Persistent humoral and CD4+ TH cell immunity after mild SARS-COV-2 infection-The CoNAN long-term study.

Understanding persistent cellular and humoral immune responses to SARS-CoV-2 will be of major importance to terminate the ongoing pandemic. Here, we assessed long-term immunity in individuals with mild COVID-19 up to 1 year after a localized SARS-CoV-2 outbreak. CoNAN was a longitudinal population-based cohort study performed 1.5 months, 6 months, and 12 months after a SARS-CoV-2 outbreak in a rural German community. We performed a time series of five different IgG immunoassays assessing SARS-CoV-2 antibody responses on serum samples from individuals that had been tested positive after a SARS-CoV-2 outbreak and in control individuals who had a negative PCR result. These analyses were complemented with the determination of spike-antigen specific TH cell responses in the same individuals. All infected participants were presented as asymptomatic or mild cases. Participants initially tested positive for SARS-CoV-2 infection either with PCR, antibody testing, or both had a rapid initial decline in the serum antibody levels in all serological tests but showed a persisting TH cell immunity as assessed by the detection of SARS-CoV-2 specificity of TH cells for up to 1 year after infection. Our data support the notion of a persistent T-cell immunity in mild and asymptomatic cases of SARS-CoV-2 up to 1 year after infection. We show that antibody titers decline over 1 year, but considering several test results, complete seroreversion is rare. Trial registration: German Clinical Trials Register DRKS00022416.

Non-patient-related SARS-CoV-2 exposure from colleagues and household members poses the highest infection risk for hospital employees in a German university hospital: follow-up of the prospective Co-HCW seroprevalence study.

PURPOSE: The Co-HCW study is a prospective, longitudinal, single-center observational study that aims to assess the SARS-CoV-2 seroprevalence and infection status in staff members of Jena University Hospital (JUH) in Jena, Germany. METHODS: This follow-up study covers the observation period from 19th May 2020 to 22nd June 2021. At each of the three voluntary study visits, participants filled out a questionnaire regarding their SARS-CoV-2 exposure and provided serum samples to detect specific SARS-CoV-2 antibodies. Participants who were tested positive for antibodies against nucleocapsid and/or spike protein without previous vaccination and/or reported a positive SARS-CoV-2 PCR test were regarded to have been infected with SARS-CoV-2. Multivariable logistic regression modeling was applied to identify potential risk factors for infected compared to non-infected participants. RESULTS: Out of 660 participants that were included during the first study visit, 406 participants (61.5%) were eligible for the final analysis as their COVID-19 risk area (high-risk n = 76; intermediate-risk n = 198; low-risk n = 132) did not change during the study. Forty-four participants [10.8%, 95% confidence interval (95%CI) 8.0-14.3%] had evidence of a current or past SARS-CoV-2 infection detected by serology (n = 40) and/or PCR (n = 28). No association between SARS-CoV-2 infection and the COVID-19 risk group according to working place was detected. However, exposure to a SARS-CoV-2 positive household member [adjusted OR (AOR) 4.46, 95% CI 2.06-9.65] or colleague (AOR 2.30, 95%CI 1.10-4.79) was found to significantly increase the risk of a SARS-CoV-2 infection. CONCLUSION: Our results demonstrate that non-patient-related SARS-CoV-2 exposure posed the highest infection risk for hospital staff members of JUH.

Identification of cardiovascular and molecular prognostic factors for the morbidity and mortality in COVID-19-sepsis (ICROVID): Protocol for a prospective multi-centre cohort study.

INTRODUCTION: Severe COVID-19 constitutes a form of viral sepsis. Part of the specific pathophysiological pattern of this condition is the occurrence of cardiovascular events. These include pulmonary embolism, arrhythmias and cardiomyopathy as manifestations of extra-pulmonary organ dysfunction. Hitherto, the prognostic impact of these cardiovascular events and their predisposing risk factors remains unclear. This study aims to explore this question in two cohorts of viral sepsis-COVID-19 and influenza-in order to identify new theragnostic strategies to improve the short- and long-term outcome of these two diseases. METHODS AND ANALYSIS: In this prospective multi-centre cohort study, clinical assessment will take place during the acute and post-acute phase of sepsis and be complemented by molecular laboratory analyses. Specifically, echocardiography and cardiovascular risk factor documentation will be performed during the first two weeks after sepsis onset. Aside from routine haematological and biochemical laboratory tests, molecular phenotyping will comprise analyses of the metabolome, lipidome and immune status. The primary endpoint of this study is the difference in 3-month mortality of patients with and without septic cardiomyopathy in COVID-19 sepsis. Patients will be followed up until 6 months after onset of sepsis via telephone interviews and questionnaires. The results will be compared with a cohort of patients with influenza sepsis as well as previous cohorts of patients with bacterial sepsis and healthy controls. ETHICS AND DISSEMINATION: Approval was obtained from the Ethics Committee of the Friedrich Schiller University Jena (2020-2052-BO). The results will be published in peer-reviewed journals and presented at appropriate conferences. TRIAL REGISTRATION: DRKS00024162.

