The COVID-19 Vaccine Safety Research Center: a cornerstone for strengthening safety evidence for COVID-19 vaccination in the Republic of Korea.

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.

Secondary Cancer after Androgen Deprivation Therapy in Prostate Cancer: A Nationwide Study.

PURPOSE: Androgen signaling is associated with various secondary cancer, which could be promising for potential treatment using androgen deprivation therapy (ADT). This study investigated whether ADT use was associated with secondary cancers other than prostate cancer in a nationwide population-based cohort. MATERIALS AND METHODS: A total, 278,434 men with newly diagnosed prostate cancer between January 1, 2002 and December 31, 2017 were identified. After applying the exclusion criteria, 170,416 men were enrolled. The study cohort was divided into ADT and non-ADT groups by individual matching followed by propensity score matching (PSM). Study outcomes were incidence of all male cancers. Cox proportional hazard regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of events. RESULTS: During a median follow-up of 4.5 years, a total of 11,059 deaths (6,329 in the ADT group and 4,730 in the non-ADT group) after PSM were found. After PSM, the overall all-cause of secondary cancer incidence risk of the ADT group was higher than that of the non-ADT group (HR: 1.312, 95% CI: 1.23-1.36; adjusted HR: 1.344, 95% CI: 1.29-1.40). The ADT group showed higher risk of overall brain and other central nervous system (CNS) cancer-specific incidence than the non-ADT group (adjusted HR: 1.648, 95% CI: 1.21-2.24). The ADT group showed lower risks of overall cancer-specific incidence for stomach, colon/rectum, liver/inflammatory bowel disease (IBD), gall bladder/extrahepatic bile duct, lung, bladder, and kidney cancers than the non-ADT group. When the duration of ADT was more than 2 years of ADT, the ADT group showed higher risk of cancer-specific incidence for brain and other CNS cancers but lower risk of cancer-specific incidence for liver/IBD and lung cancers than the non-ADT group. CONCLUSIONS: This study demonstrates that ADT could affect cancer-specific incidence for various cancers.

Inverse association with COVID-19 vaccination status of the incidence of pneumonia after SARS-CoV-2 infection: A nationwide retrospective cohort study.

BACKGROUND: Although one of the characteristics of COVID-19 is accompanied by acute pneumonia immediately after infection, large-scale cohort studies focused on this issue are lacking. In addition, there is interest in how COVID-19 vaccinations reduce the incidence of acute pneumonia for people infected with different strains of SARS-CoV-2. Thus, we assess the short-term incidence of pneumonia after COVID-19 with the vaccination and SARS-CoV-2 variants. METHODS: As data for 2136,751 COVID-19 patients between January 01, 2020 and February 28, 2022 was collected, they were observed for one month from the day of infection. Patients in retrospective cohort study were classified according to doses of the received vaccine and the epidemic phase when SARS-CoV-2 variants prevailed. Multivariable logistic regression analysis calculated adjusted odds ratios (aOR) and 95% confidence intervals (CIs) for the pneumonia risk. RESULTS: In B.1.1.7-B.1.351, B.1.617.2, and B.1.617.2 variants, the aORs (95% CIs; p-value) for incidence of pneumonia were 0.93 (0.89-0.98; <0.001), 0.74 (0.70-0.78; <0.001), and 0.04 (0.038-0.043; <0.001), respectively, compared to the original strain. More than 80% of patients have received the second and more doses of the vaccine (average age=44.67 years). The aORs (95% CIs; p-value) for pneumonia were 0.61 (0.58-0.64; <0.001), 0.39 (0.38-0.40; <0.001), and 0.18 (0.166-0.184; <0.001) in patients who received the first (N = 68,216), second (N = 898,838), and ≥ third doses (N = 836,173), respectively, compared to unvaccinated patients. According to the received vaccine (second dose of mRNA or viral vector), those who received BNT162b2 and mRNA-1273 (N = 787,980) had lower risk of pneumonia, compared to that in those who received h ChAdOx1 nCov-19 and AD26. COV2-S (N = 89,024). CONCLUSIONS: Our findings suggest that the second and ≥ third doses (61% and 82% of risk aversion effect increased, respectively) of the COVID-19 vaccine can prevent the COVID-19-related pneumonia, regardless of the variants.

