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With newly rising coronavirus disease 2019 (COVID-19) cases, important data gaps remain on (i) long-term dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rates in fixed cohorts (ii) identification of risk factors, and (iii) establishment of effective surveillance strategies. By polymerase chain reaction and antibody testing of 1% of the local population and >90,000 app-based datasets, the present study surveilled a catchment area of 300,000 inhabitants from March 2020 to February 2021. Cohort (56% female; mean age, 45.6 years) retention was 75 to 98%. Increased risk for seropositivity was detected in several high-exposure groups, especially nurses. Unreported infections dropped from 92 to 29% during the study. “Contact to COVID-19–affected” was the strongest risk factor, whereas public transportation, having children in school, or tourism did not affect infection rates. With the first SARS-CoV-2 cohort study, we provide a transferable model for effective surveillance, enabling monitoring of reinfection rates and increased preparedness for future pandemics.

BackgroundMore than one year into the COVID-19 pandemic, important data gaps remain on longitudinal prevalence of SARS-CoV-2 infection at the population level and in defined risk groups, efficacy of specific lockdown measures, and on (cost-)effective surveillance.MethodsThe ELISA (LübeckLongitudinalInvestigation ofSARS-CoV-2 Infection) study invited adult inhabitants (n=∼300,000) from the Lübeck area (Northern Germany) and enrolled 3051 participants (∼1%); 1929 population-matched and 1645 with high-exposure based on profession. The one-year study period (03/2020-02/2021) spanned massive influx of tourism in the summer, rise of infection rates in the fall/winter 2020/2021, and two lockdowns. Participants were screened seven times for SARS-CoV-2 infection using PCR and antibody testing and monitored with an app-based questionnaire (n=∼91,000).ResultsCohort (56% female; mean age: 45.6 years) retention was 75%-98%; 89 persons (3.5%) were antibody- and/or PCR-positive. Seropositivity was almost 2-fold higher in men and increased risk detected in several high-exposure groups (highest for nurses, followed by police, army, firemen, and students). In May 2020, 92% of the infections were missed by PCR testing; by February 2021, only 29% remained undiagnosed. “Contact to COVID-19-affected” was the most relevant risk factor. Other factors, such as frequent use of public transportation, shopping, close contacts at work, and extensive tourism in the summer did not impact infection rates.ConclusionsWe i) provide a model for effective, regional surveillance; ii) identify infection risk factors informing public health measures; iii) demonstrate that easing of lockdown measures appears safe at times of low prevalence in the presence of continuous monitoring.

To treat the SARS-CoV-2 virus, that enters the body through the respiratory tract, different vaccines in particular against the SARS-CoV-2 spike (S)-protein have been developed or are in the development process. For the BioNTech / Pfizer mRNA vaccine BNT162b2, which is injected twice, protection against COVID-19 has been described for the first weeks after the second vaccination. The underlying mechanisms of defense and the long-term effectiveness of this vaccine against COVID-19 are currently under investigation.In addition to the induction of systemic antibodies (Abs), Ab responses in the respiratory tract would help to form a first line of defense against SARS-CoV-2. Furthermore, protection depends on Fab-part-dependent neutralizing capacities, however, Fc-part-mediated effector mechanisms might also be important. Long-term defense would be based on the induction of long-lived antibody-producing plasma cells (PCs) and memory B cells.Here, we established different assays to analyze anti-SARS-CoV-2-S IgG and IgA Abs in blood serum and saliva as well as SARS-CoV-2-S1-reactive IgG and IgA PCs and potential memory B cells in the blood of individuals upon their first immunization with BNT162b2.We show that the vaccine induces in particular anti-SARS-CoV-2-S IgG1 and IgG3 as well as IgA1 and in some individuals also IgG2 and IgA2 serum Abs. In the saliva, we found no anti-SARS-CoV-2-S IgA, but instead IgG Abs. Furthermore, we found SARS-CoV-2-S reactive IgG+ blood PCs and potential memory B cells as well as SARS-CoV-2-S reactive IgA+ PCs and/or potential memory B cells in some individuals.Our data suggest that the vaccine induces a promising CD4+ T cell-dependent systemic IgG1 and IgG3 Ab response with IgG+ PCs and potential memory B cells. In addition to the systemic IgG response, the systemic IgA and saliva IgG response might help to improve a first line of defense in the respiratory tract against SARS-CoV-2 and its mutants.

