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Background Our study aimed to determine the risk of herpes zoster reactivation and coronavirus disease 2019 (COVID-19) vaccination (mRNA vaccine [BNT162b2] and adenovirus-vectored vaccine [ChAdOx1 nCoV-19]). Methods This retrospective study analyzed herpes zoster cases diagnosed between 26 February 2021 and 30 June 2021 and registered in the National Health Insurance Service database. A matched case-control study with a 1:3 matching ratio and a propensity score matching (PSM) study with a 1:1 ratio of vaccinated and unvaccinated individuals were performed. Results In the matched case control analysis, BNT162b2 was associated with an increased risk of herpes zoster reactivation (first dose adjusted odds ratio [aOR], 1.11; 95% confidence interval [CI], 1.06–1.15; second dose aOR, 1.17; 95% CI, 1.12–1.23). PSM analysis revealed a statistically significant increase in risk within 18 days following any vaccination (adjusted hazard ratio [aHR], 1.09; 95% CI, 1.02–1.16). BNT162b2 was associated with an increased risk at 18 days postvaccination (aHR, 1.65; 95% CI, 1.35–2.02) and second dose (aHR, 1.10; 95% CI, 1.02–1.19). However, the risk did not increase in both analyses of ChAdOx1 vaccination. Conclusions mRNA COVID-19 vaccination possibly increases the risk of herpes zoster reactivation, and thus close follow-up for herpes zoster reactivation is required. [ABSTRACT FROM AUTHOR]

• Serotype 3 and 19A were still most prevalent in adults in the era vaccines. • Ceftriaxone non-susceptible rate was high (32.5%) in invasive pneumococci. • Serotypes 11A/E and 19A pneumococci showed low ceftriaxone susceptibility. • Ceftriaxone non-susceptibility was related to sequence type 166 and 320. Invasive pneumococcal disease (IPD) is associated with substantial morbidity and mortality in children and elderly populations. Serotype distribution and antibiotic susceptibility of IPD isolates are changing with the implementation of pneumococcal vaccination and increasing antibiotic use worldwide. We aimed to determine serotype distribution, antibiogram, and molecular epidemiology of pneumococci in the late stage of PCV13 era. Prospective multicenter IPD surveillance study was conducted for adults aged ≥ 19 years from July 2019 to June 2021. Clinical and epidemiologic data were collected. In addition, antibiotic susceptibility test, serotype identification and multi-locus sequence typing (MLST) was taken for pneumococcal isolates. A total of 160 IPD cases were collected with mean age of 65.1 years (male, 72.5%). Serotyping was taken for 116 available pneumococcal isolates. PCV13 and PPSV23 serotypes were 32.8% (n = 38) and 56.0% (n = 65), respectively. Serotype 3 (13.8%) and 19A (9.5%) were the most common causative agents of IPD, followed by serogroup 11 (6.9%), 23A (6.9%), 10A (4.3%), and 15B (4.3%). Notably, 32.5% of invasive pneumococcal isolates were non-susceptible to ceftriaxone. Serotypes 11A, 11E and 19A pneumococci showed high ceftriaxone non-susceptible rate (80%, 100% and 81.8% respectively), and they were related to sequence type (ST) 166 and ST320. In comparison, most serotype 3 isolates were ceftriaxone susceptible and related to ST180. PCV serotypes, especially 3 and 19A, are still prevalent in adult IPDs, suggesting that individual PCV13 immunization would be necessary for the elderly people and chronically ill patients. Ceftriaxone non-susceptible rate was remarkably high in invasive pneumococcal isolates. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antibiotics stewardship program (ASP) in the surgical ICU was implemented. • Comprehensive ASP decreased the use of anti-pseudomonal beta-lactams. • Susceptibilities of anti-pseudomonal beta-lactams were improved during ASP period. • Comprehensive ASP was a factor associated with decreased mortality in surgical ICU. • ASP should be implemented to improve antimicrobial use and patient outcome. We evaluated the effects of a comprehensive antimicrobial stewardship program (ASP) in a surgical intensive care unit (SICU). The ASP was implemented from March 2018 to February 2019 at an SICU in a teaching hospital. An infectious disease physician and a pharmacist visited the SICU 3 times per week for prospective audit and feedback. Outcomes were compared between the ASP period and the same months in the preceding year (pre-ASP period). The primary outcome measure was the use of anti-pseudomonal beta-lactams (APBL). Appropriate antimicrobial de-escalation and ICU mortality rates were also compared. A total of 182 and 149 patients were included in the study for the pre-ASP and ASP periods, respectively. Although disease severity was higher in the ASP group (septic shock 39.0% in pre-ASP vs 65.1% in ASP group, P < 0.001), the use of APBL as a definitive treatment was lower during ASP (68.7% vs 57.7%, OR 0.62, 95% CI 0.40–0.98). Appropriate antimicrobial de-escalation improved (63.2% vs 94.6%, P < 0.001). ICU mortality was comparable (7.7% vs 7.4%) and significantly lower during the ASP, after adjustment (adjusted OR 0.41, 95% CI 0.18–0.92, P = 0.032). A comprehensive ASP decreased the use of APBL and was associated with improved patient outcomes. [ABSTRACT FROM AUTHOR]