Comparison of Participation in Strength Activity Among People With and Without Disabilities: 2013-2017 Behavioral Risk Factor Surveillance System.

BACKGROUND: The current physical activity guidelines recommend engagement in strength activities at least 2 days per week. Currently, there is a lack of literature examining strength activities among people with disabilities. The purpose of this study is to estimate and compare the prevalence of engagement in strength activities and adherence to strength activity guidelines among adults with and without disabilities in the United States. METHODS: A total of 1,005,644 adults (18-80 y old) with and without disabilities from the 2013 to 2017 Behavioral Risk Factor Surveillance System were included in this secondary data analysis. Descriptive analyses were performed to describe the prevalence of strength activity behaviors of adults with and without disabilities. Logistic and Poisson regression models were performed to evaluate the relative contribution of disability status on strength activity behaviors. RESULTS: A higher proportion of participants without disabilities (46.42%, 95% CI, 46.18-46.65) reported engaging in strength activities compared with participants with disabilities (30.68%, 95% CI, 30.29-31.08; P < .01). Participants with disabilities were less likely to engage in strength activities (odds ratio = 0.51, 95% CI, 0.50-0.52; adjusted odds ratio = 0.75, 95% CI, 0.73-0.77) and meet strength activity guidelines (odds ratio = 0.56, 95% CI, 0.54-0.57; adjusted odds ratio = 0.75, 95% CI, 0.73-0.77) than participants without disabilities. CONCLUSION: Experiencing a disability is associated with lower engagement in strength activities; thus, it is important to identify effective and efficient approaches to promoting strength activities among people with disabilities.

Force-fluorescence setup for observing protein-DNA interactions under load.

This chapter explores advanced single-molecule techniques for studying protein-DNA interactions, particularly focusing on Replication Protein A (RPA) using a force-fluorescence setup. It combines magnetic tweezers (MT) with total internal reflection fluorescence (TIRF) microscopy, enabling detailed observation of DNA behavior under mechanical stress. The chapter details the use of DNA hairpins and bare DNA to examine RPA's binding dynamics and its influence on DNA's mechanical properties. This approach provides deeper insights into RPA's role in DNA replication, repair, and recombination, highlighting its significance in maintaining genomic stability.

Vaccination and the risk of post-acute sequelae after COVID-19 in the Omicron-predominant period.

OBJECTIVES: To assess the association of primary and third doses of vaccination with the risk of post-acute sequelae of COVID-19. METHODS: This retrospective cohort study utilized a combined database of nationwide health care claims data, COVID-19 patient registry, and vaccination records from South Korea. Individuals diagnosed with COVID-19 in the Omicron variant-dominant period of January-March 2022 were tracked for 30-120 days post-infection. The exposure of interest was the receipt of primary and third doses of the SARS-CoV-2 vaccine. The occurrence of 26 specific conditions in eight domains was compared using Cox regression with inverse probability of treatment weighting. RESULTS: This study included 394 773 unvaccinated individuals and 7 604 081 individuals receiving ≥2 doses of vaccine. Compared with unvaccinated individuals, vaccination with at least two doses was associated with a reduced risk (adjusted hazard ratio; 95% CI) of several conditions, including ischaemic heart disease (0.73; 0.57-0.94), heart failure (0.55; 0.48-0.63), cardiac dysrhythmia (0.72; 0.61-0.85), cardiac arrest (0.41; 0.33-0.51), pulmonary embolism (0.66; 0.52-0.84), venous thromboembolism (0.54; 0.44-0.66), acute renal failure (0.56; 0.46-0.67), new dialysis (0.45; 0.34-0.59), chronic obstructive pulmonary disease (0.74; 0.65-0.84), acute pancreatitis (0.64; 0.51-0.80), and diabetes (0.82; 0.71-0.95). The risks of heart failure, cardiac dysrhythmias, cardiac arrest, pulmonary embolism, and new dialysis were lower in those who were vaccinated with three doses compared with those who were vaccinated with two doses. DISCUSSION: Vaccination was associated with a decreased risk of post-acute sequelae of COVID-19, suggesting its potential role in mitigating the indirect impacts of COVID-19.

