Efficacy and Safety of a Booster Regimen of Ad26.COV2.S Vaccine against Covid-19 (preprint)

BackgroundDespite the availability of effective vaccines against coronavirus disease 2019 (Covid-19), the emergence of variant strains and breakthrough infections pose a challenging new reality. Booster vaccinations are needed to maintain vaccine-induced protection. MethodsENSEMBLE2 is an ongoing, randomized, double-blind, placebo-controlled, phase 3 pivotal trial including crossover vaccination after emergency authorization of Covid-19 vaccines. Adults aged [≥]18 years were randomized to receive Ad26.COV2.S or placebo as a primary dose plus a booster dose at two months. The primary endpoint was vaccine efficacy against the first occurrence of molecularly-confirmed moderate to severe-critical Covid-19 with onset [≥]14 days after booster vaccination in the per-protocol population. Key efficacy, safety, and immunogenicity endpoints were also assessed. ResultsThe double-blind phase enrolled 31,300 participants, 14,492 of whom received 2 doses and were evaluable for efficacy (per-protocol set, Ad26.COV2.S n=7484; placebo n=7008). Baseline demographics and characteristics were balanced. Vaccine efficacy was 75.2% (adjusted 95% CI, 54.6-87.3) against moderate to severe-critical Covid-19 and was similar against symptomatic infection (75.6% [55.5-99.9]). Efficacy was consistent across participants with and without comorbidities, and reached 93.7% (58.5-99.9) in the US. Vaccine efficacy against severe-critical Covid-19 was 100% (32.6-100.0; 0 vs 8 cases). The booster vaccine induced robust humoral responses and exhibited an acceptable safety profile. ConclusionsA homologous Ad26.COV2.S booster administered 2 months after primary single-dose vaccination in adults led to high vaccine efficacy, including against any symptomatic infection and SARS-CoV-2 variants prevalent during the study. (Funding: Janssen Research and Development and others; ENSEMBLE2 ClinicalTrials.gov number, NCT04614948.)

CMV seropositivity is a potential novel risk factor for severe COVID-19 in non-geriatric patients (preprint)

Background: COVID-19 has so far affected more than 250 million individuals worldwide, causing more than 5 million deaths. Several risk factors for severe disease have been identified, most of which coincide with advanced age. In younger individuals, severe COVID-19 often occurs in the absence of obvious comorbidities. Guided by the finding of cytomegalovirus (CMV)-specific T cells with some cross-reactivity to SARS-CoV-2 in a COVID-19 intensive care unit (ICU) patient, we decided to investigate whether CMV seropositivity is associated with severe or critical COVID-19. Methods: National German COVID-19 bio-sample and data banks were used to retrospectively analyze the CMV serostatus of patients who experienced mild (n=101), moderate (n=130) or severe to critical (n=80) disease by CMV IgG serology. We then investigated the relationship between disease severity and CMV serostatus via statistical models. Results: Non-geriatric patients (< 70 years) with severe COVID-19 were found to have a very high prevalence of CMV-seropositivity, while CMV status distribution in individuals with mild disease was similar to the prevalence in the German population; interestingly, this was not detectable in older patients. Prediction models support the hypothesis that the CMV serostatus might be a strong biomarker in identifying younger individuals with a higher risk of developing severe COVID-19. Conclusions: We identified CMV-seropositivity as a potential novel risk factor for severe COVID-19 in non-geriatric individuals in the studied cohorts. More mechanistic analyses as well as confirmation of similar findings in cohorts representing the currently most relevant SARS-CoV-2 variants should be performed shortly.

New susceptibility loci for severe COVID-19 by detailed GWAS analysis in European populations (preprint)

Due to the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), deepening the host genetic contribution to severe COVID-19 may further improve our understanding about underlying disease mechanisms. Here, we describe an extended GWAS meta-analysis of 3,260 COVID-19 patients with respiratory failure and 12,483 population controls from Italy, Spain, Norway and Germany, as well as hypothesis-driven targeted analysis of the human leukocyte antigen (HLA) region and chromosome Y haplotypes. We include detailed stratified analyses based on age, sex and disease severity. In addition to already established risk loci, our data identify and replicate two genome-wide significant loci at 17q21.31 and 19q13.33 associated with severe COVID-19 with respiratory failure. These associations implicate a highly pleiotropic ~0.9-Mb 17q21.31 inversion polymorphism, which affects lung function and immune and blood cell counts, and the NAPSA gene, involved in lung surfactant protein production, in COVID-19 pathogenesis.

