Broad humoral and cellular immunity elicited by one-dose mRNA vaccination 18 months after SARS-CoV-2 infection

Practical guidance is needed regarding the vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals in resource-limited countries. It includes the number of vaccine doses that should be given to unvaccinated patients who experienced COVID-19 early in the pandemic. We recruited COVID-19 convalescent individuals who received one or two doses of an mRNA vaccine within 6 or around 18 months after a diagnosis of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Their samples were assessed for IgG-binding or neutralizing activity and cell-mediated immune responses against SARS-CoV-2 wild-type and variants of concern. A total of 43 COVID-19 convalescent individuals were analyzed in the present study. The results showed that humoral and cellular immune responses against SARS-CoV-2 wild-type and variants of concern, including the Omicron variant, were comparable among patients vaccinated within 6 versus around 18 months. A second dose of vaccine did not significantly increase immune responses. One dose of mRNA vaccine should be considered sufficient to elicit a broad immune response even around 18 months after a COVID-19 diagnosis.This work was supported in part by the Bio & Medical Technology Develop‑ ment Program of the National Research Foundation (NRF) & funded by the Korean government (MSIT) (2021M3A9I2080496, to H.-R. Kim & W. B. Park), the Creative-Pioneering Researchers Program through Seoul National University (to C.-H. Lee), and the Seoul National University Hospital Research Fund (112021-5050 to P. G. Choe and 800-20220110 to C.-H. Lee)

Clinical application of the Panbio™ COVID-19 Ag rapid test device and SSf-COVID19 kit for the detection of SARS-CoV-2 infection

Objective We evaluated the sensitivity and specificity of the Panbio™ COVID-19 Ag rapid test device using nasal swabs and those of the SSf-COVID19 kit, one of RT-PCR tests, using saliva specimens. These tests were compared with RT-PCR tests using nasopharyngeal swabs for the diagnosis of SARS-CoV-2 infection. The three diagnostic tests were simultaneously conducted for patients aged ≥ 18 years, who were about to be hospitalized or had been admitted for COVID-19 confirmed by RT-PCR in two research hospitals from August 20 to October 29, 2021. Nasal swabs were tested using the Panbio™ COVID-19 Ag rapid test device. More than 1 mL of saliva was self-collected and tested using the SSf-COVID19 kit. Results In total, 157 patients were investigated; 124 patients who were about to be hospitalized and 33 patients already admitted for COVID-19. The overall sensitivity and specificity of the Panbio™ COVID-19 Ag rapid test device with nasal swabs were 64.7% (95% confidence interval [CI] 47.9–78.5%) and 100.0% (95% CI 97.0–100.0%), respectively. The median time to confirm a positive result was 180 s (interquartile range 60–255 s). The overall sensitivity and specificity of the SSf-COVID19 kit with saliva specimens were 94.1% (95% CI 80.9–98.4%) and 100.0% (95% CI 97.0–100.0%), respectively.This work was supported by a grant from research fund of Seoul National University Hospital (Grant No. 2021–3148

Development of a Brain–Computer Interface Toggle Switch with Low False-Positive Rate Using Respiration-Modulated Photoplethysmography

Asynchronous brain–computer interfaces (BCIs) based on electroencephalography (EEG) generally suffer from poor performance in terms of classification accuracy and false-positive rate (FPR). Thus, BCI toggle switches based on electrooculogram (EOG) signals were developed to toggle on/off synchronous BCI systems. The conventional BCI toggle switches exhibit fast responses with high accuracy; however, they have a high FPR or cannot be applied to patients with oculomotor impairments. To circumvent these issues, we developed a novel BCI toggle switch that users can employ to toggle on or off synchronous BCIs by holding their breath for a few seconds. Two states—normal breath and breath holding—were classified using a linear discriminant analysis with features extracted from the respiration-modulated photoplethysmography (PPG) signals. A real-time BCI toggle switch was implemented with calibration data trained with only 1-min PPG data. We evaluated the performance of our PPG switch by combining it with a steady-state visual evoked potential-based BCI system that was designed to control four external devices, with regard to the true-positive rate and FPR. The parameters of the PPG switch were optimized through an offline experiment with five subjects, and the performance of the switch system was evaluated in an online experiment with seven subjects. All the participants successfully turned on the BCI by holding their breath for approximately 10 s (100% accuracy), and the switch system exhibited a very low FPR of 0.02 false operations per minute, which is the lowest FPR reported thus far. All participants could successfully control external devices in the synchronous BCI mode. Our results demonstrated that the proposed PPG-based BCI toggle switch can be used to implement practical BCIs

