Global health security threats in the post-coronavirus disease 2019 era include dense urban populations, increased human–animal proximity, migration driven by political or economic instability, climate change, humanitarian crises, antimicrobial resistance (AMR), and the misuse of biological research—including the accidental or intentional release of high-risk pathogens. The foundational preparation for these threats is to establish a robust, resilient public health system based on universal health coverage. The World Health Organization’s International Health Regulations must continue to promote global solidarity by maintaining core capacities such as surveillance, national laboratories, and epidemiological investigations of emerging infectious diseases, with timely reporting and information sharing within the global health security community. A One Health approach is essential for addressing AMR. Infection prevention and control must be enhanced to reduce healthcare-associated infections in medical facilities. Additionally, regulations concerning biosafety and biosecurity should address dual-use research of concern as well as the accidental or intentional release of highrisk pathogens from laboratories. Global health security is a collective responsibility because these threats know no borders and require coordinated action.

<b>Objectives</b><br/>This study aimed to investigate the combined effects of individual, household, and community-level factors on coronavirus disease 2019 (COVID-19) vaccination intention using a multilevel analysis. Methods: This cross-sectional study analyzed raw data from the 2021 Korea Community Health Survey and regional statistics from 255 health centers, with a final sample of 229,216 individuals. Multilevel analysis was conducted, focusing on individual, household, and community-level factors. Individual-level factors included demographics, health status, and COVID-19 concerns; household-level factors included income and marital status; and community-level factors included city type and vaccination rates. Results: At the individual level, significant differences were observed across all variables. At the household level, higher vaccination intention was associated with households of 4 or more members and a monthly income of 4 million Korean won or more. At the community level, higher flu vaccination rates, greater concern about COVID-19 infection, and higher COVID-19 vaccination rates were linked to increased vaccination intention. Conclusion: This study highlights that COVID-19 vaccination intention is influenced by factors at the individual, household, and community levels. Vaccination strategies that integrate household and community-level approaches may be more effective. Policymakers should consider both individual and social health factors when designing vaccination policies.

<b>Objectives</b><br/>Mortality statistics during the coronavirus disease 2019 (COVID-19) pandemic are crucial for the allocation of medical care resources and public health decision-making. This study was initiated to investigate the excess mortality among older adults during the pandemic. Our research focuses on 2 primary areas. First, we analyzed the cumulative excess mortality across all age groups to assess the global impact and specifically examined the top 20 countries with the highest mortality rates during the pandemic. Second, we explored excess deaths among older adults by categorizing data from the years 2020 and 2021 into age groups: 65–74, 75–84, and above 85. <br/><b>Methods</b><br/>We analyzed data from the top 20 countries with the highest mortality rates globally, focusing on 3 components: all-cause mortality means, expected deaths mean, and excess deaths mean for both older men and women. <br/><b>Results</b><br/>Although excess mortality is higher among older men and women across all 3 age groups (65–74, 75–84, and >85), the highest mean excess mortality was observed in women over the age of 85. <br/><b>Conclusion</b><br/>The results indicate that the severe acute respiratory syndrome coronavirus 2 virus had a disproportionately intense impact on older women. We developed 2 types of statistical models using the data: a binomial distribution model and a correlation coefficient model, both considering the mean excess deaths in older men and women across these 3 age groups. Estimating the excess mortality among older adults will aid in the formulation of healthcare policies for this demographic.

<b>Objectives</b><br/>We analyzed the demographic and clinical characteristics of patients diagnosed with coronavirus disease 2019 (COVID-19), focusing specifically on severe/critical cases, and assessed the trends and rates of severity and fatality among these patients in the Republic of Korea. <br/><b>Methods</b><br/>Clinical data on patients with COVID-19 from January 20, 2020 to August 30, 2023 were collected from the Korea Disease Control and Prevention Agency’s database. We identified patients who progressed to severe/critical conditions and analyzed their demographic and clinical profiles. Severity and fatality rates were calculated and compared annually to track the disease progression over time. <br/><b>Results</b><br/>During the surveillance period, 34,572,554 COVID-19 cases were confirmed, among whom 38,112 (0.11%) progressed to severe/critical conditions. Most severe/critical cases occurred in individuals aged ≥60 years, with a notable increase in patients aged ≥80 years from 2022. The overall severity rate was 0.19%, with a fatality rate of 0.10%. However, the severity of cases gradually diminished during the study period. In 2022, the severity and fatality rates decreased to 0.14% and 0.09%, respectively. In 2023, while the severity rate remained stable at 0.15%, the fatality rate further decreased to 0.06%. Notably, throughout the study period, individuals aged ≥80 years had a significantly higher severity rate (2.44%), with a fatality rate of 1.75%. <br/><b>Conclusion</b><br/>These findings underscore the importance of prioritizing protection and management strategies for older adults and high-risk groups to mitigate the impact of COVID-19. Continued surveillance and analysis are essential to effectively control COVID-19 and minimize its burden on public health.