Background: After pandemic, A(H1N1)pdm09 is generally known to be associated with younger adults' infection and greater severity than seasonal A(H3N2) but some inconsistences between recent studies exist. Objectives: We aimed to compare the epidemiology and clinical outcomes of A(H1N1)pdm09 and A(H3N2) to verify and consolidate about the knowledge of known differences of subtypes. Methods: Data were retrospectively collected from the hospital‐based influenza morbidity and mortality surveillance in South Korea in nine tertiary care hospitals, from August 31, 2014, to August 25, 2018. Patients with H1N1pdm09 or H3N2 infection admitted in the emergency room or ward were recruited. Results: A total of 1747 patients had influenza A and were divided into two groups those with A(H1N1)pdm09 (n = 240) and those with A(H3N2) (n = 1507). A(H1N1)pdm09 group had younger age (mean age ± standard deviation 50.0 ± 18.8 in H1N1 vs 53.4 ± 21.1 in H3N2, P =.030), lower influenza vaccination (27.9% vs 43.9%, P <.001) and pneumococcal vaccination rates (41.0% vs 51.9%, P <.001), and fewer underlying diseases (67.5% vs 74.0%, P =.035) than the A(H3N2) group. Influenza A subtypes were not associated with pneumonia risk (adjusted odds ratios [AOR] of A(H1N1)pdm09: 0.7 [95% confidence interval [CI]: 0.4‐1.2, P =.172]) and in‐hospital mortality (hazard ratio (HR) of A(H1N1)pdm09: 1.0 (95% CI: 0.3‐3.1, P =.983)). Influenza vaccination reduced in‐hospital mortality in hospitalized patients (HR: 0.3 (95% CI: 0.1‐0.7), P =.005). Conclusions: A(H1N1)pdm09 infection was more common in younger patients without significant difference in pneumonia risk and in‐hospital mortality between subtypes. Influenza vaccination was associated with reduced in‐hospital mortality. [ABSTRACT FROM AUTHOR]

The disease burden of respiratory syncytial virus (RSV) infection in the adult population has not been well characterized compared to children. Investigation of the clinical characteristics and disease burden of adult RSV infection would help to establish public health policy and a future vaccine strategy. We retrospectively collected medical records of hospitalized adult patients who were diagnosed with RSV infection from January 2012 to December 2015 from three tertiary hospitals. Baseline characteristics, clinical outcomes and economic charge during hospitalization were compared by age groups (19–49 years, 50–64 years, and ≥ 65 years) using Chi-square test. The odds of risk factors of RSV pneumonia were calculated using binary logistic regression. A total of 204 patients from three hospitals were enrolled. Patients who older than 65 years were 132 (64.7%). 118 (57.8%) patients had clinically confirmed pneumonia and 22 (10.8%) died in a hospital. The median medical cost of RSV pneumonia was 2,855.26 USD (interquartile range, 1,561.85–5,379.55) per each admission. Solid cancer (adjusted OR, 3.85; 95% CI, 1.65–9.02, p = 0.002) and hematologic malignancy (all patients had pneumonia) were shown to be risk factors for RSV pneumonia. RSV infection in South Korea seemed to have a significant burden among adults as pneumonia, care in the intensive care unit and mortality. Nationwide awareness and further effort to recognize the current burden, prepare specific treatment, and prevent adult RSV infection would be necessary. [ABSTRACT FROM AUTHOR]

