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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-332881

ABSTRACT

Summary SARS-CoV-2-neutralizing antibodies play a critical role for protection and treatment of COVID-19. Viral antibody evasion therefore threatens essential prophylactic and therapeutic measures. The high number of mutations in the Omicron BA.1 sublineage results in markedly reduced neutralization susceptibility. Consistently, Omicron is associated with lower vaccine effectiveness and a high re-infection rate. Notably, newly emerging Omicron sublineages (BA.1.1, BA.2) have rapidly become dominant. Here, we determine polyclonal serum activity against BA.1, BA.1.1 and BA.2 in 50 convalescent or vaccinated individuals as well as delineate antibody sensitivities on a monoclonal level using 163 antibodies. Our study reveals a significant but comparable reduction of serum activity against Omicron sublineages which markedly increases after booster immunization. However, notable differences in sensitivity to individual antibodies demonstrate distinct escape patterns of BA.1 and BA.2 that also affect antibodies in clinical use. The results have strong implications for vaccination strategies and antibody use in prophylaxis and therapy.

2.
iScience ; 25(3): 103951, 2022 Mar 18.
Article in English | MEDLINE | ID: covidwho-1747872

ABSTRACT

Preexisting immunity against SARS-CoV-2 may have critical implications for our understanding of COVID-19 susceptibility and severity. The presence and clinical relevance of a preexisting B cell immunity remain to be fully elucidated. Here, we provide a detailed analysis of the B cell immunity to SARS-CoV-2 in unexposed individuals. To this end, we extensively investigated SARS-CoV-2 humoral immunity in 150 adults sampled pre-pandemically. Comprehensive screening of donor plasma and purified IgG samples for binding and neutralization in various functional assays revealed no substantial activity against SARS-CoV-2 but broad reactivity to endemic betacoronaviruses. Moreover, we analyzed antibody sequences of 8,174 putatively SARS-CoV-2-reactive B cells at a single cell level and generated and tested 158 monoclonal antibodies. None of these antibodies displayed relevant binding or neutralizing activity against SARS-CoV-2. Taken together, our results show no evidence of competent preexisting antibody and B cell immunity against SARS-CoV-2 in unexposed adults.

3.
J Infect Dis ; 2022 Feb 16.
Article in English | MEDLINE | ID: covidwho-1740903

ABSTRACT

The aim of this retrospective analysis was to provide information on how infections with RSV and SARS-CoV-2 differ in symptoms, clinical course, outcome and the utilization of hospital care. We investigated 748 PCR results from symptomatic children aged 0 - 4 years in Cologne, Germany. 169 patients were tested positive for RSV (22.6%) and 24 children for SARS-CoV-2 (3.2%). Symptomatic patients with RSV-infection were hospitalized significantly longer. RSV-positive patients needed O2-supplementation significantly more often as well as High Flow-therapy. With regard to care efforts, RSV-infected patients put higher pressure on the hospital and utilized more hospital resources.

4.
Emerg Infect Dis ; 28(5)2022 Mar 08.
Article in English | MEDLINE | ID: covidwho-1731731

ABSTRACT

To determine neutralizing activity against the severe acute respiratory syndrome coronavirus 2 ancestral strain and 4 variants of concern, we tested serum from 30 persons with breakthrough infection after 2-dose vaccination. Cross-variant neutralizing activity was comparable to that after 3-dose vaccination. Shorter intervals between vaccination and breakthrough infection correlated with lower neutralizing titers.