Kinetics of Neutralizing Antibody Responses Against SARS-CoV-2 Delta Variant in Patients Infected at the Beginning of the Pandemic

We investigated the kinetics of the neutralizing antibody responses to the severe acute respiratory syndrome-coronavirus-2 delta variant over the course of 1 year in 16 patients infected at the beginning of the pandemic. In patients with severe disease, neutralizing responses to the delta variant were detectable, albeit at lower levels than responses to the wild type. Neutralizing responses to the delta variant were undetectable, however, in asymptomatic persons. This finding implies that the vaccination strategy for persons with past natural infection should depend on the severity of the previous infection.N

A Direct Rapid Phenotypic Antimicrobial Susceptibility Test Enables Early Selection of Optimal Antibiotics to Treat Bacteremia in COVID-19 Patients

Background: Co-infection with bacteria and severe acute respiratory syndrome coronavirus 2 may result in greater use of healthcare resources and a poor prognosis. Therefore, early selection and use of optimal antibiotics are essential. The direct rapid antibiotic susceptibility test (dRAST) can detect antibiotic resistance within 6 h of a Gram smear result. This study aimed to assess the effectiveness of dRAST for improving early selection of appropriate antibiotics for coronavirus disease 2019 (COVID-19) patients with bacteremia. Materials and Methods: This retrospective study included 96 blood culture-positive COVID-19 patients. Bacterial isolates and antimicrobial resistance profiles of each case were evaluated. Cases were divided into two groups based on whether they underwent conventional antibiotic susceptibility test (AST) or dRAST. The time to optimal targeted treatment for the two groups was investigated and compared. In addition, we examined the proportion of cases for which appropriate antibiotics were selected and broad spectrum antibiotics were administered at 72 h from blood sample collection. Results: The mean time to optimal targeted antibiotic treatment was shorter for the dRAST group [55.7; standard deviation (SD), 28.7 vs. 92.3; SD, 51.1 h; P = 0.041]. The proportion of cases receiving optimal targeted antibiotics 72 h after blood collection for culture was higher [6/10 (60.0%) vs. 10/25 (40.0%)] and the percentage receiving broad spectrum antibiotics at 72 h was lower [6/10 (60.0%) vs. 19/25 (76.0%)] in the dRAST group than in the conventional AST group. In terms of microbiology profile, the contamination rate was high (35.5%) and multidrug-resistant strains were common (63.2%) in COVID-19 patients with bacteremia. Conclusion: Application of dRAST for selection of antibiotics to treat bacteremia in COVID-19 patients may enable earlier and optimal treatment. The high incidence of contamination and resistant organisms in blood cultures from COVID-19 patients suggest that dRAST may speed up appropriate targeted treatment.N

Clinical Impact of Empirical Antibiotic Therapy in Patients With Coronavirus Disease 2019 Requiring Oxygen Therapy

Despite the low prevalence of secondary bacterial infection in coronavirus disease 2019 (COVID-19) patients, most of them were administered antibiotic therapy empirically. However, the prognostic impact of empirical antibiotic therapy has not been evaluated. We conducted retrospective propensity score-matched case-control study of 233 COVID-19 patients with moderate to severe illnesses who required oxygen therapy and evaluated whether empirical antibiotic therapy could improve clinical outcomes. Empirical antibiotic therapy did not improve clinical outcomes including length of stay, days with oxygen requirement, the proportion of patients with increased oxygen demand, the proportion of patients who required mechanical ventilation, and overall mortality. This finding implies that routine administration of antibiotics for the treatment of COVID-19 is not essential and should be restricted.N

Effectiveness of antimicrobial stewardship programmes based on rapid antibiotic susceptibility testing of haematological patients having high-risk factors for bacteraemia-related mortality: a post-hoc analysis of a randomised controlled trial

A randomised controlled trial showed that rapid phenotypic antibiotic susceptibility testing (AST) with antimicrobial stewardship programme (ASP) increases the proportion of haematological patients with bacteraemia receiving optimal targeted therapy within 72 h of blood culture collection. This post-hoc analysis aimed to evaluate the effects of rapid phenotypic AST intervention in haematological patients at high risk of a poor outcome from bacteraemia. Haematological patients with bacteraemia ( n = 116) were assigned randomly to a conventional AST group or a rapid AST group. The two outcome measures were the proportion of patients receiving optimal targeted therapy at 72 h post blood culture collection and the time to optimal targeted therapy; subgroup analysis was conducted based on baseline demographics (age, sex) and prognostic (Charlson comorbidity index, haematological treatment intensity, Pitt bacteraemia score, appropriateness of empirical antibiotic therapy and multidrug-resistant organism) indicators. The interaction effect between the intervention and subgroup factors was examined using regression model analysis. Age, sex, Charlson comorbidity index, haematological treatment intensity, Pitt bacteraemia score and appropriateness of empirical antibiotic therapy had no significant interaction effects on the proportion of patients receiving optimal targeted therapy ( P = 0.129-0.826). However, infection by a multidrug-resistant organism did have a significant interaction effect ( P = 0.042). Regarding time to optimal targeted therapy, there were no significant interaction effects between the intervention and subgroup factors ( P = 0.156-0.848). In conclusion, rapid phenotypic AST with ASP intervention may accelerate early optimal targeted antimicrobial treatment of haematological patients, even those in highrisk subgroups with bacteraemia. (c) 2022 Elsevier Ltd and International Society of Antimicrobial Chemotherapy. All rights reserved.N