Background: Adult seroprevalence of HAV is decreasing in developed countries including South Korea, due to general sanitation improvement. Although hepatitis A vaccination was introduced in South Korea more than 20 years ago, recent infection rates have not decreased. In this study, we investigate the seroprevalence of anti-HAV IgG, and estimate the national disease burden of acute hepatitis A in adult population. Methods: Seroprevalence data were collected from health promotion center of Korea University Guro Hospital, in Seoul, Korea from 2010 to 2014. Data from adults (≥20-years) being tested for anti-HAV IgG were included. In addition, epidemiological and clinical data of patients diagnosed with acute hepatitis A from 2009 to 2013, were collected from Korean Statistical Information Service (KOSIS) and the National Health Insurance Service (NHIS) database. Data were stratified and compared by age groups. Results: A total of 11,177 subjects were tested for anti-HAV IgG from 2010 to 2014. Age-related seroprevalence showed relatively low seropositivity in young adults. Incidence of acute hepatitis A was highest in 2009 and lowest in 2013. When categorized by age group, adults in their 20s and 30s had more HAV infections and related-admissions than older adults. However, ICU admission rate and average insurance-covered cost was high in older adults. Conclusion: The anti-HAV IgG seropositivity in Korean younger adult population was low while the incidence of acute hepatitis A was high, especially in the 20–39 aged. However, a substantial number of older adults were infected, and required more intensive procedures and incurred higher insurance-covered medical costs. [ABSTRACT FROM AUTHOR]

Although some intravenous drugs have been used to treat coronavirus disease 2019 (COVID-19), no effective antiviral agents are currently available in the outpatient setting. We aimed to evaluate the efficacy and adverse events of 14-day ciclesonide treatment vs. standard care for patients with mild-to-moderate COVID-19. A randomized, open-label, multicenter clinical trial of ciclesonide inhalers was conducted in patients with mild-to-moderate COVID-19. Patients were enrolled within 3 days of diagnosis or within 7 days from symptom onset and randomly assigned to receive either ciclesonide (320 µg inhalation twice per day for 14 days) or standard care. The primary endpoint was the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) eradication rate on day 14 from study enrollment. Clinical status was assessed once daily, and serial nasopharyngeal viral load was evaluated by quantitative reverse transcription polymerase chain reaction. There were 35 and 26 patients in the ciclesonide and standard care groups, respectively. The SARS-CoV-2 eradication rate at day 14 was significantly higher in the ciclesonide group (p = 0.021). In multivariate analysis, SARS-CoV-2 negative conversion within 14 days was 12 times more likely in the ciclesonide group (95% confidence interval, 1.187–125.240). Additionally, the clinical failure rate (high-flow nasal oxygen therapy or mechanical ventilation) was significantly lower in the ciclesonide group (p = 0.034). In conclusion, ciclesonide inhalation shortened SARS-CoV-2 viral shedding duration, and it may inhibit the progression to acute respiratory failure in patients with mild-to-moderate COVID-19. Clinical Trial Registration NCT04330586. [ABSTRACT FROM AUTHOR]