6.
Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology ; 2022.
Article in English | EuropePMC | ID: covidwho-1695511

ABSTRACT

Background Rapid antigen detection tests (RADT) are commonly used as SARS-CoV-2 diagnostic tests both by medical professionals and laypeople. However, the performance of RADT in vaccinated individuals has not been fully investigated. Objectives RT-qPCR and rapid antigen detection testing were performed to evaluate the performance of the Standard Q COVID-19 Ag Test in detecting SARS-CoV-2 breakthrough infections in vaccinated individuals. Study design Two swab specimens, one for RT-qPCR and one for RADT, were collected from vaccinated individuals in an outpatient clinic. For comparison of RADT performance in vaccinated and unvaccinated individuals, a dataset already published by this group was used as reference. Results A total of 696 samples were tested with both RT-qPCR and RADT that included 692 (99.4%) samples from vaccinated individuals. Of these, 76 (11.0%) samples were detected SARS-CoV-2 positive by RT-qPCR and 45 (6.5%) samples by the Standard Q COVID-19 Ag test. Stratified by Ct values, sensitivity of the RADT was 100.0%, 94.4% and 81.1% for Ct ≤ 20 (n=18), Ct ≤ 25 (n=36) and Ct ≤ 30 (n=53), respectively. Samples with Ct values ≥ 30 (n=23) were not detected. Overall RADT specificity was 99.7% and symptom status did not affect RADT performance. Notably, RADT detected 4 out of 4 samples of probable Omicron variant infection based on single nucleotide polymorphism analysis. Conclusion Our results show that RADT testing remains a valuable tool in detecting breakthrough infections with high viral RNA loads.

7.
J Clin Virol ; 148: 105119, 2022 03.
Article in English | MEDLINE | ID: covidwho-1693295

ABSTRACT

BACKGROUND: Rapid antigen detection tests (RADT) are commonly used as SARS-CoV-2 diagnostic tests both by medical professionals and laypeople. However, the performance of RADT in vaccinated individuals has not been fully investigated. OBJECTIVES: RT-qPCR and rapid antigen detection testing were performed to evaluate the performance of the Standard Q COVID-19 Ag Test in detecting SARS-CoV-2 breakthrough infections in vaccinated individuals. STUDY DESIGN: Two swab specimens, one for RT-qPCR and one for RADT, were collected from vaccinated individuals in an outpatient clinic. For comparison of RADT performance in vaccinated and unvaccinated individuals, a dataset already published by this group was used as reference. RESULTS: During the delta wave, a total of 696 samples were tested with both RT-qPCR and RADT that included 692 (99.4%) samples from vaccinated individuals. Of these, 76 (11.0%) samples were detected SARS-CoV-2 positive by RT-qPCR and 45 (6.5%) samples by the Standard Q COVID-19 Ag test. Stratified by Ct values, sensitivity of the RADT was 100.0%, 94.4% and 81.1% for Ct ≤ 20 (n=18), Ct ≤ 25 (n=36) and Ct ≤ 30 (n=53), respectively. Samples with Ct values ≥ 30 (n=23) were not detected. Overall RADT specificity was 99.7% and symptom status did not affect RADT performance. Notably, RADT detected 4 out of 4 samples of probable Omicron variant infection based on single nucleotide polymorphism analysis. CONCLUSION: Our results show that RADT testing remains a valuable tool in detecting breakthrough infections with high viral RNA loads.


Subject(s)
Antigens, Viral/analysis , COVID-19 Serological Testing/standards , COVID-19 , Vaccination , COVID-19/diagnosis , Humans , Reproducibility of Results , SARS-CoV-2 , Sensitivity and Specificity
8.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-322700

ABSTRACT

Innate immunity triggers responsible for viral control or hyperinflammation in COVID- 19 are largely unknown. Here we show that the SARS-CoV-2 spike protein primes inflammasome activation and interleukin 1-beta (IL-1β) secretion in macrophages derived from COVID-19 patients but not in macrophages from healthy SARS-CoV-2 naïve controls. Chemical NLRP3 inhibition blocks spike protein-induced IL-1β secretion ex vivo . These findings can accelerate research on COVID-19 vaccine design and drug treatment.