Prevalence and Burden of Human Adenovirus-Associated Acute Respiratory Illness in the Republic of Korea Military, 2013 to 2022.

BACKGROUND: Human adenovirus (HAdV) is a common cause of acute respiratory disease (ARD) and has raised significant concerns within the Korean military. Here, we conducted a comprehensive epidemiological analysis of HAdV-associated ARD by evaluating its prevalence, clinical outcomes, and prognosis. METHODS: We reviewed data from multiple sources, including the New Defense Medical Information System, Defense Medical Statistical Information System, Ministry of National Defense, Army Headquarters, Navy Headquarters, Air Force Headquarters, and Armed Forces Medical Command. We analyzed data of patients who underwent polymerase chain reaction (PCR) testing for respiratory viruses between January 2013 and July 2022 in all 14 Korean military hospitals. The analysis included the PCR test results, demographic characteristics, health care utilization, and prognosis including types of treatments received, incidence of pneumonia, and mortality. RESULTS: Among the 23,830 individuals who underwent PCR testing at Korean military hospitals, 44.78% (10,670 cases) tested positive for respiratory viruses. Across all military types and ranks, HAdV was the most prevalent virus, with a total of 8,580 patients diagnosed, among HAdV, influenza virus, human metapneumovirus, human parainfluenza virus, and human respiratory syncytial virus. HAdV-infected patients exhibited higher rates of healthcare use compared to non-HAdV-infected patients, including a greater number of emergency visits (1.04 vs. 1.02) and outpatient visits (1.31 vs. 1.27), longer hospitalizations (8.14 days vs. 6.84 days), and extended stays in the intensive care unit (5.21 days vs. 3.38 days). Furthermore, HAdV-infected patients had a higher proportion of pneumonia cases (65.79% vs. 48.33%) and greater likelihood of receiving advanced treatments such as high flow nasal cannula or continuous renal replacement therapy. CONCLUSION: Our findings indicate that HAdV posed a significant public health concern within the Korean military prior to the coronavirus disease 2019 (COVID-19) pandemic. Given the potential for a resurgence of outbreaks in the post-COVID-19 era, proactive measures, such as education, environmental improvements, and the development of HAdV vaccines, are crucial for effectively preventing future outbreaks.

Comparative safety analysis of mRNA and adenoviral vector COVID-19 vaccines: a nationwide cohort study using an emulated target trial approach.

OBJECTIVE: This nationwide cohort study compared the incidence of adverse events of special interest (AESIs) between adenoviral vector-based (ChAdOx1) and mRNA-based (BNT162b2 or mRNA-1273) coronavirus disease 2019 (COVID-19) vaccines. METHODS: A targeted trial emulation study was conducted using data from the National Health Insurance Service database. Vaccinees aged 18-85 years who had received at least one dose of ChAdOx1 or an mRNA-based vaccine were identified. The 42-day risks of AESIs were calculated. RESULTS: A total of 1 767 539 ChAdOx1 vaccinees were matched exactly with mRNA vaccinees according to their risk factors. The 42-day risks of adverse events were low (∼0 to 176 events per 100 000 persons in both vaccine groups), and the incidence rates of AESIs were comparable between the two platforms, except for a higher occurrence of acute cardiac injury (incidence rate ratio [IRR], 1.22; 95% CI, 1.10-1.35), myocarditis or pericarditis (IRR, 2.14; 95% CI, 1.14-4.04), and arrhythmia (IRR, 1.46; 95% CI, 1.24-1.71) in mRNA vaccinees. The incidence of Guillain-Barré syndrome (IRR, 0.20; 95% CI, 0.06-0.69), vasovagal syncope (IRR, 0.77; 95% CI, 0.62-0.97), radiculopathy (IRR = 0.59, 95% CI, 0.41-0.84), and aseptic arthritis (IRR, 0.81; 95% CI, 0.70-0.93) was significantly lower in mRNA-based vaccinees compared with ChAdOx1 vaccinees. DISCUSSION: A remarkable platform-dependent difference was observed in the safety profiles of COVID-19 vaccines, particularly for myocarditis or pericarditis and Guillain-Barré syndrome. However, the overall risk of AESIs was low for both vaccine platforms.

