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BackgroundWe chronicle SARS-CoV-2 sero-prevalence through eight cross-sectional sero-surveys (snapshots) in the Lower Mainland (Greater Vancouver and Fraser Valley), British Columbia, Canada from March 2020 to August 2022. MethodsAnonymized-residual sera were obtained from children and adults attending an outpatient laboratory network. Sera were tested with at least three immuno-assays per snapshot to detect spike (S1) and/or nucleocapsid protein (NP) antibodies. Sero-prevalence was defined by dual-assay positivity, including any or infection-induced, the latter requiring S1+NP antibody detection from January 2021 owing to vaccine availability. Infection-induced estimates were used to assess the extent to which surveillance case reports under-estimated infections. ResultsSero-prevalence was [≤]1% by the 3rd snapshot in September 2020 and <5% by January 2021 (4th). Following vaccine roll-out, sero-prevalence increased to >55% by May/June 2021 (5th), [~]80% by September/October 2021 (6th), and >95% by March 2022 (7th). In all age groups, infection-induced sero-prevalence remained <15% through September/October 2021, increasing through subsequent Omicron waves to [~]40% by March 2022 (7th) and [~]60% by July/August 2022 (8th). By August 2022, at least 70-80% of children [≤]19 years, 60-70% of adults 20-59 years, but [~]40% of adults [≥]60 years had been infected. Surveillance case reports under-estimated infections by 12-fold between the 6th-7th and 92-fold between the 7th-8th snapshots. InterpretationBy August 2022, most children and adults had acquired SARS-CoV-2 vaccine and infection exposures, resulting in more robust hybrid immunity. Conversely the elderly, still at greatest risk of severe outcomes, remain largely-dependent on vaccine-induced protection alone, and should be prioritized for additional doses.
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Background and ObjectivesTwo- and three-dose BNT162b2 (Pfizer-BioNTech) mRNA vaccine effectiveness (VE) against SARS-CoV-2 infection, including Delta and Omicron variants, was assessed among adolescents in two Canadian provinces where first and second doses were spaced longer than the manufacturer-specified 3-week interval. MethodsTest-negative design estimated VE against laboratory-confirmed SARS-CoV-2 infection among 12-17-year-olds in Quebec and British Columbia, Canada between September 5, 2021 (epi-week 36), and April 30, 2022 (epi-week 17). Delta-dominant and Omicron-dominant periods spanned epi-weeks 36-47 and 51-17, respectively. VE was assessed from 14 days and explored by interval between first and second doses, time since second dose, and with administration of a third dose. ResultsMedian first-second dosing-interval was [~]8 weeks and second-third dosing-interval was [~]29-31 weeks. Median follow-up post-second dose was [~]10-11 weeks for Delta-dominant and [~]21-22 weeks for Omicron-dominant periods, and [~]2-7 weeks post-third dose. VE against Delta was [≥]90% to at least the 5th month post-second dose. VE against Omicron declined from [~]65-75% at 2-3 weeks to [≤]50% by the 3rd month post-vaccination, restored to [~]65% shortly following a third dose. VE exceeded 90% against Delta regardless of dosing-interval but appeared improved against Omicron with [≥]8 weeks between first and second doses. ConclusionIn adolescents, two BNT162b2 doses provided strong and sustained protection against Delta but reduced and rapidly-waning VE against Omicron. Longer interval between first and second doses and a third dose improved Omicron protection. Updated vaccine antigens, increased doses and/or dosing-intervals may be needed to improve adolescent VE against immunological-escape variants.