<b>Objectives</b><br/>This study aimed to summarize the results of coronavirus disease 2019 (COVID-19) risk assessments and to examine the associations between risk levels and various indicators, including COVID-19 incidence, risk perception, community mobility, and government policy. <br/><b>Methods</b><br/>The results of the risk assessment and the indicators utilized were summarized. From November 2021 to May 2022, the COVID-19 risk level was evaluated on a weekly basis, and its correlation with these indicators was analyzed. Data were obtained from press releases by the Korea Disease Control and Prevention Agency, regular surveys conducted by Hankook Research, and information available on the Google and Oxford websites. <br/><b>Results</b><br/>Weekly risk assessments were conducted for 30 weeks, using different indices depending on the phases. Correlation analysis revealed the strongest positive correlation between risk level and risk perception (r=0.841). The risk level from “1-week lead” demonstrated a strong positive correlation with the time-varying reproduction number (Rt). Similarly, the risk level from “week lagged value” showed a strong positive correlation with the number of severe cases in the hospital. <br/><b>Conclusion</b><br/>At the time of risk assessment, the Rt precedes the risk level, while severe cases in hospitals follow. Therefore, the assessed risk level functioned as an early warning system. Risk perception demonstrated the strongest correlation with the risk level, suggesting consistency throughout the assessment period. Contextual indicators (e.g., risk perception) that consider time lags and implementation scales, could improve the evaluation of future risk assessment results, particularly when there are challenges in reflecting specific situations in coordinated emergency response.

<b>Objectives</b><br/>The aim of this study was to disseminate information about the safety of bivalent coronavirus disease 2019 (COVID-19) mRNA booster vaccines administered to adults in the Republic of Korea. <br/><b>Methods</b><br/>Two databases were used to assess the safety of COVID-19 booster doses of Pfizer BA.1, Pfizer BA.4/5, Moderna BA.1, and Moderna BA.4/5 vaccines for adults aged 18 years and older. Adverse events (AEs) were analyzed using data reported to the web-based COVID-19 vaccination management system (CVMS) and a self-reported text-message survey. <br/><b>Results</b><br/>Between October 11, 2022 and March 30, 2023, the CVMS received reports of 2,369 (93.7%) non-serious AEs from vaccinated adults, along with 158 (6.3%) serious AEs, which included 5 cases of anaphylaxis and 33 deaths. From October 11, 2022 to January 27, 2023, 40,022 people aged 18 and older responded to a survey conducted via text message. The booster doses were associated with fewer local and systemic AEs compared to the original vaccines. After receiving the bivalent vaccine, the most commonly reported AEs were pain at the injection site, headache, fatigue, and myalgia. <br/><b>Conclusion</b><br/>Overall, bivalent vaccines exhibited fewer AEs compared to the original vaccines. The majority of AEs were non-serious, and serious AEs were rare among adults aged 18 years and older following vaccination with the Pfizer and Moderna bivalent vaccines.

<b>Objectives</b><br/>This study aimed to comprehensively outline the methodological approaches used in published research comparing the vaccine effectiveness (VE) of coronavirus disease 2019 (COVID-19) vaccines. <br/><b>Methods</b><br/>A systematic search was conducted on June 13, 2024, to identify comparative studies evaluating the effectiveness of mRNA versus non-mRNA and monovalent versus bivalent COVID-19 vaccines. We screened titles, abstracts, and full texts, collecting data on publication year, country, sample size, study population composition, study design, VE estimates, outcomes, and covariates. Studies that reported relative VE (rVE) were analyzed separately from those that did not. <br/><b>Results</b><br/>We identified 25 articles comparing rVE between mRNA and non-mRNA COVID-19 vaccines, as well as between monovalent and bivalent formulations. Among the studies assessing VE by vaccine type, 126 did not provide rVE estimates. Comparative VE studies frequently employed retrospective cohort designs. Among the definitions of rVE used, the most common were hazard ratio and absolute VE, calculated as (1−odds ratio)×100. Studies were most frequently conducted in the United Kingdom and the United States, and the most common outcome was infection. Most targeted the general population and assessed the VE of mRNA vaccines using the AstraZeneca vaccine as a reference. A small proportion, 7.3% (n=11), did not adjust for any variables. Only 3 studies (2.0%) adjusted for all core confounding variables recommended by the World Health Organization. <br/><b>Conclusion</b><br/>Few comparative studies of COVID-19 vaccines have incorporated rVE methodologies. Reporting rVE and employing a consistent set of covariates can broaden our understanding of COVID-19 vaccines.

