Weather conditions may have an impact on SARS-CoV-2 virus transmission, as has been shown for seasonal influenza. Virus transmission most likely favors low temperature and low humidity conditions. This systematic review aimed to collect evidence on the impact of temperature and humidity on COVID-19 mortality. This review was registered with PROSPERO (registration no. CRD42020196055). We searched the Pubmed, Embase, and Cochrane COVID-19 databases for observational epidemiological studies. Two independent reviewers screened the title/abstracts and full texts of the studies. Two reviewers also performed data extraction and quality assessment. From 5051 identified studies, 11 were included in the review. Although the results were inconsistent, most studies imply that a decrease in temperature and humidity contributes to an increase in mortality. To establish the association with greater certainty, future studies should consider accurate exposure measurements and important covariates, such as government lockdowns and population density, sufficient lag times, and non-linear associations.

Background: Potentially modifiable lifestyle and psychological factors may influence Alzheimer’s disease (AD)-related brain pathology and cognitive function, thereby influencing cognitive resilience in late life. Objective: This cross-sectional study investigated associations and pathways between lifestyle and psychological factors related to cognitive reserve and psychological debt, AD-related biomarkers, and cognitive function, as well as potential differences in these associations between AD risk groups. Methods: In total, 298 non-demented older adults (mean age = 69.5 years, 44% women) of the DELCODE study were included. Structural equation modeling was used to assess the associations between the constructs of cognitive reserve (education, occupational complexity, leisure activity participation) and psychological debt (depression and anxiety symptoms, neuroticism, sleep quality), manifest AD-related biomarkers (cerebrospinal fluid [CSF] amyloid-beta [Aβ] 42, splenial white matter hyperintensities [WMH], hippocampal volume), and latent cognitive function of increased AD risk (Preclinical Alzheimer’s Cognitive Composite [PACC]). In the structural equation model, biomarkers were transformed such that higher values indicated greater AD-related brain pathology and age was included as a covariate. Multigroup analyses assessed moderations by established AD risk modifiers, namely sex and apolipoprotein ε4 (APOE ε4) genotype. Results: In the total sample, higher cognitive reserve was associated with better cognitive function ( p = .005), independent of AD-related biomarkers. Higher cognitive reserve was associated with lower psychological debt ( p = .035); however, neither construct showed a significant association with the AD-related biomarkers ( p ≥ .177). AD-related biomarkers of CSF Aβ42 ( p = .021), splenial WMH ( p = .044), and hippocampal neurodegeneration ( p = .007) were each independently associated with lower cognitive function. Most associations were comparable between AD risk groups stratified by sex and APOE ε4 genotype. The relationships between cognitive reserve and psychological debt, and between CSF Aβ42 and splenial WMH were stronger in APOE ε4 non-carriers than in carriers (all p ≤ .020). Conclusions: Cognitive reserve emerges as a key resilience pathway, supporting late-life cognition independently of AD-related pathology, with largely consistent effects across AD risk groups. The role of psychological debt warrants longitudinal investigation, particularly in vulnerable older populations. Trial registration: German Clinical Trials Register: DRKS00007966, Registered: 4 May 2015.

Background: This study examines the relationship between occupation and sickness presenteeism (SP) among German employees. In addition, it investigates occupation-specific differences in SP according to supervisory or managerial responsibilities. Methods: A total of 86,855 employees (average age: 45.7 ± 10.5, 48.3% men, and 51.7% women) from the German National Cohort (NAKO) who had reported illness at least once in the past 12 months were included in this cross-sectional study (response: 15.6%). Data were collected between 2014 and 2019. Occupations were grouped into 14 segments based on the German Classification of Occupations 2010. SP was defined as attending work despite illness at least once within the past 12 months. Robust Poisson regression analyses were conducted to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) for SP, comparing each occupational segment with all other occupations combined as the reference group. Additional analyses compared SP between employees with and without supervisory or managerial responsibilities overall and within each occupational segment, and by sex. Results: Among employees who had been ill at least once in the past 12 months, 76.4% reported SP. The highest prevalence of SP was observed in healthcare, social and cultural service occupations, trade, and food industry and hospitality. Overall, employees with supervisory or managerial responsibilities had a higher SP prevalence than those without such responsibilities (PR = 1.08; 95% CI = 1.07–1.10). This association was stronger among men (PR = 1.11; 95% CI = 1.09–1.12) than among women (PR = 1.04; 95% CI = 1.02–1.06). In general, the elevated prevalence of SP among supervisors and managers was not confined to specific occupational segments. Rather, certain occupational segments exhibited consistently higher SP prevalence regardless of hierarchical position. Conclusions: Among German employees, SP prevalence varies notably across occupations, with above-average levels in healthcare, social and cultural service, trade, and food industry and hospitality. Supervisory and managerial responsibilities were associated with a modestly higher prevalence of SP, with a stronger association among men than women. However, occupation-specific patterns were broadly similar across hierarchical groups, indicating that SP is likely influenced by a combination of occupational context and hierarchical position.

(1) Background: Compared to medical personnel, SARS-CoV-2mRNA vaccination-related positive immunity rates, levels, and preservation over time in dialysis and kidney transplant patients are reduced. We hypothesized that COVID-19 pre-exposure influences both vaccination-dependent immunity development and preservation in a group-dependent manner. (2) Methods: We evaluated 2- and 9-month follow-up data in our observational Dia-Vacc study, exploring specific cellular (interferon-γ release assay = IGRA) and/or humoral immune responses (IgA/IgG/RBD antibodies) after two SARS-CoV-2mRNA vaccinations in 2630 participants, including medical personnel (301-MP), dialysis patients (1841-DP), and kidney transplant recipients (488-KTR). Study participants were also separated into COVID-19 pre-exposure (hybrid immunity) positive (n = 407) versus negative (n = 2223) groups. (3) Results: COVID-19 pre-exposure improved most vaccination-related positive immunity rates in KTR and DP at 2 months but not in MP, where rates reached almost 100% independent of hybrid immunity. In the COVID-19-negative study, patients’ immunity faded between two and nine months, evaluated via the percentage of patients with an RBD antibody decrease >50%, and was markedly group- (MP-17.8%, DP-52.2%, and KTR-38.6%) and vaccine type-dependent. In contrast, in all patient groups with COVID-19, pre-exposure RBD antibody decreases of >50% were similarly rare (MP-4.3%, DP-7.2%, and KTR-0%) but still vaccine type-dependent, with numerically reduced numbers in mRNA-1273- versus BNT162b2mRNA-treated patients. Multivariable regression analysis of RBD antibody changes between two and nine months by interval scale categorization confirmed COVID-19 pre-exposure as a factor in inhibiting strong RBD Ab fading. COVID-19 pre-exposure in MP and DP also numerically reduced T-cell immunity fading. In DP, symptomatic (versus asymptomatic) COVID-19 pre-exposure was identified as a factor in reducing strong RBD Ab fading after vaccination. (4) Conclusions: After mRNA vaccination, immunity positivity rates in DP and KTR but not MP, as well as immunity preservation in MP/DP/KTR, are markedly improved via prior COVID-19 infection. In DP, prior symptomatic compared to asymptomatic COVID-19 disease was particularly effective in blocking immunity fading after mRNA vaccination.