Risk of Severe COVID-19 and Protective Effectiveness of Vaccination Among Solid Organ Transplant Recipients.

BACKGROUND: Solid organ transplant recipients (SOTRs) are at higher risk for severe infection. However, the risk for severe COVID-19 and vaccine effectiveness among SOTRs remain unclear. METHODS: This retrospective study used a nationwide health care claims database and COVID-19 registry from the Republic of Korea (2020 to 2022). Adult SOTRs diagnosed with COVID-19 were matched with up to 4 non-SOTR COVID-19 patients by propensity score. Severe COVID-19 was defined as treatment with high-flow nasal cannulae, mechanical ventilation, or extracorporeal membrane oxygenation. RESULTS: Among 6783 SOTRs with COVID-19, severe COVID-19 was reported with the highest rate in lung transplant recipients (13.16%), followed by the heart (6.30%), kidney (3.90%), and liver (2.40%). SOTRs had a higher risk of severe COVID-19 compared to non-SOTRs, and lung transplant recipients showed the highest risk (adjusted odds ratio, 18.14; 95% confidence interval [CI], 8.53-38.58). Vaccine effectiveness against severe disease among SOTRs was 47% (95% CI, 18%-65%), 64% (95% CI, 49%-75%), and 64% (95% CI, 29%-81%) for 2, 3, and 4 doses, respectively. CONCLUSIONS: SOTRs are at significantly higher risk for severe COVID-19 compared to non-SOTRs. Vaccination is effective in preventing the progression to severe COVID-19. Efforts should be made to improve vaccine uptake among SOTRs, while additional protective measures should be developed.

Development of exosome membrane materials-fused microbubbles for enhanced stability and efficient drug delivery of ultrasound contrast agent.

Lipid-coated microbubbles are widely used as an ultrasound contrast agent, as well as drug delivery carriers. However, the two main limitations in ultrasound diagnosis and drug delivery using microbubbles are the short half-life in the blood system, and the difficulty of surface modification of microbubbles for active targeting. The exosome, a type of extracellular vesicle, has a preferentially targeting ability for its original cell. In this study, exosome-fused microbubbles (Exo-MBs) were developed by embedding the exosome membrane proteins into microbubbles. As a result, the stability of Exo-MBs is improved over the conventional microbubbles. On the same principle that under the exposure of ultrasound, microbubbles are cavitated and self-assembled into nano-sized particles, and Exo-MBs are self-assembled into exosome membrane proteins-embedded nanoparticles (Exo-NPs). The Exo-NPs showed favorable targeting properties to their original cells. A photosensitizer, chlorin e6, was loaded into Exo-MBs to evaluate therapeutic efficacy as a drug carrier. Much higher therapeutic efficacy of photodynamic therapy was confirmed, followed by cancer immunotherapy from immunogenic cell death. We have therefore developed a novel ultrasound image-guided drug delivery platform that overcomes the shortcomings of the conventional ultrasound contrast agent and is capable of simultaneous photodynamic therapy and cancer immunotherapy.

Nationwide Trends in Non-COVID-19 Infectious Disease Laboratory Tests in the Era of the COVID-19 Pandemic in Korea.

The coronavirus disease 2019 pandemic has brought significant changes to infectious disease management globally. This study explored changes in clinical microbiological testing trends and their implications for infectious disease incidence and medical utilization during the pandemic. We collected nationwide claims for monthly clinical microbiology tests from January 2018 to March 2022 using the National Health Insurance Service database. Seasonal autoregressive integrated moving average models were employed to make predictions for each disease based on the baseline period (January 2018 to January 2020). The results showed a significant decrease in general bacterial and fungal cultures, respiratory infectious disease-related, and inflammatory markers, while the representatives of tests for vector-borne diseases, healthcare-associated infections, and chronic viral infections remained stable. The study highlights the potential of clinical microbiological testing trends as an additional surveillance tool and offers implications for future infectious disease management and surveillance strategies in pandemic settings.

Risk of Ischemic Heart Disease in Patients With Postpancreatectomy Diabetes and Pancreatic Cancer: A Population-Based Study.