Recently, respiratory syncytial virus (RSV) vaccines based on the prefusion F (pre-F) antigen were approved in the United States. We aimed to develop an enzyme-linked immunosorbent assay (ELISA)-based protocol for the practical and large-scale evaluation of RSV vaccines. Two modified pre-F proteins (DS-Cav1 and SC-TM) were produced by genetic recombination and replication using an adenoviral vector. The protocol was established by optimizing the concentrations of the coating antigen (pre-F proteins), secondary antibodies, and blocking buffer. To validate the protocol, we examined its accuracy, precision, and specificity using serum samples from 150 participants across various age groups and the standard serum provided by the National Institute of Health. In the linear correlation analysis, coating concentrations of 5 and 2.5 μg/mL of DS-Cav1 and SC-TM showed high coefficients of determination (r > 0.90), respectively. Concentrations of secondary antibodies (alkaline phosphatase-conjugated anti-human immunoglobulin G, diluted 1:2000) and blocking reagents (5% skim milk/PBS-T) were optimized to minimize non-specific reactions. High accuracy was observed for DS-Cav1 (r = 0.90) and SC-TM (r = 0.86). Further, both antigens showed high precision (coefficient of variation < 15%). Inhibition ELISA revealed cross-reactivity of antibodies against DS-Cav1 and SC-TM, but not with the attachment (G) protein. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

Background: Healthcare-associated pneumonia (HCAP) lies in the intersection of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP). Although HCAP is excluded from the revised HAP guideline, reassessment for HCAP is needed considering its heterogeneous characteristics. Methods: The microbiological distribution, antibiotic resistance, and clinical outcomes in CAP, HCAP, and HAP were studied retrospectively. The susceptibility to standard CAP regimens (β-lactams plus macrolide or fluoroquinolone monotherapy) and rates of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) infections were evaluated in the CAP group and HCAP subgroups. Results: In total, 933 cases were included (CAP, n = 557; HCAP, n = 264; HAP, n = 112). In the CAP and HCAP cases, Streptococcus pneumoniae (7.4% vs. 5.7%) and P. aeruginosa (9.2% vs. 18.6%) were the most common gram-positive and gram-negative pathogens. Staphylococcus aureus (methicillin-resistant, 2.7%; methicillin-susceptible, 2.4%) and carbapenem-resistant Acinetobacter baumannii (20.5%) were the most common Gram-positive and Gram-negative pathogens in the HAP group, respectively. Higher susceptibility to levofloxacin was observed in CAP and HCAP isolates than that to β-lactam agents. However, levofloxacin non-susceptibility was significantly higher in long-term care facility (LTCF)-onset HCAP compared to community-onset HCAP (43.6% vs. 22.7%, P = 0.014). Conclusion: HCAP showed higher rates of P. aeruginosa and MRSA infections than CAP. Empirical antipseudomonal therapy should be considered in the treatment of HCAP. Prior isolation of P. aeruginosa was the most important risk factor for P. aeruginosa infection. [ABSTRACT FROM AUTHOR]

Antiviral treatment reduces the severity and mortality of SARS-CoV-2 infection; however, its effectiveness against long COVID-19 is unclear. This study aimed to evaluate the effectiveness of antiviral drugs in preventing long COVID and related hospitalizations/deaths. Scientific and medical databases were searched from 1 January 2020 to 30 June 2023. We included observational cohort studies comparing individuals receiving early antiviral therapy for COVID-19 and those receiving supportive treatment. A fixed-effects model was used to merge the effects reported in two or more studies. The risk of post-acute sequelae of COVID-19 (PASC) was combined as an odds ratio (OR). Six studies were selected, including a total of 3,352,235 participants. The occurrence of PASC was 27.5% lower in patients who received antiviral drugs during the early stages of SARS-CoV-2 infection (OR = 0.725; 95% confidence interval [CI] = 0.409–0.747) than in the supportive treatment group. Moreover, the risk of PASC-associated hospitalization and mortality was 29.7% lower in patients receiving early antiviral therapy than in the supportive treatment group (OR = 0.721; 95% CI = 0.697–0.794). Early antiviral therapy was associated with a reduced risk of PASC and related hospitalization or death. Thus, early antiviral therapy is recommended for at-risk individuals. [ABSTRACT FROM AUTHOR]