9.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327477

ABSTRACT

SARS-CoV-2 mRNA vaccination of healthy individuals is highly immunogenic and protective against severe COVID-19. However, there are limited data on how disease-modifying therapies (DMTs) alter SARS-CoV-2 mRNA vaccine immunogenicity in patients with autoimmune diseases. Here we investigated the induction and stability of vaccine-specific antibodies, B cells, and T cells in multiple sclerosis (MS) patients on different DMTs in a prospective cohort study up to 6 months after homologous prime-boost mRNA vaccination. We analysed 103 MS patients of which 86 received anti-CD20-based B cell depletion (aCD20-BCD), fingolimod, interferon-β, dimethyl fumarate, glatiramer acetate, teriflunomide or natalizumab, and compared them to 17 untreated MS patients. In contrast to all other DMTs and untreated patients, treatment with aCD20-BCD or fingolimod significantly reduced anti-S1 IgG, serum neutralizing activity, and RBD- and S2-specific B cells. MS patients receiving fingolimod additionally lacked S1- and S2-reactive CD4 + T cell responses. The duration of fingolimod treatment, rather than peripheral blood B and T cell counts prior to vaccination, determined whether patients successfully developed humoral immune responses. Fingolimod blocks the ability of immune cells to recirculate and migrate within secondary lymphoid organs demonstrating that functional immune responses require not only immune cells themselves but also access of these cells to the site of inoculation and their unimpeded movement. The absence of humoral and T cell responses in fingolimod-treated MS patients suggests that these patients are at risk for severe SARS-CoV-2 infections despite vaccination, which is highly relevant for clinical decision-making and adapted protective measures, particularly in light of additional recently approved S1P receptor antagonists for MS treatment.

10.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327432

ABSTRACT

Systematic SARS-CoV-2 testing is a valuable tool for infection control and surveillance 1 . However, broad application of high sensitive RT-qPCR testing in children is often hampered due to unpleasant sample collection, limited RT-qPCR capacities, and high costs 2–4 . Here, we developed a high-throughput approach (‘Lolli-Method’) for sensitive SARS-CoV-2 detection in children, combining non-invasive sample collection with an RT-qPCR-pool testing strategy. SARS-CoV-2 infections were diagnosed with sensitivities of 100% and 93.9% when viral loads were >10 6 copies/ml and >10 3 copies/ml in corresponding Naso-/Oropharyngeal-swabs, respectively. For effective application of the Lolli-Method in schools and daycare facilities, SIR-modeling indicated a preferred frequency of two tests per week. The developed test strategy was implemented in 3,700 schools and 698 daycare facilities in Germany, screening over 800,000 individuals twice per week. In a period of 3 months, 6,364 pool-RT-qPCRs tested positive (0.64%) ranging from 0.05% to 2.61% per week. Notably, infections correlated with local SARS-CoV-2 incidences as well as with a school social deprivation index. Moreover, in comparison with the alpha variant, statistical modeling revealed a 31% increase for multiple (≥2 children) infections per class following infections with the delta variant 5 . We conclude that the Lolli-Method is a powerful tool for SARS-CoV-2 surveillance and infection control in schools and daycare facilities.

11.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327374

ABSTRACT

Elderly individuals are at high risk for severe COVID-19. Due to modest vaccine responses compared to younger individuals and the time elapsed since prioritized vaccinations, the emerging immune-evasive Omicron variant of SARS-CoV-2 is a particular concern for the elderly. Here we longitudinally determined SARS-CoV-2-neutralizing serum activity against different variants in a cohort of 37 individuals with a median age of 82 years. Participants were followed for 10 months after an initial two-dose BNT162b2 vaccination and up to 4.5 months after a BNT162b2 booster. Detectable Omicron-neutralizing activity was nearly absent after two vaccinations but elicited in 89% of individuals by the booster immunization. Neutralizing titers against the Wu01, Delta, and Omicron variants showed similar post-boost declines and 81% of individuals maintained detectable activity against Omicron. Our study demonstrates the mRNA booster effectiveness in inducing anti-Omicron activity and provides critical information on vaccine response durability in the highly vulnerable elderly population.