BACKGROUND: Postpancreatectomy diabetes can be caused by resection of functioning pancreatic tissue and is associated with postoperative pancreatic islet cell mass loss and subsequent endocrine dysfunction. Diabetes is a well-known risk factor for ischemic heart disease. However, no previous studies have investigated ischemic heart disease in patients with postpancreatectomy diabetes and pancreatic cancer. METHODS AND RESULTS: Rates of patients with diabetes diagnosed with pancreatic cancer who underwent pancreatectomy between 2002 and 2019 in South Korea were obtained from the Korean National Health Insurance Service database. Patient-level propensity score matching was conducted to reduce the possibility of selection bias, and multivariate Cox proportional hazards models were used to determine the association between postpancreatectomy diabetes and ischemic heart disease. In total, 30 242 patients were initially enrolled in the study. After applying exclusion criteria and propensity score matching, 2952 patients were included in the comparative analysis between the postpancreatectomy group with diabetes and the group without diabetes. Patients in the postpancreatectomy group with diabetes had significantly higher rates of ischemic heart disease than those in the group without diabetes. In total, 3432 patients were included in the comparison between the postpancreatectomy and prepancreatectomy groups with diabetes. There was no significant difference in the risk of ischemic heart disease between the postpancreatectomy and prepancreatectomy groups with diabetes. CONCLUSIONS: Patients who developed diabetes after pancreatectomy had a higher risk of ischemic heart disease than patients who did not develop diabetes after pancreatectomy, and the rate of ischemic heart disease in these patients was similar to that in patients preoperatively diagnosed with diabetes.

Effective Vaccination and Education Strategies for Emerging Infectious Diseases Such as COVID-19.

Social isolation and control owing to coronavirus disease 2019 (COVID-19) are easing; however, concerns regarding new infectious diseases have not disappeared. Given epidemic experiences such as severe acute respiratory syndrome (SARS), the influenza pandemic, Middle East respiratory syndrome (MERS), and COVID-19, it is necessary to prepare for the outbreak of new infectious diseases and situations in which large-scale vaccinations are required. Although the development of vaccines against COVID-19 has contributed greatly to overcoming the pandemic, concerning vaccine side effects from the general public, including medical personnel, and decreased confidence in vaccine efficacy and side effects, present many challenges in promoting and educating vaccinations for new infectious diseases in the future. In addition to plans to develop vaccines for the outbreak of new infectious diseases, education and promotion plans are necessary to administer the latest developments of vaccines to the general public. Moreover, efforts are needed to secure the necessity, legitimacy, and evidence for rapid vaccination on a large scale at the national level. It is also necessary to carefully prepare scientific bases and explanatory statements so that the general public can easily understand them. This study aimed to establish vaccine strategies and vaccination education plans for new infectious diseases that may occur in the future. Many ways to promote vaccination to the general public and healthcare workers should be prepared to ensure that the latest vaccines against new infectious diseases are administered safely. Thus, education and promotion of vaccine efficacy and safety based on specific data from clinical studies are necessary.

Predictors of COVID-19 Vaccine Hesitancy Among Parents of Children Aged 5-11 Years in Korea.

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.

Inference and forecasting phase shift regime of COVID-19 sub-lineages with a Markov-switching model.

IMPORTANCE: Using regime-switching models, we attempted to determine whether there is a link between changes in severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) variants and infection waves, as well as forecasting new SARS-Cov-2 variants. We believe that our study makes a significant contribution to the field because it proposes a new approach for forecasting the ongoing pandemic, and the spread of other infectious diseases, using a statistical model which incorporates unpredictable factors such as human behavior, political factors, and cultural beliefs.

Lack of association between fluoroquinolone and aortic aneurysm or dissection.