Coronavirus disease 2019 (COVID-19) is a viral infection affecting multiple organ systems of great significance for metabolic processes. Thus. there is increasing interest in metabolic and lipoprotein signatures of the disease and early analyses have demonstrated metabolic pattern typical for atherosclerotic and hepatic damage in COVID-19 patients. However, it remains unclear whether these are specific for COVID-19 or a general marker of critical illness. To answer this question, we have analyzed 276 serum samples from 92 individuals using NMR metabolomics, including longitudinally collected samples from 5 COVID-19 and 11 cardiogenic shock intensive care patients, 18 SARS-CoV-2 antibody-positive individuals, and 58 healthy controls.COVID-19 patients showed a distinct metabolic serum profile, including changes typical for severe dyslipidemia and a deeply altered metabolic status compared to healthy controls. Specifically, VLDL parameters, IDL particles, large-sized LDL particles, and the ApoB100/ApoA1 ratio were significantly increased, whereas HDL fractions were decreased. Moreover, a similarly perturbed profile was apparent, even when compared to other ICU patients suffering from cardiogenic shock, highlighting the impact of COVID-19 especially on lipid metabolism and energy status. COVID-19 patients were separated with an AUROC of 1.0 when compared to both healthy controls and cardiogenic shock patients. Anti-SARS-CoV-2 antibody-positive individuals without acute COVID-19 did not show a significantly perturbed metabolic profile compared to age- and sex-matched healthy controls, but SARS-CoV-2 antibody-titers correlated significantly with metabolic parameters, including levels of glycine, ApoA2, and small-sized LDL and HDL subfractions. Our data suggest that NMR metabolic profiles are suitable for COVID-19 patient stratification and post-treatment monitoring.

Background Musculoskeletal disorders (MSD) represent the highest cause of disability in Europe. Reduced mobility and quality of life are the consequences of cartilage and bone tissue destruction and chronic inflammation processes, driven by release of inflammatory factors including adipokines and bone destruction by osteoclasts. For the treatment of MSD primarily drugs are used. However, additional pain relieve is achieved when the patients receive low-dose radiation therapy with photons or radon spa treatment. To assess the effect of low-dose ionising radiation, we examined in vitro whether irradiation modifies the differentiation and activity of osteoclasts and affects the expression of inflammatory and bone destructive factors in adipokine stimulated synovial fibroblasts (SF). Material and methods Human SF from rheumatoid arthritis patients (RASF) and healthy donors (NSF) were pretreated with adipokines for 24 hour prior to irradiation with X-rays. Cell supernatants were collected 24 hour post-irradiation and inflammatory factors, known to contribute to the inflammation process (IL-6, IL-8, MMP-1), were measured. Human osteoclast precursor cells were X-irradiated and cultivated with M-CSF and RANKL either on bone slices or plastic for 21 days. Differentiated osteoclasts were defined as TRAP and F-actin positive with 3 or more nuclei (DAPI). TRAP activity was measured in cell supernatants. Results In vitro cultured primary NSF and RASF show an increased release of proinflammatory factors (IL-6, IL-8, MMP-1) after stimulation with adipokines. Irradiation of stimulated cells reduces the release of inflammatory factors in RASF, but not in NSF. Irradiation of osteoclast precursor cells caused an inhibition of osteoclast differentiation and changed activity of mature osteoclasts. Conclusion Synovial fibroblasts and osteoclasts play important roles in the synovial inflammation and bone degradation in arthritic joint. Our in vitro results suggest that the release of inflammatory factors in adipokine stimulated RASF and the number of osteoclasts can be reduced by low-dose X-ray irradiation, and therefore potentially inhibiting inflammation and bone destruction in the joint of patients with MSD.