13.
Nat Med ; 28(3): 477-480, 2022 03.
Article in English | MEDLINE | ID: covidwho-1632860

ABSTRACT

The Omicron variant of SARS-CoV-2 is causing a rapid increase in infections across the globe. This new variant of concern carries an unusually high number of mutations in key epitopes of neutralizing antibodies on the viral spike glycoprotein, suggesting potential immune evasion. Here we assessed serum neutralizing capacity in longitudinal cohorts of vaccinated and convalescent individuals, as well as monoclonal antibody activity against Omicron using pseudovirus neutralization assays. We report a near-complete lack of neutralizing activity against Omicron in polyclonal sera from individuals vaccinated with two doses of the BNT162b2 COVID-19 vaccine and from convalescent individuals, as well as resistance to different monoclonal antibodies in clinical use. However, mRNA booster immunizations in vaccinated and convalescent individuals resulted in a significant increase of serum neutralizing activity against Omicron. This study demonstrates that booster immunizations can critically improve the humoral immune response against the Omicron variant.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Immunization, Secondary , RNA, Messenger , SARS-CoV-2/genetics
14.
Cell Host Microbe ; 30(1): 69-82.e10, 2022 01 12.
Article in English | MEDLINE | ID: covidwho-1638702

ABSTRACT

A fraction of COVID-19 convalescent individuals mount a potent antibody response to SARS-CoV-2 with cross-reactivity to SARS-CoV-1. To uncover their humoral response in detail, we performed single B cell analysis from 10 SARS-CoV-2 elite neutralizers. We isolated and analyzed 126 monoclonal antibodies, many of which were sarbecovirus cross-reactive, with some displaying merbecovirus- and embecovirus-reactivity. Several isolated broadly neutralizing antibodies were effective against B.1.1.7, B.1.351, B.1.429, B.1.617, and B.1.617.2 variants and 19 prominent potential escape sites. Furthermore, assembly of 716,806 SARS-CoV-2 sequences predicted emerging escape variants, which were also effectively neutralized. One of these broadly neutralizing potent antibodies, R40-1G8, is a IGHV3-53 RBD-class-1 antibody. Remarkably, cryo-EM analysis revealed that R40-1G8 has a flexible binding mode, targeting both "up" and "down" conformations of the RBD. Given the threat of emerging SARS-CoV-2 variants, we demonstrate that elite neutralizers are a valuable source for isolating ultrapotent antibody candidates to prevent and treat SARS-CoV-2 infection.


Subject(s)
Antibodies, Viral/immunology , Broadly Neutralizing Antibodies/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Animals , Antibodies, Monoclonal/immunology , COVID-19/virology , Cells, Cultured , Chlorocebus aethiops , Cross Reactions/immunology , Female , HEK293 Cells , Humans , Male , Middle Aged , Neutralization Tests/methods , Spike Glycoprotein, Coronavirus/immunology , Vero Cells
15.
Front Immunol ; 12: 798276, 2021.
Article in English | MEDLINE | ID: covidwho-1606542

ABSTRACT

Effects of initiation of programmed-death-protein 1 (PD1) blockade during active SARS-CoV-2 infection on antiviral immunity, COVID-19 course, and underlying malignancy are unclear. We report on the management of a male in his early 40s presenting with highly symptomatic metastatic lung cancer and active COVID-19 pneumonia. After treatment initiation with pembrolizumab, carboplatin, and pemetrexed, the respiratory situation initially worsened and high-dose corticosteroids were initiated due to suspected pneumonitis. After improvement and SARS-CoV-2 clearance, anti-cancer treatment was resumed without pembrolizumab. Immunological analyses with comparison to otherwise healthy SARS-CoV-2-infected ambulatory patients revealed a strong humoral immune response with higher levels of SARS-CoV-2-reactive IgG and neutralizing serum activity. Additionally, sustained increase of Tfh as well as activated CD4+ and CD8+ T cells was observed. Sequential CT scans showed regression of tumor lesions and marked improvement of the pulmonary situation, with no signs of pneumonitis after pembrolizumab re-challenge as maintenance. At the latest follow-up, the patient is ambulatory and in ongoing partial remission on pembrolizumab. In conclusion, anti-PD1 initiation during active COVID-19 pneumonia was feasible and cellular and humoral immune responses to SARS-CoV-2 appeared enhanced in our hospitalized patient. However, distinguishing COVID-19-associated changes from anti-PD1-associated immune-related pneumonitis posed a considerable clinical, radiographic, and immunologic challenge.


