical feature of patients with rMG compared to non-rMG. Methods: Retrospective nationwide cohort study using Korea's healthcare database between 2002 and 2017 was conducted. Patients with rMG (n = 47) and non-rMG (n = 4,251) who were aged > 18 years, followed-up for ≥ 1 year, and prescribed immunosuppressants within 2 years after incident MG diagnosis were included. Patients with rMG were defined as administered plasma exchange or intravenous immunoglobulin at least 3 times per year after receiving ≥ 2 immunosuppressants. All-cause mortality, myasthenic crisis, hospitalization, pneumonia/ sepsis, and emergency department (ED) visits were measured using Cox proportional hazard models and pharmacotherapy patterns for rMG were assessed. Results: The rMG cohort included a preponderance of younger patients and women. The adjusted hazard ratio was 2.49 (95% confidence interval, 1.26–4.94) for mortality, 3.14 (2.25–4.38) for myasthenic crisis, 1.54 (1.15–2.06) for hospitalization, 2.69 (1.74–4.15) for pneumonia/sepsis, and 1.81 (1.28–2.56) for ED visits for rMG versus non-rMG. The immunosuppressant prescriptions were more prevalent in patients with rMG, while the difference was more remarkable before rMG onset rather than after rMG onset. Conclusion Despite the severe prognosis of rMG, the strategies for pharmacotherapeutic regimens were similar in those two groups, suggesting that intensive monitoring and introduction of timely treatment options in the early phase of MG are required.

Background: Myasthenia gravis (MG) is a rare classic autoimmune disease where immunosuppressant therapies have been successful to reduce MG attributable mortality fairly well. However, patients with refractory MG (rMG) among the actively treated MG (aMG) are nonresponsive to conventional therapy and display high disease severity, which calls for further research. We aimed to determine survival, prognosis, and clinical feature of patients with rMG compared to non-rMG. Methods: Retrospective nationwide cohort study using Korea's healthcare database between 2002 and 2017 was conducted. Patients with rMG (n = 47) and non-rMG (n = 4,251) who were aged > 18 years, followed-up for ≥ 1 year, and prescribed immunosuppressants within 2 years after incident MG diagnosis were included. Patients with rMG were defined as administered plasma exchange or intravenous immunoglobulin at least 3 times per year after receiving ≥ 2 immunosuppressants. All-cause mortality, myasthenic crisis, hospitalization, pneumonia/ sepsis, and emergency department (ED) visits were measured using Cox proportional hazard models and pharmacotherapy patterns for rMG were assessed. Results: The rMG cohort included a preponderance of younger patients and women. The adjusted hazard ratio was 2.49 (95% confidence interval, 1.26–4.94) for mortality, 3.14 (2.25–4.38) for myasthenic crisis, 1.54 (1.15–2.06) for hospitalization, 2.69 (1.74–4.15) for pneumonia/sepsis, and 1.81 (1.28–2.56) for ED visits for rMG versus non-rMG. The immunosuppressant prescriptions were more prevalent in patients with rMG, while the difference was more remarkable before rMG onset rather than after rMG onset. Conclusion Despite the severe prognosis of rMG, the strategies for pharmacotherapeutic regimens were similar in those two groups, suggesting that intensive monitoring and introduction of timely treatment options in the early phase of MG are required.

This study sought to describe and to evaluate the characteristics of the Health Screening Records Database (HSRD) of the Korea Association of Health Promotion as a data source for epidemiologic studies. The HSRD was compared to a National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) database for 2015. Common variables between the databases were selected, and sex-based analyses were conducted. The HSRD showed statistical concordance when NHIS-HEALS estimates fell within the HSRD estimate's 95% confidence interval. The HSRD and NHIS-HEALS included 946461 and 111690 participants in health screening programs, respectively. Compared to the NHIS-HEALS, the HSRD had more female (55.2% vs. 42.6%) but fewer older adult participants (34.4% vs. 51.2%). Virtually all variables had clinical concordance, with some having statistical concordance as well, among both general and life-transition program participants. The HSRD comprised more clinical information over a wider age range in contrast to the NHIS-HEALS, while showing clinical concordance. Providing more comprehensive clinical data, the HSRD may serve as an alternative resource for epidemiologic studies.
Adult ; Cohort Studies ; Epidemiologic Studies ; Female ; Health Promotion ; Humans ; Information Storage and Retrieval ; Korea ; Mass Screening ; National Health Programs ; Observational Study ; Physical Examination

This was a cross-sectional study using the data collected from a nationwide survey between November and December 2022 to explore factors associated with hesitancy towards coronavirus disease 2019 (COVID-19) vaccination for children. Among 3,011 participants with child aged 5–11 years, 82.5% demonstrated hesitancy towards vaccinating their child. This was more common among mothers (odds ratio 1.84 [95% confidence interval 1.46–2.31]), those residing outside metropolitan area (urban: 2.46 [1.89–3.20]; rural: 2.87 [2.09–3.93]) or with history of COVID-19 diagnosis (2.22 [1.78–2.76]). Parents were also hesitant if their child recently had COVID-19 (3.41 [2.67–4.37]). Conversely, they were less likely to be hesitant if they had three or more children (0.66 [0.46–0.94]) or if their child has underlying medical condition(s) (0.54 [0.41–0.71]). Our findings highlight high prevalence of parental hesitancy towards COVID-19 vaccination for children, and call for targeted outreach efforts from the stakeholders to facilitate the vaccine uptake in this pediatric population.