<b>Objectives</b><br/>Public health workers have been at the forefront of treating patients with coronavirus disease 2019 (COVID-19) and managing the pandemic. The redeployment of this workforce has limited or interrupted other public health services, including testing for human immunodeficiency virus (HIV). This study aims to examine the impact of COVID-19 on HIV testing and diagnosis in the Republic of Korea from 2016 to 2021, comparing data before and after the onset of COVID-19. <br/><b>Methods</b><br/>Annual HIV testing data were collected from each institution through direct communication or from open-source databases. The annual number of new HIV cases was obtained from the official report of the Korea Disease Control and Prevention Agency. Data on healthcare visits for HIV diagnosis or treatment were extracted from the open-source database of the National Insurance Health Service of Korea. Interrupted time series regression was conducted, stratified by institution type. <br/><b>Results</b><br/>In 2020, HIV tests, diagnoses, and visits decreased. Notably, public health centers experienced a substantial reduction in 2020−2021 compared to previous years. The annual percentage change in HIV tests was −53.0%, while for HIV diagnoses, it was −31.6%. The decrease in visits for HIV was also most pronounced for public facilities: −33.3% in 2020 and −45.6% in 2021 relative to 2019. <br/><b>Conclusion</b><br/>The numbers of tests, diagnoses, and healthcare visits for HIV at public health centers in the Republic of Korea substantially decreased in 2020 and 2021. The impacts of these changes on the early diagnosis and treatment of HIV necessitate further monitoring.

<b>Objectives</b><br/>No study has yet analyzed risk factors to determine whether students with confirmed coronavirus disease 2019 (COVID-19) infections may affect students at neighboring schools. Therefore, this study aimed to determine risk factors for COVID-19 transmission among schools within a community in the Republic of Korea. <br/><b>Methods</b><br/>An epidemiological investigation was conducted among 696 students and school staff members at 3 schools where COVID-19 clusters began on October 15, 2021. Interviews, visit history surveys, a facility risk assessment, and closed-circuit television were used to identify risk factors. The statistical significance of risk factors was also evaluated. <br/><b>Results</b><br/>We confirmed 129 cases (18.5%) among the individuals exposed to COVID-19 at the 3 schools, many of whom had a history of visiting the same multi-use facilities. The odds ratio of having visited multi-use facilities such as karaoke rooms was 1.90 (95% confidence interval, 1.03–3.50); the number of visits to a karaoke room and the visit durations were significantly higher among confirmed cases than non-confirmed cases (p=0.02 and p=0.03, respectively). <br/><b>Conclusion</b><br/>Having a history of visiting karaoke rooms often and spending a long time there were risk factors for COVID-19 infection and inter-school transmission. Thus, it is necessary to investigate the status of multi-use facilities frequently visited by adolescents and consider incorporating them into the scope of school quarantine to prevent infectious diseases at schools in a community.