Comparison of fatigue, cognitive dysfunction and psychological disorders in post-COVID patients and patients after sepsis: is there a specific constellation?

BACKGROUND: Sequelae of COVID-19 can be severe and longlasting. We compared frequencies of fatigue, depression and cognitive dysfunction in survivors of SARS-CoV-2-infection and sepsis. METHODS: We performed a prospective cohort study of 355 symptomatic post-COVID patients who visited our out-patient clinic for post-COVID-19 care. We compared them with 272 symptomatic patients from the Mid-German Sepsis Cohort, which investigates the long-term courses of sepsis survivors. Possible predictors for frequent clinical findings (fatigue, signs of depression, cognitive dysfunction) in post-COVID were investigated with multivariable logistic regression. RESULTS: Median age of the post-COVID patients was 51 years (range 17-86), 60.0% were female, and 31.8% required hospitalization during acute COVID-19. In the post-COVID patients (median follow-up time: 163 days) and the post-sepsis patients (180 days), fatigue was found in 93.2% and 67.8%, signs of depression were found in 81.3% and 10.9%, and cognitive dysfunction was found in 23.5% and 21.3%, respectively. In post-COVID, we did not observe an association between fatigue or depression and the severity of acute COVID-19. In contrast, cognitive dysfunction was associated with hospitalization (out-patient versus in-patient) and more frequent in post-COVID patients treated on an ICU compared to the MSC patients. CONCLUSION: In post-COVID patients, fatigue and signs of depression are more common than in sepsis survivors, independent from the acute SARS-CoV-2-infection. In contrast, cognitive dysfunction is associated with hospitalization. Despite the differences in frequencies, owing to the similarity of post-COVID and post-sepsis sequelae, this knowledge may help in implementing follow-up approaches after SARS-CoV-2 infection.

The role of risk communication in public health interventions. An analysis of risk communication for a community quarantine in Germany to curb the SARS-CoV-2 pandemic.

BACKGROUND: Separating ill or possibly infectious people from their healthy community is one of the core principles of non-pharmaceutical interventions. However, there is scarce evidence on how to successfully implement quarantine orders. We investigated a community quarantine for an entire village in Germany (Neustadt am Rennsteig, March 2020) with the aim of better understanding the successful implementation of quarantine measures. METHODS: This cross-sectional survey was conducted in Neustadt am Rennsteig six weeks after the end of a 14-day mandatory community quarantine. The sample size consisted of 562 adults (64% of the community), and the response rate was 295 adults, or 52% (33% of the community). FINDINGS: National television was reported as the most important channel of information. Contact with local authorities was very limited, and partners or spouses played a more important role in sharing information. Generally, the self-reported information level was judged to be good (211/289 [73.0%]). The majority of participants (212/289 [73.4%]) approved of the quarantine, and the reported compliance was 217/289 (75.1%). A self-reported higher level of concern as well as a higher level of information correlated positively with both a greater acceptance of quarantine and self-reported compliant behaviour. INTERPRETATION: The community quarantine presented a rare opportunity to investigate a public health intervention for an entire community. In order to improve the implementation of public health interventions, public health risk communication activities should be intensified to increase both the information level (potentially leading to better compliance with community quarantine) and the communication level (to facilitate rapport and trust between public health authorities and their communities).

Bridging animal and clinical research during SARS-CoV-2 pandemic: A new-old challenge.

Many milestones in medical history rest on animal modeling of human diseases. The SARS-CoV-2 pandemic has evoked a tremendous investigative effort primarily centered on clinical studies. However, several animal SARS-CoV-2/COVID-19 models have been developed and pre-clinical findings aimed at supporting clinical evidence rapidly emerge. In this review, we characterize the existing animal models exposing their relevance and limitations as well as outline their utility in COVID-19 drug and vaccine development. Concurrently, we summarize the status of clinical trial research and discuss the novel tactics utilized in the largest multi-center trials aiming to accelerate generation of reliable results that may subsequently shape COVID-19 clinical treatment practices. We also highlight areas of improvement for animal studies in order to elevate their translational utility. In pandemics, to optimize the use of strained resources in a short time-frame, optimizing and strengthening the synergy between the preclinical and clinical domains is pivotal.

Prospective surveillance study in a 1,400-bed university hospital: COVID-19 exposure at home was the main risk factor for SARS-CoV-2 point seroprevalence among hospital staff.