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IntroductionIn randomized controlled trials, single-dose efficacy against SARS-CoV-2 illness exceeded 90% for mRNA vaccines (BNT162b2 and mRNA-1273), and 75% for ChAdOx1. In British Columbia (BC), Canada second doses were deferred up to 16 weeks and ChAdOx1 was only initially recommended for adults 55 years of age and older. We compared single-dose vaccine effectiveness (VE) during the spring 2021 wave in BC when Alpha and Gamma variants of concern (VOC) predominated. MethodsVE was estimated against infection and hospitalization by test-negative design: cases were RT-PCR test-positive for SARS-CoV-2 and controls were test-negative. Adults 50-69 years old with specimen collection between April 4 and May 22 (weeks 14-20) were included. Variant-specific VE was estimated between weeks 17-20 when genetic characterization of all case viruses was performed, primarily through whole genome sequencing. ResultsVE analyses included 7,116 (10%) cases and 60,958 controls. Three-quarters of vaccinated participants received mRNA vaccine (60% BNT162b2, 15% mRNA-1273) and 25% received ChAdOx1. Half of genetically characterized viruses were Alpha, with 38% Gamma, 4% Delta and 8% non-VOCs. Single-dose VE against any infection was 75% (95%CI: 72-78) for BNT162b2, 82% (95%CI: 76-87) for mRNA-1273 and 61% (95%CI: 54-66) for ChAdOx1. VE against hospitalization was 83% (95%CI: 76-89), 85% (95%CI: 63-94) and 96% (95%CI: 86-99), respectively. VE against Alpha vs. Gamma infections did not differ among mRNA (78%;95%CI: 73-82 and 80%;95%CI: 74-85) or ChAdOx1 (66%;95%CI: 57-74 and 60%;95%CI: 48-69) recipients. ConclusionsA single dose of mRNA vaccine reduced the SARS-CoV-2 infection risk by at least 75%, including infections due to early VOC. Although effectiveness of a single dose of ChAdOx1 was lower at 60% against infection, just one dose of any vaccine reduced the hospitalization risk by more than 80%. In the context of constrained vaccine supplies, these findings have implications for global vaccine deployment to reduce the overall burden of infections and hospitalizations due to SARS-CoV-2.
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Sleep disorders, increasingly prevalent in the general population, induce impairment in daytime functioning and other clinical problems. As changes in cortical excitability have been reported as potential pathophysiological mechanisms underlying sleep disorders, multiple studies have explored clinical effects of modulating cortical excitability through non-invasive brain stimulation in treating sleep disorders. In this study, we critically reviewed clinical studies using non-invasive brain stimulation, particularly transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), for treatment of sleep disorders. Previous studies have reported inconsistent therapeutic effects of TMS and tDCS for various kinds of sleep disorders. Specifically, low-frequency repetitive TMS (rTMS) and cathodal tDCS, both of which exert an inhibitory effect on cortical excitability, have shown inconsistent therapeutic effects for insomnia. On the other hand, high-frequency rTMS and anodal tDCS, both of which facilitate cortical excitability, have improved the symptoms of hypersomnia. In studies of restless legs syndrome, high-frequency rTMS and anodal tDCS induced inconsistent therapeutic effects. Single TMS and rTMS have shown differential therapeutic effects for obstructive sleep apnea. These inconsistent findings indicate that the distinctive characteristics of each non-invasive brain stimulation method and specific pathophysiological mechanisms underlying particular sleep disorders should be considered in an integrated manner for treatment of various sleep disorders. Future studies are needed to provide optimized TMS and tDCS protocols for each sleep disorder, considering distinctive effects of non-invasive brain stimulation and pathophysiology of each sleep disorder.
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Suicide is a leading cause of death worldwide, especially among adolescents and young adults. Considering this fact, it is imperative that we understand the neural mechanisms underlying suicidal thoughts and behaviors in youth from a neurodevelopmental perspective. In this review, we focused on the magnetic resonance imaging studies that examined the neural correlates of suicidal ideations (SI) or attempts (SA) in youth. We reviewed twenty-three cross-sectional studies reporting the structural and functional alterations in association with SI or SA among adolescents and young adults with various mental disorders. The previous literature suggests that the dorsolateral prefrontal cortex, anterior cingulate cortex, and ventral frontolimbic circuit, may play an important role in the pathophysiology of suicidal behavior in youth through altered top-down control over emotion and impulsivity. Future studies with a longitudinal design and using multimodal imaging techniques may be of help to identify novel therapeutic targets specific for youth with suicidal thoughts and behaviors.