Platelet expression and reactivity after BNT162b2 vaccine administration (preprint)

SARS-CoV-2 infection induces a coagulopathy characterized by platelet activation and a hypercoagulable state with an increased incidence of cardiovascular events. The viral spike protein S has been reported to enhance thrombosis formation, stimulate platelets to release pro-coagulant factors and promote the formation of platelet-leukocyte aggregates even in absence of the virus. Although SARS-CoV-2 vaccines induce spike protein overexpression to trigger SARS-CoV-2-specific immune protection, thrombocyte activity has not been investigated in this context. Here, we provide the first phenotypic platelet characterization of healthy human subjects undergoing BNT162b2 vaccination. Using mass cytometry, we analyzed the expression of constitutive transmembrane receptors, adhesion proteins and platelet activation markers in 12 healthy donors before and at five different timepoints within four weeks after the first BNT162b2 administration. We measured platelet reactivity by stimulating thrombocyte activation with thrombin receptor-activating peptide (TRAP). Activation marker expression (P-Selectin, LAMP-3, LAMP-1, CD40L and PAC-1) did not change after vaccination. All investigated constitutive transmembrane proteins showed similar expressions over time. Platelet reactivity was not altered after BNT162b2 administration. Activation marker expression was significantly lower compared to an independent cohort of mild symptomatic COVID-19 patients analyzed with the same platform. This study reveals that BNT162b2 administration does not alter platelet protein expression and reactivity.

Age-dependent impact of the major common genetic risk factor for COVID-19 on severity and mortality (preprint)

Background: There is considerable variability in COVID-19 outcomes amongst younger adults and some of this variation may be due to genetic predisposition. We characterized the clinical implications of the major genetic risk factor for COVID-19 severity, and its age-dependent effect, using individual-level data in a large international multi-centre consortium. Method: The major common COVID-19 genetic risk factor is a chromosome 3 locus, tagged by the marker rs10490770. We combined individual level data for 13,424 COVID-19 positive patients (N=6,689 hospitalized) from 17 cohorts in nine countries to assess the association of this genetic marker with mortality, COVID-19-related complications and laboratory values. We next examined if the magnitude of these associations varied by age and were independent from known clinical COVID-19 risk factors. Findings: We found that rs10490770 risk allele carriers experienced an increased risk of all-cause mortality (hazard ratio [HR] 1.4, 95% confidence interval [CI] 1.2-1.6) and COVID-19 related mortality (HR 1.5, 95%CI 1.3-1.8). Risk allele carriers had increased odds of several COVID-19 complications: severe respiratory failure (odds ratio [OR] 2.0, 95%CI 1.6-2.6), venous thromboembolism (OR 1.7, 95%CI 1.2-2.4), and hepatic injury (OR 1.6, 95%CI 1.2-2.0). Risk allele carriers [≤] 60 years had higher odds of death or severe respiratory failure (OR 2.6, 95%CI 1.8-3.9) compared to those > 60 years OR 1.5 (95%CI 1.3-1.9, interaction p-value=0.04). Amongst individuals [≤] 60 years who died or experienced severe respiratory COVID-19 outcome, we found that 31.8% (95%CI 27.6-36.2) were risk variant carriers, compared to 13.9% (95%CI 12.6-15.2%) of those not experiencing these outcomes. Prediction of death or severe respiratory failure among those [≤] 60 years improved when including the risk allele (AUC 0.82 vs 0.84, p=0.016) and the prediction ability of rs10490770 risk allele was similar to, or better than, most established clinical risk factors. Interpretation: The major common COVID-19 risk locus on chromosome 3 is associated with increased risks of morbidity and mortality and these are more pronounced amongst individuals [≤] 60 years. The effect on COVID-19 severity was similar to, or larger than most established risk factors, suggesting potential implications for clinical risk management. Funding: Funding was obtained by each of the participating cohorts individually.

Assessment of effective mitigation and prediction of the spread of SARS-CoV-2 in Germany using demographic information and spatial resolution (preprint)

Non-pharmaceutical interventions (NPIs) are important to mitigate the spread of infectious diseases as long as no vaccination or outstanding medical treatments are available. We assess the effectiveness of the sets of non-phar\-ma\-ceu\-ti\-cal interventions that were in place during the course of the Coronavirus disease 2019 (Covid-19) pandemic in Germany. Our results are based on hybrid models, combining SIR-type models on local scales with spatial resolution. In order to account for the age-dependence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we include realistic pre-pandemic and recently recorded contact patterns between age groups. The implementation of non-pharmaceutical interventions will occur on changed contact patterns, improved isolation, or reduced infectiousness when, e.g., wearing masks. In order to account for spatial heterogeneity, we use a graph approach and we include high-quality information on commuting activities combined with traveling information from social networks. The remaining uncertainty will be accounted for by a large number of randomized simulation runs. Based on the derived factors for the effectiveness of different non-pharmaceutical interventions over the past months, we provide different forecast scenarios for the upcoming time.

In Vitro Safety Clinical Trial of the Cardiac Liability of Hydroxychloroquine and Azithromycin as COVID19 Polytherapy (preprint)