The Co-HCW study is a prospective cohort study among hospital staff, including healthcare workers (HCWs) and administration staff, at the Jena University Hospital (JUH), Germany. The objectives of this study were to assess SARS-CoV-2 IgG seroprevalence, individual exposure risk factors and compliance of HCWs to wear personal protective equipment (PPE). After the first nosocomial COVID-19 outbreak at JUH, mandatory masking was implemented on 20th March 2020. We evaluated point seroprevalence using two IgG detecting immunoassays and issued a questionnaire to assess COVID-19 exposure, clinical symptoms and compliance to wear PPE. Antibody retesting was offered to participants with a divergent result of both immunoassays 5-10 weeks after the first test. Between 19th May and 19th June 2020, we analysed 660 participants [out of 3,228; 20.4%]. Among them, 212 participants (32.1%) had received a previous COVID-19 test. Four of them (1.9%) reported a positive test result. After recruitment, 18 participants (2.7%) had SARS-CoV-2 antibodies in at least one immunoassay. Overall, 21 participants (3.2%) had any evidence of a past or current SARS-CoV-2 infection. Among them, 13 (61.9%) were not aware of direct COVID-19 exposure and 9 (42.9%) did not report any clinical symptoms. COVID-19 exposure at home (adjusted OR (aOR) with 95% CI: 47.82 (5.49, 416.62)) was associated with SARS-CoV-2 seroprevalence. We observed no evidence for an association between seroprevalence and exposure at work (aOR 0.48 (0.13, 1.70)) or with COVID-19 risk area according to the working place (aOR for intermediate-risk vs. high-risk: 1.97 (0.42, 9.22), aOR for low-risk versus high-risk: 2.10 (0.40, 11.06); p = .655). Reported compliance of HCWs to wear PPE differed (p < .001) between working in high-risk (98.3%) and in intermediate-risk areas (69.8%). In conclusion, compared to administration staff, we observed no additional risk to acquire SARS-CoV-2 infections by patient care, probably due to high compliance to wear PPE.

Antibody response using six different serological assays in a completely PCR-tested community after a coronavirus disease 2019 outbreak-the CoNAN study.

OBJECTIVES: Due to a substantial proportion of asymptomatic and mild courses, many severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections remain unreported. Therefore, assessment of seroprevalence may detect the real burden of disease. We aimed to determine and characterize the rate of SARS-CoV-2 infections and the resulting seroprevalence in a defined population. The primary objective of the study was to assess SARS-CoV-2 antibody seroprevalence using six different IgG-detecting immunoassays. Secondary objectives of the study were: (a) to determine potential risk factors for symptomatic versus asymptomatic coronavirus disease 2019 courses, and (b) to investigate the rate of virus RNA-persistence. METHODS: CoNAN is a population-based cohort study performed in the community Neustadt am Rennsteig, Germany, which was quarantined from 22 March to 5 April after six SARS-CoV-2 cases were detected in the village's population. The SARS-CoV-2 outbreak comprised 51 cases and 3 deaths. The CoNAN study was performed from 13 May to 22 May 2020, 6 weeks after a SARS-CoV-2 outbreak. RESULTS: We enrolled a total of 626 participants (71% of the community population) for PCR and antibody testing in the study. All actual SARS-CoV-2 PCR tests were negative. Fifty-two out of 620 (8.4%) participants had antibodies against SARS-CoV-2 in at least two different assays. There were 38 participants with previously PCR-confirmed SARS-CoV-2 infection. Of those, only 19 (50%) displayed anti-SARS-CoV-2 antibodies. We also show that antibody-positive participants with symptoms compatible with a respiratory tract infection had significantly higher antibody levels then asymptomatic participants (EU-assay: median 2.9 versus 7.2 IgG-index, p 0.002; DS-assay: median 45.2 versus 143 AU/mL, p 0.002). Persisting viral replication was not detected. CONCLUSIONS: Our data question the relevance and reliability of IgG antibody testing to detect past SARS-CoV-2 infections 6 weeks after an outbreak. We conclude that assessing immunity for SARS-CoV-2 infection should not rely on antibody tests alone.

[Period Prevalence of SARS-CoV-2 in an Unselected Sample of Pregnant Women in Jena, Thuringia]. / Periodenprävalenz von SARS-CoV-2 in einer unselektierten Stichprobe schwangerer Frauen in Jena, Thüringen.

INTRODUCTION: Following an exponential increase in SARS-CoV-2 infections, the city of Jena, Thuringia, was the first in Germany to introduce mandatory mouth and nose coverings. An estimation of the SARS-CoV-2 period prevalence was achieved by screening an unselected cohort of pregnant women. Of interest was the number of unreported cases. METHODS: Upon admission to hospital, patients were screened for SARS-CoV-2 by a specific real-time PCR and antibodies determined by a specific SARS-CoV-2 IgG in serum by ELISA. The SARS-CoV-2 period prevalence was estimated using the Clopper-Pearson exact method, the group comparison with Fischer's exact test. RESULTS: From 6 April to 13 May 2020, 234 pregnant women were admitted to the Department of Obstetrics. A total of 225 (96.2%) SARS-CoV-2 PCRs were carried out and all remained negative. Specific IgG antibodies were detected in one (0.6%) of 180 (76.9%) antibody tests performed. The interval estimate of the period prevalence thus results in a 95% confidence interval between 0-1.7%. For 96 households with children, the period prevalence is 0-3.8%, which does not differ from the 0-4.8% for 76 households without children (p=1.00). DISCUSSION: This is the first report on the SARS-CoV-2 period prevalence of an unselected sample of pregnant women in Germany. Antibody testing showed no evidence of the feared high number of unreported asymptomatic SARS-CoV-2 infections. The seroconversion rate was below 1% (0.6%).