BACKGROUND AND AIMS: An increased risk of aortic aneurysm and aortic dissection (AA/AD) has been reported with fluoroquinolone (FQ) use. However, recent studies suggested confounding factors by indication. This study aimed to investigate the risk of AA/AD associated with FQ use. METHODS: This nationwide population-based study included adults aged ≥20 years who received a prescription of oral FQ or third-generation cephalosporins (3GC) during outpatient visits from 2005 to 2016. Data source was the National Health Insurance Service reimbursement database. The primary outcome was hospitalization or in-hospital death with a primary diagnosis of AA/AD. A self-controlled case series (SCCS) and Cox proportional hazards model were used. Self-controlled case series compared the incidence of the primary outcome in the risk period vs. the control periods. RESULTS: A total of 954 308 patients (777 109 with FQ and 177 199 with 3GC use) were included. The incidence rate ratios for AA/AD between the risk period and the pre-risk period were higher in the 3GC group [11.000; 95% confidence interval (CI) 1.420-85.200] compared to the FQ group (2.000; 95% CI 0.970-4.124). The overall incidence of AA/AD among the patients who received FQ and 3GC was 5.40 and 8.47 per 100 000 person-years. There was no significant difference in the risk between the two groups (adjusted hazard ratio 0.752; 95% CI 0.515-1.100) in the inverse probability of treatment-weighted Cox proportional hazards model. Subgroup and sensitivity analysis showed consistent results. CONCLUSIONS: There was no significant difference in the risk of AA/AD in patients who were administered oral FQ compared to those administered 3GC. The study findings suggest that the use of FQ should not be deterred when clinically indicated.

COVID-19 Vaccination Status Among Korean Pediatric Population With Comorbidities.

The pediatric population with comorbidities is a high-risk group for severe coronavirus disease 2019 (COVID-19). As of January 2023, the COVID-19 vaccination rate for at least two doses among Korean children 5-11 years is low at 1.1%. We summarized the COVID-19 vaccination status for the pediatric population (5-17 years) with comorbidities through July 2022 using the National Health Insurance Service database. Pediatric patients with comorbidities had higher vaccination rates than the general pediatric population (2.4% vs. 1.1% in 5-11-year-olds [P < 0.001], 76.5% vs. 66.1% in 12-17-year-olds [P < 0.001]). However, there were substantial differences according to comorbidity category, and the 2-dose vaccination rate was lowest among children with immunodeficiency in all age groups (1.1% in 5-11-year-olds, 51.2% in 12-17-year-olds). The COVID-19 vaccination rate among Korean children has remained stagnant at a low proportion despite ongoing outreach. Thus, more proactive strategies are needed alongside continuous surveillance.

A Model-Based Cost-Effectiveness Analysis of Long-Acting Monoclonal Antibody (Tixagevimab and Cilgavimab: Evusheld) Preventive Treatment for High-Risk Populations Against SARS-CoV-2 in Korea.

BACKGROUND: Tixagevimab and cilgavimab (Evusheld) administration is a recommended strategy for unvaccinated patients with immunocompromised conditions and severe allergic reaction conditions to protect high-risk individuals and control the coronavirus disease 2019 (COVID-19) epidemic. We estimated the cost-effectiveness of Evusheld in key risk populations: 1) immunocompromised (vaccinated/unvaccinated), 2) severe allergic reaction, and 3) unvaccinated elderly high-risk groups. METHODS: Based on the estimated target risk group population, we used a model of COVID-19 transmission to estimate the size of the risk group population for whom Evusheld treatment may help prevent symptomatic COVID-19 (and deaths) in 2022. We projected Evusheld intervention costs, quality-adjusted life year (QALY) lost, cost averted and QALY gained by reduced COVID-19 incidence, and incremental cost-effectiveness (cost per QALY gained) in each modeled population from the healthcare system perspective. RESULTS: Our study demonstrated that Evusheld treatment for COVID-19 infection in South Korea is highly cost-effective for unvaccinated risk groups ($18,959 per QALY gained for immunocompromised and $23,978 per QALY gained for high-risk elderly groups) and moderately cost-effective among individuals who are vaccinated immunocompromised ($46,494 per QALY gained), or have severe allergic reactions ($45,996 per QALY gained). Evusheld's cost-effectiveness may be subject to risk-group-specific COVID-19 disease progression and Evusheld efficacy and cost, which may change in future epidemic scenarios. CONCLUSION: As the COVID-19 variants and risk group-specific durable efficacy, toxicity (and/or resistance) and optimal dosing of Evusheld remain uncertain, better empirical estimates to inform these values in different epidemiological contexts are needed. These results may help decision-makers prioritize resources toward more equitable and effective COVID-19 control efforts.