Background: Although coronavirus disease 2019 (COVID-19) vaccines have been distributed worldwide under emergency use authorization, the real-world safety profiles of mRNA vaccines still need to be clearly defined. We aimed to identify the overall incidence and factors associated with adverse events (AEs) following mRNA COVID-19 vaccination. Methods: We conducted web-based survey from December 2 to 10 in 2021 with a 2,849 nationwide sampled panel. Study participants were individuals who had elapsed at least twoweeks after completing two dosing schedules of COVID-19 vaccination aged between 18–49 years. We weighted the participants to represent the Korean population. The outcome was the overall incidence of AEs following mRNA COVID-19 vaccination and associated factors.We estimated the weighted odds ratios (ORs) using multivariable logistic regression models to identify the factors associated with AEs. Results: Of the 2,849 participants (median [interquartile range] age, 35 [27–42] years; 51.6% male), 90.8% (n = 2,582) for the first dose and 88.7% (n = 2,849) for the second dose reported AEs, and 3.3% and 4.3% reported severe AEs, respectively. Occurrence of AEs was more prevalent in mRNA-1273 (OR, 2.06; 95% confidence interval [CI], 1.59–2.67 vs. BNT162b2), female sex (1.88; 1.52–2.32), and those with dermatologic diseases (2.51; 1.32–4.77). History of serious allergic reactions (1.96; 1.06–3.64) and anticoagulant medication use (4.72; 1.92–11.6) were associated with severe AEs. Conclusion Approximately 90% of participants reported AEs following mRNA COVID-19 vaccination. Substantial factors, including vaccine type (mRNA-1273), female sex, and dermatologic diseases were associated with AEs. Our findings could aid policymakers in establishing vaccination strategies tailored to those potentially susceptible to AEs.

OBJECTIVES: This study investigated the reporting rates of adverse events following immunization (AEFIs) to the spontaneous reporting system (SRS) and its predictors among individuals with AEFIs after coronavirus disease 2019 (COVID-19) vaccination. METHODS: A cross-sectional, web-based survey was conducted from December 2, 2021 to December 20, 2021, recruiting participants >14 days after completion of a primary COVID-19 vaccination series. Reporting rates were calculated by dividing the number of participants who reported AEFIs to the SRS by the total number of participants who experienced AEFIs. We estimated adjusted odds ratios (aORs) using multivariate logistic regression to determine factors associated with spontaneous AEFIs reporting. RESULTS: Among 2,993 participants, 90.9% and 88.7% experienced AEFIs after the first and second vaccine doses, respectively (reporting rates, 11.6 and 12.7%). Furthermore, 3.3% and 4.2% suffered moderate to severe AEFIs, respectively (reporting rates, 50.5 and 50.0%). Spontaneous reporting was more prevalent in female (aOR, 1.54; 95% confidence interval [CI], 1.31 to 1.81); those with moderate to severe AEFIs (aOR, 5.47; 95% CI, 4.45 to 6.73), comorbidities (aOR, 1.31; 95% CI, 1.09 to 1.57), a history of severe allergic reactions (aOR, 2.02; 95% CI, 1.47 to 2.77); and those who had received mRNA-1273 (aOR, 1.25; 95% CI, 1.05 to 1.49) or ChAdOx1 (aOR, 1.62; 95% CI, 1.15 to 2.30) vaccines versus BNT162b2. Reporting was less likely in older individuals (aOR, 0.98; 95% CI, 0.98 to 0.99 per 1-year age increment). CONCLUSIONS Spontaneous reporting of AEFIs after COVID-19 vaccination was associated with younger age, female sex, moderate to severe AEFIs, comorbidities, history of allergic reactions, and vaccine type. AEFIs under-reporting should be considered when delivering information to the community and in public health decision-making.

OBJECTIVE: To gather inputs from clinical experts on selecting and prioritizing research topics, to address unmet vaccine safety needs. METHODS: A questionnaire containing 15 vaccine safety assessment research proposals was sent to 28 vaccine experts chosen from various domestic medical association boards, and the rationale for each of the proposals was provided by presenting the following information: 1) a brief summary of the clinical safety studies on the vaccine, conducted by the Clinical Immunization Safety Assessment (CISA) project group, supervised by the United States Center for Disease Control (U.S. CDC), and 2) a summary of recently published studies that address vaccine safety issues. The experts were instructed to select and rank 5 topics in the order of preference, and the preference score for each proposed topic was calculated by assigning points on a scale of 1 to 5. RESULTS: All 28 experts responded to the questionnaire, and the following topics were selected according to their calculated preference scores: 1) Human papillomavirus vaccine safety profile in the Korean female adolescents; 2) A signal detection of adverse events following Influenza vaccination: comparison between the US and South Korea; 3) Incidence of anaphylaxis following National Immunization Program vaccines between 2008 and 2017; 4) Safety of quadrivalent influenza vaccines compared to trivalent influenza vaccines; and 5) Pneumococcal vaccine safety profile in the general population. CONCLUSION: Five research topics addressing vaccine safety were selected, for which well-constructed research protocols need to be promptly developed to address current unmet vaccine safety needs in South Korea.
Adolescent ; Anaphylaxis ; Centers for Disease Control and Prevention (U.S.) ; Decision Making ; Humans ; Immunization ; Immunization Programs ; Incidence ; Influenza Vaccines ; Influenza, Human ; Korea ; Research Design ; United States ; Vaccination ; Vaccines