Real-World Epidemiology, Treatment Patterns, and Disease Burden of Chronic Hepatitis B and HDV Co-Infection in South Korea.

INTRODUCTION: Long-term complications of chronic hepatitis B (CHB) viral infection, such as cirrhosis, hepatocellular carcinoma (HCC), and liver failure, cause a large disease burden. This study aimed to describe the epidemiology, clinical outcomes, and treatment patterns of CHB infection and co-infection with hepatitis D virus (HDV) in South Korea. METHODS: The retrospective, observational study used existing data from the Health Insurance Review and Assessment Service (HIRA) database. Confirmed cases of (CHB) and HBV/HDV co-infection were identified between 2013 and 2019. Hepatitis C virus co-infections and acute HBV infections were excluded. Incident cases diagnosed between 2015 and 2018 with no prior disease history up to 2 years were included. Patient characteristics, clinical outcomes, economic burden, and healthcare-resource utilization were described. RESULTS: The estimated 7-year prevalence of CHB and HBV/HDV co-infection were 0.9% and 0.0024%, respectively. The prevalence was higher among 45-54 years old (CHB: 1.6%, HBV/HDV: 0.0049%) and males (1.1%, 0.0035%). The 5-year cumulative incidences of compensated cirrhosis, decompensated cirrhosis, HCC, and liver transplantation were 13.3%, 7.1%, 8.4%, and 0.7%, respectively. Hyperlipidemia (40.6%), hypertension (23.5%), and peptic ulcer (23.7%) were the more prevalent comorbidities. Among CHB patients, 48.1% received ≥ 1 prescribed anti-HBV drug including interferon or nucleos(t)ide analogues and 64.4% had ≥ 1 hospitalization compared to 80.4% and 79.4% HBV/HDV patients. Estimated total healthcare costs for CHB and HBV/HDV were US$786 million and $62 million, respectively. CONCLUSIONS: These findings provide insights to the epidemiology, clinical burden, treatment patterns, and healthcare costs of CHB and HBV/HDV co-infection in South Korea.

Cost-effectiveness of a national immunization program with the 13-valent pneumococcal conjugate vaccine compared with the 10-valent pneumococcal conjugate vaccine in South Korea.

INTRODUCTION: Globally, pneumococcal disease represents a significant burden. South Korea implemented the 7-valent pneumococcal conjugate vaccine (PCV7) in 2003, replaced with the 10-valent (PCV10) and 13-valent (PCV13) vaccine in 2010. In 2014, both vaccines were introduced in the national immunization program (NIP) for infants with 3 primary doses and one booster dose We performed a cost-effectiveness evaluation to elucidate which vaccine may be expected to provide greater impact if included in a NIP. METHODOLOGY: Using an established model, we estimated the impact of introducing either PCV13 or PCV10 into the South Korean NIP in 2015. Vaccine impact was based on historic observed impact of PCV13 from 2010 to 2015 in Korea given high uptake of PCV13, and PCV10 impact was estimated based on experiences in countries using PCV10. Incidence and costs for all ages and including invasive pneumococcal disease, pneumonia, and acute otitis media were derived from the literature and Health Insurance Review and Assessment database. RESULTS: In the base-case, over 5-years PCV13 was estimated to avert 550,000 more cases of pneumococcal disease compared to PCV10, driven by broader serotype coverage and less replacement due to serotypes 3 and 19A. This translated to a cost-savings of $47.4 million USD despite PCV13's higher cost. Sensitivity analysis found incremental cost-effectiveness ratios (ICERs) ranged from cost-saving to $7,300 USD per quality-adjusted life year (QALY). CONCLUSION: A NIP using PCV13 was estimated to have a more substantial public health impact and be cost-saving compared to a program with PCV10 due to broader serotype coverage.

Environmental factors which can affect the burden of pneumococcal disease and the immune response to pneumococcal vaccines: the need for more precisely delineated vaccine recommendations.

Introduction: Precision medicine describes the customization of healthcare tailored to the individual patient. Generally, vaccines are considered as public health tools rather than from the individual patient perspective. However, adult vaccination programs in particular should consider many different factors, at the individual level and also from societal, cultural and country-specific perspectives. Currently, most immunization programs, including those for pneumococcal vaccines, have only been adopted on the basis of age or medical risk. Areas covered: Based on a broad literature search, this review addresses possible environmental factors which can affect the burden of pneumococcal disease and the immune response to pneumococcal vaccines. Expert opinion: Factors which influence the incidence of pneumococcal disease and the reaction against pneumococcal vaccination, including personal conditions, geographic/ethnic factors and social risks, are diverse. To maximize the effects of pneumococcal vaccination, not only for public health but also to induce optimal effects at the individual level, vaccines need to be verified under diverse situations and with collaboration among relevant medical societies, governments, and the pharmaceutical industry. Whereas vaccines are generally considered only from the public health perspective, flexible, comprehensive and tailored pneumococcal immunization programs, with appropriate policy support, can generate a greater positive impact on public health.

Cost-effectiveness analysis of 13-valent pneumococcal conjugate vaccine versus 23-valent pneumococcal polysaccharide vaccine in an adult population in South Korea.