Subject(s)
Adrenal Cortex Hormones/therapeutic use , COVID-19/drug therapy , Carcinoma, Non-Small-Cell Lung/drug therapy , Immune Checkpoint Inhibitors/therapeutic use , Lung Neoplasms/drug therapy , SARS-CoV-2/drug effects , Adult , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/virology , COVID-19/complications , COVID-19/immunology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Carcinoma, Non-Small-Cell Lung/complications , Carcinoma, Non-Small-Cell Lung/immunology , Humans , Immunity, Humoral/drug effects , Immunity, Humoral/immunology , Lung Neoplasms/complications , Lung Neoplasms/immunology , Male , Neoplasm Metastasis , Pneumonia/immunology , Pneumonia/prevention & control , Pneumonia/virology , SARS-CoV-2/immunology
17.
Lancet Respir Med ; 9(11): 1255-1265, 2021 11.
Article in English | MEDLINE | ID: covidwho-1594095

ABSTRACT

BACKGROUND: Heterologous vaccine regimens have been widely discussed as a way to mitigate intermittent supply shortages and to improve immunogenicity and safety of COVID-19 vaccines. We aimed to assess the reactogenicity and immunogenicity of heterologous immunisations with ChAdOx1 nCov-19 (AstraZeneca, Cambridge, UK) and BNT162b2 (Pfizer-BioNtech, Mainz, Germany) compared with homologous BNT162b2 and ChAdOx1 nCov-19 immunisation. METHODS: This is an interim analysis of a prospective observational cohort study enrolling health-care workers in Berlin (Germany) who received either homologous ChAdOx1 nCov-19 or heterologous ChAdOx1 nCov-19-BNT162b2 vaccination with a 10-12-week vaccine interval or homologous BNT162b2 vaccination with a 3-week vaccine interval. We assessed reactogenicity after the first and second vaccination by use of electronic questionnaires on days 1, 3, 5, and 7. Immunogenicity was measured by the presence of SARS-CoV-2-specific antibodies (full spike-IgG, S1-IgG, and RBD-IgG), by an RBD-ACE2 binding inhibition assay (surrogate SARS-CoV-2 virus neutralisation test), a pseudovirus neutralisation assay against two variants of concerns (alpha [B.1.1.7] and beta [B.1.351]), and anti-S1-IgG avidity. T-cell reactivity was measured by IFN-γ release assay. FINDINGS: Between Dec 27, 2020, and June 14, 2021, 380 participants were enrolled in the study, with 174 receiving homologous BNT162b2 vaccination, 38 receiving homologous ChAdOx1 nCov-19 vaccination, and 104 receiving ChAdOx1 nCov-19-BNT162b2 vaccination. Systemic symptoms were reported by 103 (65%, 95% CI 57·1-71·8) of 159 recipients of homologous BNT162b2, 14 (39%, 24·8-55·1) of 36 recipients of homologous ChAdOx1 nCov-19, and 51 (49%, 39·6-58·5) of 104 recipients of ChAdOx1 nCov-19-BNT162b2 after the booster immunisation. Median anti-RBD IgG levels 3 weeks after boost immunisation were 5·4 signal to cutoff ratio (S/co; IQR 4·8-5·9) in recipients of homologous BNT162b2, 4·9 S/co (4·3-5·6) in recipients of homologous ChAdOx1 nCov-19, and 5·6 S/co (5·1-6·1) in recipients of ChAdOx1 nCov-19- BNT162b2. Geometric mean of 50% inhibitory dose against alpha and beta variants were highest in recipients of ChAdOx1 nCov-19-BNT162b2 (956·6, 95% CI 835·6-1095, against alpha and 417·1, 349·3-498·2, against beta) compared with those in recipients of homologous ChAdOx1 nCov-19 (212·5, 131·2-344·4, against alpha and 48·5, 28·4-82·8, against beta; both p<0·0001) or homologous BNT162b2 (369·2, 310·7-438·6, against alpha and 72·4, 60·5-86·5, against beta; both p<0·0001). SARS-CoV-2 S1 T-cell reactivity 3 weeks after boost immunisation was highest in recipients of ChAdOx1 nCov-19-BNT162b2 (median IFN-γ concentration 4762 mIU/mL, IQR 2723-8403) compared with that in recipients of homologous ChAdOx1 nCov-19 (1061 mIU/mL, 599-2274, p<0·0001) and homologous BNT162b2 (2026 mIU/mL, 1459-4621, p=0·0008) vaccination. INTERPRETATION: The heterologous ChAdOx1 nCov-19-BNT162b2 immunisation with 10-12-week interval, recommended in Germany, is well tolerated and improves immunogenicity compared with homologous ChAdOx1 nCov-19 vaccination with 10-12-week interval and BNT162b2 vaccination with 3-week interval. Heterologous prime-boost immunisation strategies for COVID-19 might be generally applicable. FUNDING: Forschungsnetzwerk der Universitätsmedizin zu COVID-19, the German Ministry of Education and Research, Zalando SE.