<b>Objectives</b><br/>This study analyzed the safety of coronavirus disease 2019 (COVID-19) bivalent and monovalent booster vaccines, including the frequency of adverse events (AEs) such as myocarditis and pericarditis, in adolescents aged 12 to 17 years in the Republic of Korea. We aimed to share the safety profile of the COVID-19 bivalent vaccine booster doses. <br/><b>Methods</b><br/>We analyzed the frequencies of AEs reported to the COVID-19 vaccination management system (CVMS) or self-reported through the text message survey (TMS). Diagnostic eligibility and causality with vaccines were compared using odds ratios (ORs) by vaccine type, and incidence rates per 100,000 person-days were calculated for confirmed cases of myocarditis and pericarditis following monovalent and bivalent booster doses. <br/><b>Results</b><br/>In the CVMS, the AE reporting rate (per 100,000 doses) was lower after the bivalent booster (66.5) than after the monovalent booster (264.6). Among the AEs reported for both monovalent and bivalent vaccines 98.3% were non-serious and 1.7% were serious. According to the TMS, both local and systemic AEs were reported less frequently after the bivalent vaccination than after the monovalent vaccination in adolescents aged 12 to 17 years (p<0.001). The incidence rates per 100,000 person-days for confirmed myocarditis/pericarditis following monovalent and bivalent booster doses were 0.03 and 0.05, respectively; this difference was not statistically significant (OR, 1.797; 95% confidence interval, 0.210–15.386). <br/><b>Conclusion</b><br/>AEs in 12- to 17-year-olds following the bivalent booster were less frequent than those following the monovalent booster in the Republic of Korea, and no major safety issues were identified. However, the reporting rates for AEs were low.

<b>Objectives</b><br/>Post-coronavirus disease 2019 (COVID-19) symptoms were widely reported. However, data on post-COVID-19 conditions following infection with the Omicron variant remained scarce. This prospective study was conducted to understand the prevalence, patterns, and duration of symptoms in patients who had recovered from COVID-19. Methods: A prospective study was conducted across 11 districts of Delhi, India, among individuals who had recovered from COVID-19. Study participants were enrolled, and then returned for post-recovery follow-up at 3 months and 6 months interval. Results: The mean age of study participants was 42.07 years, with a standard deviation of 14.89 years. The majority of the participants (79.7%) reported experiencing post-COVID-19 symptoms. The most common symptoms included joint pain (36.0%), persistent dry cough (35.7%), anxiety (28.4%), and shortness of breath (27.1%). Other symptoms were persistent fatigue (21.6%), persistent headache (20.0%), forgetfulness (19.7%), and limb weakness (18.6%). The longest duration of symptom was observed to be anxiety (138.75±54.14 days), followed by fatigue (137.57±48.33 days), shortness of breath (131.89±60.21 days), and joint pain/swelling (131.59±58.76 days). At the first follow-up visit, 2.2% of participants presented with abnormal electrocardiogram readings, but no abnormalities were noticed during the second follow-up. Additionally, 4.06% of participants exhibited abnormal chest X-ray findings at the first followup, which decreased to 2.16% by the second visit. Conclusion: The most frequently reported post-COVID-19 symptoms were joint pain, dry cough, anxiety and shortness of breath. These clinical symptoms persisted for up to 6 months, with evidence of multi-system involvement. Consequently, findings highlighted the need for long-term follow-up during the post-COVID-19 period.

The COVID-19 Vaccine Safety Research Committee (CoVaSC) was established in November 2021 to address the growing need for independent, in-depth scientific evidence on adverse events (AEs) following coronavirus disease 2019 (COVID-19) vaccination. This initiative was requested by the Korea Disease Control and Prevention Agency and led by the National Academy of Medicine of Korea. In September 2022, the COVID-19 Vaccine Safety Research Center was established, strengthening CoVaSC’s initiatives. The center has conducted various studies on the safety of COVID-19 vaccines. During CoVaSC’s second research year, from September 29, 2022 to July 19, 2023, the center was restructured into 4 departments: Epidemiological Research, Clinical Research, Communication & Education, and International Cooperation & Policy Research. Its main activities include (1) managing CoVaSC and the COVID-19 Vaccine Safety Research Center, (2) surveying domestic and international trends in AE causality investigation, (3) assessing AEs following COVID-19 vaccination, (4) fostering international collaboration and policy research, and (5) organizing regular fora and training sessions for the public and clinicians. Causality assessments have been conducted for 27 diseases, and independent research has been conducted after organizing ad hoc committees comprising both epidemiologists and clinical experts on each AE of interest. The research process included protocol development, data analysis, interpretation of results, and causality assessment. These research outcomes have been shared transparently with the public and healthcare experts through various fora. The COVID-19 Vaccine Safety Research Center plans to continue strengthening and expanding its research activities to provide reliable, high-quality safety information to the public.