In South Korea, the National Immunization Program offers a 23-valent pneumococcal polysaccharide vaccine (PPSV23) for the elderly; however, the 13-valent pneumococcal conjugate vaccine (PCV13) is not included, and vaccination is not offered to younger, at-risk populations. This study offers a comparative analysis of PCV13 and PPSV23 in Korea's adults, stratified by age and risk group. A Markov model with a lifetime horizon was developed from the healthcare perspective. Data sources included the Health Insurance Review & Assessment Service, Korea Centre for Disease Control & Prevention and Korean medical institutions. An expert panel tested data validity. The CAPiTA trial and Cochrane meta-analysis were used to obtain vaccine effectiveness data. Regardless of co-morbidity, when the sequential PCV13-PPSV23 strategy was compared to that using PPSV23-only, in elderly populations, the incremental cost-effectiveness ratio (ICER) was 3,300 USD per quality-adjusted life years (QALY). For the risk group aged ≥65 years, the ICER of the addition of PCV13 over the existing PPSV23-only strategy was 3,404 USD/QALY. However, on replacing PPSV23 with PCV13, for all elderly populations, an ICER of 1,421 USD/QALY resulted; for the risk group aged ≥65 years, the ICER was 1,736 USD/QALY. For the 18-64 year-old risk group, the sequential PCV13-PPSV23 strategy yielded an ICER of 3,629 USD/QALY over the PPSV23-only strategy, and 6,643 USD/QALY compared to no vaccination. Thus, the PCV13→PPSV23 combination strategy for elderly populations was found to be a cost-effective alternative to the current National Immunization Program regardless of co-morbidity. This finding was the same as that for younger, at-risk populations.

Assessment of Extent and Role of Tau in Subcortical Vascular Cognitive Impairment Using 18F-AV1451 Positron Emission Tomography Imaging.

Importance: Amyloid-ß (Aß), tau, and cerebral small vessel disease (CSVD), which occasionally coexist, are the most common causes of cognitive impairments in older people. However, whether tau is observed in patients with subcortical vascular cognitive impairment (SVCI), as well as its associations with Aß and CSVD, are not yet established. More importantly, the role of tau underlying cognitive impairments in SVCI is unknown. Objective: To investigate the extent and the role of tau in patients with SVCI using 18F-AV1451, which is a new ligand to detect neurofibrillary tangles in vivo. Design, Setting, and Participants: This cross-sectional study recruited 64 patients with SVCI from June 2015 to December 2016 at Samsung Medical Center, Seoul, Korea. The patients had significant ischemia on brain magnetic resonance imaging, defined as periventricular white matter hyperintensity at least 10 mm and deep white matter hyperintensity at least 25 mm. We excluded 3 patients with SVCI owing to segmentation error during AV1451 positron emission tomography analysis. Main Outcomes and Measures: We calculated CSVD scores based on the volumes of white matter hyperintensities, numbers of lacunes, and microbleeds using magnetic resonance imaging data. The presence of Aß was assessed using fluorine 18-labeled (18F) florbetaben positron emission tomography. Tau was measured using 18F-AV1451 positron emission tomography. We determined the spreading order of tau by sorting the regional frequencies of cortical involvement. We evaluated the complex associations between Aß, CSVD, AV1451 uptake, and cognition in patients with SVCI. Results: Of the 61 patients with SVCI, 44 (72.1%) were women and the mean (SD) age was 78.7 (6.3) years. Patients with SVCI, especially patients with Aß-negative SVCI, showed higher AV1451 uptake in the inferior temporal areas compared with normal control individuals. In patients with SVCI, Aß positivity and CSVD score were each independently associated with increased AV1451 uptake in the medial temporal and inferior temporal regions, respectively. Involvement frequency of AV1451 uptake in the fusiform gyrus, inferior temporal, and precuneus regions were higher than that in the parahippocampal region. In patients with SVCI, higher AV1451 uptake in the inferior temporal and medial temporal regions correlated with worse language and general cognitive function. In patients with SVCI, Aß positivity and CSVD score each correlated with worse general cognitive function, which was completely mediated by AV1451 uptake in the entorhinal cortex and inferior temporal gyrus, respectively. Conclusions and Relevance: Our findings suggest that in SVCI, both Aß and CSVD were independently associated with increased tau accumulation. Furthermore, tau burden played a pivotal role because it was the final common pathway for the cognitive impairment in patients with SVCI.

Tick-borne encephalitis in Japan, Republic of Korea and China.

Tick-borne encephalitis virus (TBEV) causes mild or moderate febrile illness in humans that may progress to encephalitis, leading to severe long-term complications and sometimes death. TBEV is prevalent in the Eurasian continent and has been isolated in China, Japan and Republic of Korea (ROK). The TBEV isolates from Japan are of the Far-Eastern subtype; in ROK, the isolates are of the Western subtype; and all TBEV isolates in China are of the Far-Eastern subtype, except one strain that was identified most recently as the Siberian subtype. TBE is endemic to the northeast, northwest and southeast of China; only two confirmed TBE cases have been reported in Japan to date; and no TBE case has been confirmed in ROK. For TBE patients in China, the onset of disease is acute with no biphasic course for disease presentation. The clinical spectrum of disease phenotypes may be wider than currently understood, since serological evidence suggests the presence of TBEV infections in healthy people, indicating that asymptomatic or unspecific manifestations of TBEV infection may exist. The current treatment for TBE is supportive care. In China, vaccines against TBEV have been developed and are available with demonstrated immunogenicity and safety, although efficacy data are lacking. No vaccines are available in ROK or Japan.