Subject(s)
/immunology , COVID-19 , Immunogenicity, Vaccine , Antibodies, Viral/blood , COVID-19/prevention & control , Germany , Health Personnel , Humans , Immunoglobulin G/blood , Neutralization Tests , Prospective Studies , SARS-CoV-2 , Vaccination
18.
Microorganisms ; 10(1)2021 Dec 21.
Article in English | MEDLINE | ID: covidwho-1580569

ABSTRACT

Dialysis patients and kidney transplant (KTX) recipients suffer from an impaired immune system and show a decreased response to the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) vaccination. We performed a retrospective analysis of 1505 serological SARS-CoV-2 measurements obtained from 887 dialysis patients and 86 KTX recipients. The results were separated by patient subgroups (dialysis/KTX) as well as SARS-CoV-2 status. The latter criterion included SARS-CoV-2-naïve patients with or without COVID-19 vaccination and convalescent patients receiving a booster shot. Serologies of 27 vaccinated healthy individuals served as the reference group. Vaccine-induced cellular immune response was quantified by an interferon-γ release assay in 32 KTX recipients. We determined seroconversion rates of 92.6%, 93.4%, and 71.4% in dialysis patients vaccinated with either BNT162b2, mRNA-1273, or AZD1222, respectively. Vaccination-induced anti-SARS-CoV-2 antibody titers were lower in dialysis patients compared to healthy individuals, and vaccination with mRNA-1273 induced higher titers than BNT162b2. The initial seroconversion rate was 39.5% in KTX recipients vaccinated with BNT162b2. A linear regression model identified medication with mycophenolate-mofetil/mycophenolic acid as an independent risk factor for missing seroconversion. Within a cohort of 32 KTX recipients, cellular and humoral immune reactivity to SARS-CoV-2 was detectable in three patients only. Conclusively, vaccine-induced seroconversion rates were similar in dialysis patients compared to healthy individuals but were strongly impaired in KTX recipients. Anti-SARS-CoV-2 IgG titers elicited by double active immunization were significantly lower in both cohorts compared to healthy individuals, and immune responses to vaccination vanished quickly.

19.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296695

ABSTRACT

The Omicron variant of SARS-CoV-2 is causing a rapid increase in infections in various countries. This new variant of concern carries an unusually high number of mutations in key epitopes of neutralizing antibodies on the spike glycoprotein, suggesting potential immune evasion. Here we assessed serum neutralizing capacity in longitudinal cohorts of vaccinated and convalescent individuals, as well as monoclonal antibody activity against Omicron using pseudovirus neutralization assays. We report a near-complete lack of neutralizing activity against Omicron in polyclonal sera after two doses of the BNT162b2 vaccine, in convalescent individuals, as well as resistance to different monoclonal antibodies in clinical use. However, mRNA booster immunizations in vaccinated and convalescent individuals resulted in a significant increase of serum neutralizing activity against Omicron. Our study demonstrates that booster immunizations will be critical to substantially improve the humoral immune response against the Omicron variant.

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