This systematic review evaluated psychiatric adverse events (AEs) following vaccination against coronavirus disease 2019 (COVID-19). We included studies that reported or investigated psychiatric AEs in individuals who had received an approved COVID-19 vaccine in the Republic of Korea. Systematic electronic searches of Ovid-Medline, Embase, CENTRAL, and KoreaMed databases were conducted on March 22, 2023. Risk of bias was assessed using the Risk of Bias Assessment Tool for Non-randomized Studies 2.0. The study protocol was registered in the International Prospective Register of Systematic Reviews (CRD42023449422). Of the 301 articles initially selected, 7 were included in the final analysis. All studies reported on sleep disturbances, and 2 highlighted anxiety-related AEs. Sleep disorders like insomnia and narcolepsy were the most prevalent AEs, while depression was not reported. Our review suggests that these AEs may have been influenced by biological mechanisms as well as the broader psychosocial context of the COVID-19 pandemic. Although this study had limitations, such as a primary focus on the BNT162b2 vaccine and an observational study design, it offered a systematic, multi-vaccine analysis that fills a critical gap in the existing literature. This review underscores the need for continued surveillance of psychiatric AEs and guides future research to investigate underlying mechanisms, identify risk factors, and inform clinical management.

<b>Objectives</b><br/>This study was conducted to assess the efficacy of nirmatrelvir/ritonavir treatment in patients with coronavirus disease 2019 (COVID-19), particularly those aged 60 years and older. Using real-world data, the period during which the BN.1 Omicron variant was dominant was compared to the period dominated by the BA.5 variant. Methods: In this retrospective cohort study, data were collected regarding 2,665,281 patients infected with severe acute respiratory syndrome coronavirus 2 between July 24, 2022, and March 31, 2023. Propensity score matching was utilized to match patients who received nirmatrelvir/ ritonavir in a 1:4 ratio between BN.1 and BA.5 variant groups. Multivariable logistic regression analysis was employed to assess the effects of nirmatrelvir/ritonavir within these groups. Results: Compared to the prior period, the efficacy of nirmatrelvir/ritonavir did not significantly differ during the interval of Omicron BN.1 variant dominance in the Republic of Korea. Among patients treated with nirmatrelvir/ritonavir, a significantly lower risk of mortality was observed in the BN.1 group (odds ratio [OR], 0.698; 95% confidence interval [CI], 0.557–0.875) compared to the BA.5 group. However, this treatment did not significantly reduce the risk of severe or critical illness, including death, for those in the BN.1 group (OR, 0.856; 95% CI, 0.728–1.007). Conclusion: Nirmatrelvir/ritonavir has maintained its effectiveness against COVID-19, even with the emergence of the BN.1 Omicron subvariant. Consequently, we strongly recommend the administration of nirmatrelvir/ritonavir to patients exhibiting COVID-19-related symptoms, irrespective of the dominant Omicron variant or their vaccination status, to mitigate disease severity and decrease the risk of mortality.

<b>Objectives</b><br/>This study investigated the characteristics of coronavirus disease 2019 (COVID-19) among individuals with disabilities on a nationwide scale in the Republic of Korea, as limited research has examined this population. Methods: Between January 1 and November 30, 2021, a total of 5,687 confirmed COVID-19 cases among individuals with disabilities were reported through the Korea Disease Control and Prevention Agency’s COVID-19 web reporting system. Follow-up continued until December 24, and demographic, epidemiological, and clinical characteristics were analyzed. Results: Individuals with disabilities represented approximately 1.5% of confirmed cases, with a mean age of 58.1 years. Most resided in or near metropolitan areas (86.6%) and were male (60.6%). Frequent sources of infection included home (33.4%) and contact with confirmed cases (40.7%). Many individuals (75.9%) had underlying conditions, and 7.7% of cases were severe. People with disabilities showed significantly elevated risk of severe infection (adjusted odds ratio [aOR], 1.63; 95% confidence interval [CI], 1.47–1.81) and mortality (aOR, 1.65; 95% CI, 1.43–1.91). Vaccination against COVID-19 was associated with significantly lower risk of severe infection (aORs for the first, second, and third doses: 0.60 [95% CI, 0.42–0.85], 0.28 [95% CI, 0.22–0.35], and 0.16 [95% CI, 0.05–0.51], respectively) and death (adjusted hazard ratios for the first and second doses: 0.57 [95% CI, 0.35–0.93] and 0.30 [95% CI, 0.23–0.40], respectively). Conclusion: Individuals with disabilities showed higher risk of severe infection and mortality from COVID-19. Consequently, it is critical to strengthen COVID-19 vaccination initiatives and provide socioeconomic assistance for this vulnerable population.