Anti-SARS-CoV-2 antibody containing plasma improves outcome in patients with hematologic or solid cancer and severe COVID-19 via increased neutralizing antibody activity. A randomized clinical trial (preprint)

Cancer patients are at high risk of severe COVID-19 with high morbidity and mortality. Further, impaired humoral response renders SARS-CoV-2 vaccines less effective and treatment options are scarce. Randomized trials using convalescent plasma are missing for high-risk patients. Here, we performed a multicenter trial (https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-001632-10/DE) in hospitalized patients with severe COVID-19 within four risk groups (1, cancer; 2, immunosuppression; 3, lab-based risk factors; 4, advanced age) randomized to standard of care (CONTROL) or standard of care plus convalescent/vaccinated anti-SARS-CoV-2 plasma (PLASMA). For the four groups combined, PLASMA did not improve clinically compared to CONTROL (HR 1.29; p=0.205). However, cancer patients experienced shortened median time to improvement (HR 2.50, p=0.003) and superior survival in PLASMA vs. CONTROL (HR 0.28; p=0.042). Neutralizing antibody activity increased in PLASMA but not in CONTROL cancer patients (p=0.001). Taken together, convalescent/vaccinated plasma may improve COVID-19 outcome in cancer patients unable to intrinsically generate an adequate immune response.

Three separate spike antigen exposures by COVID-19 vaccination or SARS-CoV-2 infection elicit strong humoral immune responses in healthcare workers (preprint)

As part of our ongoing prospective seroprevalence study, we assessed the SARS-CoV-2 infection and COVID-19 vaccination-induced immunity of 697 hospital workers at the University Medical Center Hamburg-Eppendorf between January 17 and 31, 2022. The overall prevalence of anti-NC-SARS-CoV-2 antibodies indicating prior infection was 9.8% (n=68) and thus lower than the seroprevalence in the general population in Hamburg. At the current study visit, 99.3% (n=692) had received at least one vaccine dose and 93.1% (n=649) had received at least three vaccine doses. All vaccinated individuals had detectable anti-S1-RBD-SARS-CoV-2 antibodies (median AU/ml [IQR]: 13.891 [8.505 to 23.543]), indicating strong protection against severe COVID-19. In addition, we show that individuals who received three COVID-19 vaccine doses (median AU/ml [IQR]: 13.856 [8.635 to 22.705]), and those who resolved a prior SARS-CoV-2 infection and received two COVID-19 vaccine doses (median AU/ml [IQR] 13.409 [6.934 to 25.000]) exhibited the strongest humoral immune responses. The low prevalence of anti-NC-SARS-CoV-2 antibodies indicates persistent effectiveness of established infection control interventions in preventing nosocomial SARS-CoV-2 transmission with the delta and omicron viral variants as predominant strains. Our study further indicates that three exposures to the viral spike protein by either SARS-CoV-2 infection or COVID-19 vaccination are necessary to elicit particularly strong humoral immune responses, which supports current vaccination recommendations.

Low SARS-CoV-2 infection rate and high vaccine-induced immunity among German healthcare workers at the end of the third wave of the COVID-19 pandemic (preprint)

In this longitudinal cohort study, we assessed the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) seroconversion rates and analyzed the coronavirus disease 2019 (COVID-19) vaccine-induced immunity of 872 hospital workers at the University Medical Center Hamburg-Eppendorf between May 11 and May 31, 2021. The overall seroprevalence of anti-NC-SARS-CoV-2 antibodies was 4.7% (n=41), indicating low SARS-CoV-2 infection rates and persistent effectiveness of hospital-wide infection control interventions during the second and third wave of the pandemic. In total, 92.7% (n=808) out of the entire study cohort, 98.2% (n=325) of those who had been vaccinated once and all 393 individuals who had been vaccinated twice had detectable anti-S1-RBD-SARS-CoV-2 antibody titers and no significant differences in vaccine-induced immune response were detected between male and female individuals and between different age groups. Vaccinated study participants with detectable anti-NC-SARS-CoV-2 antibody titers (n=30) developed generally higher anti-S1-RBD-SARS-CoV-2 antibody titers compared to anti-NC-SARS-CoV-2 negative individuals (n=694) (median titer: 7812 vs. 345 BAU/ml, p<0.0001). Furthermore, study participants who received heterologous vaccination with AZD1222 followed by an mRNA vaccine showed markedly higher anti-S1-RBD-SARS-CoV-2 antibody titers than individuals who received two doses of an mRNA vaccine or two doses of AZD1222 (median titer: AZD1222 / AZD1222: 1069 BAU/ml, mRNA / mRNA: 1388 BAU/ml, AZD1222/mRNA: 9450 BAU/ml; p<0.0001). Our results demonstrate that infection control interventions were generally effective in preventing nosocomial transmission of SARS-CoV-2 and that COVID-19 vaccines can elicit strong humoral responses in the majority of a real-world cohort of hospital workers.