• Heterologous mRNA boost following GLS-5310 DNA vaccination was well tolerated. • Neutralizing antibody responses were enhanced 110 fold to GMT of 1244.8. • Binding antibody responses were enhanced 1,187-fold to GMT of 405,920. • Boosted antibody responses similar to other vaccine combinations. • Boosted T cell responses were many-fold higher than other vaccine combinations. Heterologous boost regimens are being increasingly considered against SARS-CoV-2. We report results for the 32 of 45 participants in the Phase 1 CoV2-001 clinical trial (Kim et al., Int J Iinfect Dis 2023, 128:112–120) who elected to receive an EUA-approved SARS-CoV-2 mRNA vaccine 6 to 8 months following a two-dose primary vaccination with the GLS-5310 bi-cistronic DNA vaccine given intradermally and followed by application of suction using the GeneDerm device. Receipt of EUA-approved mRNA vaccines after GLS-5310 vaccination was well-tolerated, with no reported adverse events. Immune responses were enhanced such that binding antibody titers, neutralizing antibody titers, and T-cell responses increased 1,187-fold, 110-fold, and 2.9-fold, respectively. This paper is the first description of the immune responses following heterologous vaccination with a DNA primary series and mRNA boost. [ABSTRACT FROM AUTHOR]

• Only 1.4% of coronavirus disease 2019 (COVID-19) cases occurred in acute care hospitals in South Korea. • Healthcare personnel accounted for 2.4% of the total patients with COVID-19 in South Korea. • Each hospital should prepare multiple layered defenses to prevent even small cracks in the hospital's quarantine system. • It is necessary to support and strengthen the infection control system of long-term care facilities. Since it first emerged in December 2019, coronavirus disease 2019 (COVID-19) has spread rapidly worldwide. During the pandemic of an emerging infectious disease, it is very important to prevent nosocomial outbreaks and operate hospitals safely to maintain their functions. In this article, we present the strategies for safe hospital operations based on the experiences of the Republic of Korea early in the COVID-19 pandemic. Each hospital should maintain multiple layers of defenses to prevent even small cracks in the hospital's quarantine system. [ABSTRACT FROM AUTHOR]

• This study reports the safety and immunogenicity of the GLS-5310 DNA vaccine through 48 weeks. • First clinical application of the GeneDerm suction device for DNA vaccine delivery. • GLS-5310 was well tolerated and without vaccine-associated severe adverse effects. • T cell responses of ∼1200 site forming units/106 peripheral blood mononuclear cells were maintained through 48 weeks. • T cell responses were many-fold higher than all other vaccine platforms. • Antibody responses were induced in 95.5% and maintained through 48 weeks. The CoV2-001 phase I randomized trial evaluated the safety and immunogenicity of the GLS-5310 bi-cistronic DNA vaccine through 48 weeks of follow-up. A total of 45 vaccine-naïve participants were recruited between December 31, 2020, and March 30, 2021. GLS-5310, encoding for the SARS-CoV-2 spike and open reading frame 3a (ORF3a) proteins, was administered intradermally at 0.6 mg or 1.2 mg per dose, followed by application of the GeneDerm suction device as part of a two-dose regimen spaced either 8 or 12 weeks between vaccinations. GLS-5310 was well tolerated with no serious adverse events reported. Antibody and T cell responses were dose-independent. Anti-spike antibodies were induced in 95.5% of participants with an average geometric mean titer of ∼480 four weeks after vaccination and declined minimally through 48 weeks. Neutralizing antibodies were induced in 55.5% of participants with post-vaccination geometric mean titer of 28.4. T cell responses were induced in 97.8% of participants, averaging 716 site forming units/106 cells four weeks after vaccination, increasing to 1248 at week 24, and remaining greater than 1000 through 48 weeks. GLS-5310 administered with the GeneDerm suction device was well tolerated and induced high levels of binding antibodies and T-cell responses. Antibody responses were similar to other DNA vaccines, whereas T cell responses were many-fold greater than DNA and non-DNA vaccines. [ABSTRACT FROM AUTHOR]