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Transcranial direct current stimulation (tDCS) is a non-invasive and effective neuromodulatory technique to modulate cortical activities by applying 1 to 2 milliamps electric current. The use of tDCS to enhance cognitive function such as executive function and memory has attracted much attention in recent years, and a lot of studies have been carried out to identify neural mechanisms underlying cognitive enhancement effects of tDCS. In this review, we discussed the previous neuroimaging studies on applications of tDCS for cognitive enhancement using functional magnetic resonance imaging (fMRI). Previous tDCS studies for neurological or psychiatric conditions and elderly individuals suggested that cognitive enhancement effects of tDCS were associated with normalizing aberrant brain networks and activities related to pathophysiology. Moreover, tDCS-induced cognitive enhancement in healthy individuals was associated with functional changes in brain activations and network connectivity. Furthermore, cognitive enhancement effects of tDCS were varied depending on the neurological structure and functional characteristics between individuals. The current review may provide critical insights into functional activity and connectivity of the brain regarding cognitive enhancement effects of tDCS, which could give direction for further studies on identifying the specific neural mechanisms and clinical strategies of tDCS.
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BACKGROUND: The prevalence of metabolic syndrome (MetS) has risen rapidly worldwide, including in South Korea. Factors related to lifestyle are closely associated with the development of MetS. The aim of this study was to investigate the association between MetS and a number of factors positively influencing health, namely non-smoking, low-risk drinking, sufficient sleep, regular exercise, and the habit of reading food labels, among Korean men. METHODS: This cross-sectional study included 3,869 men from the 2007–2009 Korean National Health and Nutrition Examination Survey. Information on five factors positively influencing their health was obtained using a self-reported questionnaire. We categorized subjects into four groups, depending on the number of positive factors reported (group I, 0–1 factor; group II, 2 factors; group III, 3 factors; group IV, 4–5 factors). RESULTS: Men who reported a greater number of positive health factors had better laboratory and anthropometric values than men who reported fewer positive health factors. The prevalence of MetS was 29.1, 27.2, 20.7, and 14.6% in groups I to IV, respectively. Compared to group I, odds ratios (95% confidence intervals) for MetS were 0.96 (0.78–1.19) in group II, 0.67 (0.52–0.87) in group III, and 0.52 (0.35–0.76) in group IV, after adjusting for confounding factors. Odds ratios for abdominal obesity, glucose intolerance, and hypertriglyceridemia were statistically significant. CONCLUSION: A greater number of positive lifestyle factors influencing health were associated with a lower risk of developing MetS, in a nationally representative sample of Korean men.
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Humans , Male , Alcohol Drinking , Cross-Sectional Studies , Drinking , Glucose Intolerance , Hypertriglyceridemia , Korea , Life Style , Metabolic Syndrome , Nutrition Surveys , Obesity, Abdominal , Odds Ratio , Prevalence , SmokingABSTRACT
PURPOSE: Sex hormone-binding globulin (SHBG) is a serum glycoprotein produced predominantly in hepatocytes. As such, the synthesis of SHBG could be associated with liver function and metabolic syndrome. Alanine aminotransferase (ALT) levels could reflect hepatocellular injury and insulin resistance; however, the relationship between hepatic steatosis and ALT with SHBG has not been investigated in humans. The objective of this study was to investigate the associations between SHBG and hepatocyte damage among Korean male patients with hepatic steatosis enrolled in a health examination program. MATERIALS AND METHODS: We performed a retrospective cross-sectional study with 922 participants who underwent routine health examinations. A total of 922 men with or without hepatic steatosis were divided into three groups. We analyzed the risk of lower serum SHBG levels with or without elevated serum ALT levels using odds ratios with 95% confidence intervals (CIs). RESULTS: A significantly increased risk of lower serum SHBG level was observed in the group with hepatic steatosis and ALT elevation (95% CI 1.591–4.681). CONCLUSION: In men with hepatic steatosis, we found that elevated serum ALT levels were associated with lower serum SHBG levels. This finding suggests that subjects with both hepatic steatosis and increased ALT should be considered to have low levels of SHBG.