Despite global efforts, there are no effective FDA-approved medicines for the treatment of SARS-CoV-2 infection. Potential therapeutics focus on repurposed drugs, some with cardiac liabilities. Here we report on a preclinical drug screening platform, a cardiac microphysiological system (MPS), to assess cardiotoxicity associated with hydroxychloroquine (HCQ) and azithromycin (AZM) polytherapy in a mock clinical trial. The MPS contained human heart muscle derived from patient-specific induced pluripotent stem cells. The effect of drug response was measured using outputs that correlate with clinical measurements such as QT interval (action potential duration) and drug-biomarker pairing. Chronic exposure to HCQ alone elicited early afterdepolarizations (EADs) and increased QT interval from day 6 onwards. AZM alone elicited an increase in QT interval from day 7 onwards and arrhythmias were observed at days 8 and 10. Monotherapy results closely mimicked clinical trial outcomes. Upon chronic exposure to HCQ and AZM polytherapy, we observed an increase in QT interval on days 4-8. Interestingly, a decrease in arrhythmias and instabilities was observed in polytherapy relative to monotherapy, in concordance with published clinical trials. Furthermore, biomarkers, most of them measurable in patients serum, were identified for negative effects of single drug or polytherapy on tissue contractile function, morphology, and antioxidant protection. The cardiac MPS can predict clinical arrhythmias associated with QT prolongation and rhythm instabilities. This high content system can help clinicians design their trials, rapidly project cardiac outcomes, and define new monitoring biomarkers to accelerate access of patients to safe COVID-19 therapeutics.

Strategies for infection control and prevalence of anti-SARS-CoV-2 IgG in 4,554 employees of a university hospital in Munich, Germany (preprint)

Background Hospital staff are at high risk of infection during the coronavirus disease (COVID-19) pandemic. We analysed the exposure characteristics, efficacy of protective measures, and transmission dynamics in this hospital-wide prospective seroprevalence study. Methods and Findings Overall, 4554 individuals were tested for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies using a chemiluminescent immunoassay. Individual risk factors, use of personal protective equipment (PPE), occupational exposure, previous SARS-CoV-2 infection, and symptoms were assessed using a questionnaire and correlated to anti-SARS-CoV-2 IgG antibody titres and PCR testing results. Odds ratios with corresponding exact 95% confidence intervals were used to evaluate associations between individual factors and seropositivity. Spatio-temporal trajectories of SARS-CoV-2-infected patients and staff mobility within the hospital were visualised to identify local hotspots of virus transmission. The overall seroprevalence of anti-SARS-CoV-2-IgG antibody was 2.4% [95% CI 1.9-2.9]. Patient-facing staff, including those working in COVID-19 areas, had a similar probability of being seropositive as non-patient-facing staff. Prior interaction with SARS-CoV-2-infected co-workers or private contacts and unprotected exposure to COVID-19 patients increased the probability of seropositivity. Loss of smell and taste had the highest positive predictive value for seropositivity. The rate of asymptomatic SARS-CoV-2 infections was 25.9%, and higher anti-SARS-CoV-2 IgG antibody titres were observed in symptomatic individuals. Spatio-temporal hotspots of SARS-CoV-2-positive staff and patients only showed partial overlap. Conclusions Patient-facing work in a healthcare facility during the SARS-CoV-2 pandemic may be safe if adequate PPE and hygiene measures are applied. The high numbers of asymptomatic SARS-CoV-2 infections that escaped detection by symptomatic testing underline the value of cross-sectional seroprevalence studies. Unprotected contact is a major risk factor for infection and argues for the rigorous implementation of hygiene measures.

Intensive care risk estimation in COVID-19 pneumonia based on clinical and imaging parameters: experiences from the Munich cohort (preprint)

Background: The rapidly evolving dynamics of coronavirus disease 2019 (COVID-19) and the steadily increasing infection numbers require diagnostic tools to identify patients at high risk for a severe disease course. Here we evaluate clinical and imaging parameters for estimating the need of intensive care unit (ICU) treatment. Methods: We collected clinical, laboratory and imaging data from 65 patients with confirmed COVID-19 infection based on PCR positivity. IL-6, CRP, leukocyte and lymphocyte counts were determined in blood samples. Two radiologists evaluated the severity of imaging findings in computed tomography (CT) images on a scale from 1 (no characteristic signs of COVID-19) to 5 (confluent ground glass opacities in over 50% of the lung parenchyma). The volume of affected lung was quantified using commercially available software. Machine learning modelling was performed to estimate the risk for intensive care unit treatment. Findings: Patients with a severe course of COVID-19 had significantly increased IL-6, CRP and leukocyte counts and significantly decreased lymphocyte counts. The radiological severity grading was significantly increased in ICU patients. Multivariate random forest modelling showed a mean +/- standard deviation sensitivity, specificity and accuracy of 0.72 +/- 0.1, 0.86 +/- 0.16 and 0.80 +/- 0.1 and a ROC-AUC of 0.79 +/- 0.1. The most important predictive parameters were affected lung volume, radiological severity score, CRP and IL-6. Summary and Conclusion: Estimation of need for intensive care treatment is possible based on the clinical and radiological parameters.

COVID-19 in people living with human immunodeficiency virus: A case series of 33 patients (preprint)

Data on people living with human immunodeficiency virus (PLWH) in the current SARS-CoV-2 pandemic is still scarce. This case series of 33 PLWH patients with COVID-19 reveals symptoms and outcome in this special population. Three out of 32 patients with documented outcome died (9%). However, 91% of the patients recovered and 76% have been classified as mild cases, indicating that there is no excess morbidity and mortality among PLWH with symptomatic COVID-19. All patients were on antiretroviral treatment, of them 22 on tenofovir-containing regimen, and 4 on the protease inhibitor darunavir.