A prospective cohort study was conducted for adults with a diagnosis of with coronavirus disease 2019 (COVID-19). Convalescent blood samples were obtained 4, 6, and 11 months after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The seropositivity of anti-spike antibody was maintained in all patients (100%) until 11 months after COVID-19 diagnosis. Neutralizing antibody levels against wild-type SARS-CoV-2 gradually decreased but remained positive in >50% of patients 11 months after diagnosis: in 98.5% (67 of 68) at 4 months, 86.8% (46 of 53) at 6 months, and 58.8% (40 of 68) at 11 months. However, cross-neutralizing activity against the Beta and Delta variants was attenuated 2.53-fold and 2.93-fold, respectively, compared with the wild-type strain. [ABSTRACT FROM AUTHOR]

Face masks are used to protect the wearer from harmful external air and to prevent transmission of viruses from air exhaled by potentially infected wearers to the surrounding people. In this study, we examined the potential utility of masks for collecting viruses contained in exhaled breath and detected the collected viruses via various molecular tests. Using KF94 masks, the inner electrostatic filter was selected for virus collection, and an RNA extraction protocol was developed for the face mask. Virus detection in worn mask samples was performed using PCR and rolling circle amplification (RCA) tests and four different target genes (N, E, RdRp, and ORF1ab genes). The present study confirmed that the mask sample tests showed positive SARS-CoV-2 results, similar to the PCR tests using nasopharyngeal swab samples. In addition, the quantity of nucleic acid collected in the masks linearly increased with wearing time. These results suggest that samples for SARS-CoV-2 tests can be collected in a noninvasive, quick, and easy method by simply submitting worn masks from subjects, which can significantly reduce the hassle of waiting at airports or public places and concerns about cross-infection. In addition, it is expected that miniaturization technology will integrate PCR assays on face masks in the near future, and mask-based self-diagnosis would play a significant role in resolving the pandemic situation. [ABSTRACT FROM AUTHOR]

Background: Despite use of the 13-valent pneumococcal conjugate vaccine (PCV13) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) over the last decade, the disease burden of pneumococcal pneumonia is still high. We evaluated the field effectiveness of PCV13, PPSV23, and sequential vaccination against pneumococcal pneumonia in older adults.Methods: This prospective multicenter study was conducted in adults aged ≥65 years hospitalized with community-acquired pneumonia (CAP) between September 2015 and August 2017. The case-control test-negative design was used to estimate vaccine effectiveness (VE) against pneumococcal CAP.Results: Of 1525 cases with CAP hospitalization, 167 (11.0%) were identified as pneumococcal CAP. In the elderly aged ≥65 years, the adjusted VE of pneumococcal vaccines against pneumococcal CAP was statistically insignificant: 40.0% (95% confidence interval [CI], -10.8% to 67.5%) for PCV13 and 11.0% (95% CI, -26.4% to 37.3%) for PPSV23. However, in the younger subgroup (aged 65-74 years), sequential PCV13/PPSV23 vaccination showed the highest adjusted VE of 80.3% (95% CI, 15.9%-95.4%), followed by single-dose PCV13 (adjusted VE, 66.4% [95% CI, .8%-88.6%]) and PPSV23 (adjusted VE, 18.5% [95% CI, -38.6% to 52.0%]).Conclusions: Sequential PCV13/PPSV23 vaccination is most effective for preventing pneumococcal CAP among the elderly aged 65-74 years. [ABSTRACT FROM AUTHOR]

There is insufficient data on the longevity of immunity acquired following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We aimed to evaluate the duration of SARS-CoV-2-specific humoral and cellular immunity according to the clinical severity of coronavirus disease 2019 (COVID-19). The study population comprised asymptomatic (n=14), symptomatic/non-pneumonic (n=42), and pneumonic (n=41) patients. The anti-SARS-CoV-2 IgG and neutralizing antibody (NAb) titers lasted until six months after diagnosis, with positivity rates of 66.7% and 86.9%, respectively. Older age, prolonged viral shedding and accompanying pneumonia were more frequently found in patients with sustained humoral immunity. SARS-CoV-2 specific T-cell response was strongly observed in pneumonic patients and prominent in individuals with sustained humoral immunity. In conclusion, most (> 85%) patients carries NAb until six months after diagnosis of SARS-CoV-2 infection, providing insights for establishing vaccination strategies against COVID-19. [ABSTRACT FROM AUTHOR]