Validation of a prospective urinalysis-based prediction model for ICU-resources and outcome of Covid-19 disease: A multicenter cohort study (preprint)

Purpose: Identifying preventive strategies in Covid-19 patients helps to improve ICU-resource-allocation and reduce mortality. We recently demonstrated in a post-mortem cohort that SARS-CoV-2 renal tropism was associated with kidney injury, disease severity and mortality. We also proposed an algorithm to predict the need for ICU-resources and the risk of adverse outcomes in Covid-19 patients harnessing urinalysis and protein/coagulation parameters on admission for signs of kidney injury. Here, we aimed to validate this hypothesis in a multicenter cohort. Methods: Patients hospitalized for Covid-19 at four tertiary centers were screened for an available urinalysis, serum albumin (SA) and antithrombin-III activity (AT-III) obtained prospectively within 48h upon admission. The respective presumed risk for an unfavorable course was categorized as “low”, “intermediate” or “high”, depending on a normal urinalysis, an abnormal urinalysis with SA ≥2 g/dl and AT-III ≥70%, or an abnormal urinalysis with at least one SA or AT-III abnormality. Time to ICU or death within ten days served as primary, in-hospital mortality and required organ support served as secondary endpoints.Results: Among a total of N=223 screened patients, N=145 were eligible for enrollment, falling into the low (N=43), intermediate (N=84), and high risk (N=18) categories. The risk for ICU transfer or death was 100% in the high risk group and significantly elevated in the composite of high and intermediate risk as compared to the low risk group (63.7% vs. 27.9%; HR 2.6; 95%-CI 1.4 to 4.9; P=0.0020). Having an abnormal urinalysis was associated with mortality, need for mechanical ventilation, extra-corporeal membrane oxygenation (ECMO) or renal replacement therapy (RRT). Conclusion: Our data confirm that Covid-19-associated urine abnormalities on admission predict disease aggravation and need for ICU. By engaging a simple urine dipstick on hospital admission our algorithm allows for early preventive measures and appropriate patient stratification. (ClinicalTrials.gov number NCT04347824)

High effectiveness of multimodal infection control interventions in preventing SARS-CoV-2 infections in healthcare professionals: a prospective longitudinal seroconversion study (preprint)

Objective: To assess the effectiveness of multimodal infection control interventions in the prevention of SARS-CoV-2 infections in healthcare professionals. Design: Sequential follow-up study. Setting: Largest tertiary care centre in northern Germany. Participants: 1253 employees of the University Medical Center Hamburg-Eppendorf were sequentially assessed for the presence of SARS-CoV-2 IgG antibodies at the beginning of the covid-19 epidemic (20 March - 9 April), one month (20 April - 8 May), and another two months later (22 June - 24 July). Of those, 1026 were healthcare workers (HCWs) of whom 292 were directly involved in the care of covid-19 patients. During the study period, infection control interventions were deployed, those included i) strict barrier nursing of all known covid-19 patients including FFP2 (N95) masks, goggles, gloves, hoods and protective gowns, ii) visitor restrictions with access control at all hospital entries, iii) mandatory wearing of disposable face masks in all clinical settings, and iv) universal RT-PCR admission screening of patients. Main Outcome Measures: SARS-CoV-2 IgG seroconversion rate. Results: At the initial screening, ten participants displayed significant IgG antibody ratios. Another ten individuals showed seroconversion at the second time point one month later, only two further participants seroconverted during the subsequent two months. The overall SARS-CoV-2 seroprevalence in the study cohort at the last follow-up was 1.8%, the seroconversion rate dropped from 0.81% to 0.08% per month despite a longer observation period. Amongst HCWs seropositivity was increased in those directly involved in the care of patients with SARS-CoV-2 infections (3.8%, n=11) compared to other HCWs (1.4%, n=10, P=0.025). However, after the adoption of all multimodal infection control interventions seroconversions were observed in only two more HCWs, neither of whom were involved in inpatient care. Conclusion: Multimodal infection control and prevention interventions are highly effective in mitigating SARS-CoV-2 infections of healthcare professionals.

Distinct early IgA profile may determine severity of COVID-19 symptoms: an immunological case series (preprint)

SARS-CoV-2 is the causative agent of COVID-19 and is a severe threat to global health. Patients infected with SARS-CoV-2 show a wide range of symptoms and disease severity, while limited data is available on its immunogenicity. Here, the kinetics of the development of SARS-CoV-2-specific antibody responses in relation to clinical features and dynamics of specific B-cell populations are reported. Immunophenotyping of B cells was performed by flow cytometry with longitudinally collected PBMCs. In parallel, serum samples were analyzed for the presence of SARS-CoV-2-specific IgA, IgG, and IgM antibodies using whole proteome peptide microarrays. Soon after disease onset in a mild case, we observed an increased frequency of plasmablasts concomitantly with a strong SARS-CoV-2-specific IgA response. In contrast, a case with more severe progression showed a delayed, but eventually very strong and broad SARS-CoV-2-specific IgA response. This case study shows that determining SARS-CoV-2-specific antibody epitopes can be valuable to monitor the specificity and magnitude of the early B-cell response, which could guide the development of vaccine candidates. Follow-up studies are required to evaluate whether the kinetics and strength of the SARS-CoV-2-specific IgA response could be potential prognostic markers of viral control.