Application of the severe fever with thrombocytopenia syndrome prediction score: Differentiation of febrile diseases using basic laboratory parameters.

BACKGROUND:The prolonged manifestation of concurrent leukopenia, thrombocytopenia and normal C-reactive protein (CRP) (named as SFTS prediction score) in febrile diseases is not usual and may be used to make an initial differential diagnosis, which is a characteristic finding of severe fever with thrombocytopenia syndrome (SFTS). METHODS:The dynamics of SFTS prediction scores was investigated in SFTS patients. The study subjects for the comparison were febrile patients aged ≥ 16 years with SFTS scores of 2 (S2) or 3 (S3) who visited an emergency room for a 4-year study period. The dynamic distribution of S2 and S3 at presentation with regards to onset of illness, the characteristics of responsible diseases and the predictability of SFTS in both groups were described. RESULTS:In 104 patients with SFTS, the daily proportion of S2 or S3 ranged from 58.3 to 100% from day (D) 1 to D12 after the onset of illness. The S2 subtype of 'leukopenia plus thrombocytopenia' and S3 represented 72.7-100% of all scores. In contrast, for the 130 patients in the febrile cohort, 73.8% of evaluations were distributed between D1 and D4 after the onset of illness, and 68.8% of patients had the S2 subtype of 'leukopenia plus normal CRP'. Upper respiratory infection was the most frequent (50.0%) cause of diseases. Pneumonia (13.8%) and urosepsis (6.2%) initially presented with either S2 with normal CRP or S3 but had poor prognosis. The presence of S2 or S3 predicted SFTS with sensitivity and specificity of 0.85 (0.42-0.99; 95% CI) and 0.98 (0.98-0.98; 95% CI), respectively. CONCLUSION:The temporal distribution and composition of S2 or S3 were unique in several febrile diseases including SFTS, and the SFTS prediction score may be useful for differentiating febrile diseases in primary care settings of SFTS endemic areas

The Importance of Proper History Taking: Asking a Fever Pattern in Patients with Vivax Malaria

Characteristic fever patterns of malarial infection are clues for diagnosis. However, checking fever patterns in febrile patients has been usually missed, and unnecessary tests have been performed. We reviewed electrical medical record to check whether history-taking included questions on fever pattern in febrile patients. Main outcomes were time interval between visit and diagnosis of vivax malaria and proportion of patients who had taken unnecessary tests. Among 134 vivax malarial patients, asking about fever pattern was done in 64 (47.8%). Median time interval between visit and diagnosis was significantly shorter in patients whose fever pattern was asked than those not asked (3.2 hours vs. 18.6 hours; P < 0.001). Unnecessary diagnostic tests were conducted in 27% (17/64) of patients asked about fever pattern and 71% (50/70) in patients not asked (P < 0.001). Proper history-taking can reduce time elapsed for diagnosis and performing unnecessary diagnostic tests in vivax malaria.Y

Evaluation of Touch and Durability of Cotton Knit Fabrics Treated with Reactive Urethane-Silicone Softener

A new reactive urethane–silicone softener was developed to provide a soft touch to cotton knit fabrics with improved durability to washing and dimensional stability. The reactive urethane–silicone softener consisted of an amino silicone softener and a blocked isocyanate, which can crosslink and react with cellulose surfaces. The activated isocyanate from the blocked isocyanate reacted with the amino silicone softener by heat treatment at 150 °C for 30 min. The mechanical properties of the cotton knit fabrics treated with the urethane–silicone softener were evaluated using a Kawabata Evaluation System-Fabrics (KES-FB) system. The cotton knit fabrics treated with the urethane–silicone softener showed excellent elasticity, flexibility and shear recovery as well as excellent recovery against bending deformation, and soft and smooth surface characteristics with a small coefficient of friction that were maintained even after washing 20 times