With global warming and lush forest change, vector-borne infections are expected to increase in the number and diversity of agents. Since the first report of severe fever with thrombocytopenia syndrome (SFTS) in 2013, the number of reported cases has increased annually in South Korea. However, although tick-borne encephalitis virus (TBEV) was detected from ticks and wild rodents, there is no human TBE case report in South Korea. This study aimed to determine the seroprevalence of TBEV and SFTS virus (SFTSV) among forest and field workers in South Korea. From January 2017 to August 2018, a total 583 sera were obtained from the forest and field workers in South Korea. IgG enzyme-linked immunosorbent assay (ELISA) and neutralization assay were conducted for TBEV, and indirect immunofluorescence assay (IFA) and neutralization assay were performed for SFTSV. Seroprevalence of TBEV was 0.9% (5/583) by IgG ELISA, and 0.3% (2/583) by neutralization assay. Neutralizing antibody against TBEV was detected in a forest worker in Jeju (1:113) and Hongcheon (1:10). Only 1 (0.2%) forest worker in Yeongju was seropositive for SFTSV by IFA (1:2,048) and neutralizing antibody was detected also. In conclusion, this study shows that it is necessary to raise the awareness of physicians about TBEV infection and to make efforts to survey and diagnose vector-borne diseases in South Korea. Author summary: With global warming and lush forest change, vector-borne infections are expected to increase in the number and diversity of agents. Since the first report of severe fever with thrombocytopenia syndrome (SFTS) in 2013, the number of reported cases has increased annually in South Korea. However, although tick-borne encephalitis virus (TBEV) was detected from ticks and wild rodents, there is no human TBE case report in South Korea. This study aimed to determine the seroprevalence of TBEV and SFTS virus (SFTSV) among forest and field workers in South Korea. Among 583 forest/field workers, the seroprevalence of neutralizing antibodies against TBEV and SFTSV were 0.3% (2/583) and 0.2% (1/583), respectively. This study shows that it is necessary to raise the awareness of physicians about TBEV infection and to make efforts to survey and diagnose vector-borne diseases in South Korea. [ABSTRACT FROM AUTHOR]

Background: Pneumonia is a leading infectious cause of morbidity and mortality among adults. Pneumococcal pneumonia (PP) is the most common vaccine-preventable bacterial etiology of pneumonia. In this study, we estimated the incidence of community-acquired pneumonia (CAP) and pneumococcal diseases among Korean adults. Methods: Clinical and microbiological databases from three hospitals were retrospectively reviewed to determine the incidence and case fatality rates of CAP and pneumococcal diseases in Korean adults aged ≥19 years from 2011 to 2014. Incidence and case fatality rates of CAP, PP and invasive pneumococcal diseases (IPD) were evaluated based on the catchment population. Catchment population was calculated using national health insurance data, estimating the proportion of patients with pneumonia that were medically attended at each hospital. Results: Among 5,783 patients with medically attended CAP, 833 (14.4%) had PP. For IPD, a total of 91 culture-confirmed cases were identified. The overall incidence of CAP was 307.7 cases per 100,000 persons per year with an in-hospital mortality rate of 6.2%. The estimated annual incidence of pneumococcal pneumonia was 42.2–49.4 cases per 100,000 persons per year, increasing with age to >280 per 100,000 persons per year in older patients over 70 years. The annual incidence of IPD had a range of 4.1–6.5 cases per 100,000 persons per year. The overall case fatality rate for invasive pneumococcal diseases was 30.8% with the highest rate of 66.7% in patients over 80 years. Conclusion: Over the study period, incidences of CAP, PP and IPD were consistently high, particularly in older people. These results provide baseline data to establish healthcare strategies and estimate their impact among Korean adults. [ABSTRACT FROM AUTHOR]

Background Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne disease characterized by high fever, thrombocytopenia, leukopenia, and multiple organ failure and is caused by a novel bunyavirus. Human-to-human transmission has been reported previously, but the mode of transmission has not been clarified thoroughly. Study design We identified a case of a 73-year-old woman with SFTS and performed a semi-quantitative real-time reverse transcription PCR (real-time RT-PCR) assay on her blood, tracheal aspirate, gastric aspirate and urine to detect SFTS virus (SFTSV). Results During 7-day hospitalization, all the serum samples showed positive C t values lower than 35 in both the S and M segments, suggesting the presence of the SFTSV RNA. After initiation of plasma exchange, serum SFTSV load markedly decreased, but still remained positive. The SFTS viral RNA was also detected in other body fluids, including tracheal aspirate and gastric aspirate. Conclusion These results suggest that droplet transmission can occur through close contact with infected patients. [ABSTRACT FROM AUTHOR]

Social distancing is an effective measure to mitigate the spread of novel viral infections in the absence of antiviral agents and insufficient vaccine supplies. Subway utilization density may reflect social activity and the degree of social distancing in the general population.; This study aimed to evaluate the correlations between subway use density and the activity of the influenza epidemic or coronavirus disease 2019 (COVID-19) pandemic using a time-series regression method. The subway use-based social distancing score (S-SDS) was calculated using the weekly ridership of 11 major subway stations. The temporal association of S-SDS with influenza-like illness (ILI) rates or the COVID-19 pandemic activity was analyzed using structural vector autoregressive modeling and the Granger causality (GC) test. During three influenza seasons (2017–2020), the time-series regression presented a significant causality from S-SDS to ILI (p = 0.0484). During the COVID-19 pandemic in January 2020, S-SDS had been suppressed at a level similar to or below the average of the previous four years. In contrast to the ILI rate, there was a negative correlation between COVID-19 activity and S-SDS. GC analysis revealed a negative causal relationship between COVID-19 and S-SDS (p = 0.0098).; S-SDS showed a significant time-series association with the ILI rate but not with COVID-19 activity. When public transportation use is sufficiently suppressed, additional social mobility restrictions are unlikely to significantly affect COVID-19 pandemic activity. It would be more important to strengthen universal mask-wearing and detailed public health measures focused on risk activities, particularly in enclosed spaces. [ABSTRACT FROM AUTHOR]

Background: When two or more vaccines are administered concurrently, there is concern about safety and immunogenicity from vaccine interaction.Methods: Subjects aged ≥50 years were randomized 1:1:1 to receive tetanus-diphtheria (Td) + 13-valent pneumococcal conjugate vaccine (PCV13; Group 1), PCV13 alone (Group 2), or Td alone (Group 3). After single or concomitant vaccination, enzyme-linked immunosorbent assay and opsonophagocytic assay (OPA) were performed to compare immunogenicity for Td and PCV13, respectively.Results: A total of 448 subjects were available for the assessment. After concomitant administration, the non-inferiority criteria of geometric mean titer (GMT) ratios were met for tetanus, diphtheria, and all four pneumococcal serotypes (1, 5, 18C, and 19A). However, subjects in Group 3 (Td alone) were more likely to have a high IgG anti-tetanus antibody titer (≥ 0.5 U/mL) than those in Group 1 (Td + PCV13) (p <  0.01). As for the pneumococcal serotype 1, the OPA GMT was significantly higher in Group 1 (PCV13 + Td) compared to Group 2 (PCV13 alone) (p = 0.02). No serious adverse event occurred.Conclusions: Concomitant Td and PCV13 administration induced sufficient immunity without significant interference and showed good safety profiles.Trials Registration: NCT03552445 registered at http://www.clinicaltrials.gov on June 11, 2018 (retrospectively registered). [ABSTRACT FROM AUTHOR]