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1.
Nat Commun ; 13(1): 128, 2022 01 10.
Article in English | MEDLINE | ID: covidwho-1616978

ABSTRACT

The quality and persistence of children's humoral immune response following SARS-CoV-2 infection remains largely unknown but will be crucial to guide pediatric SARS-CoV-2 vaccination programs. Here, we examine 548 children and 717 adults within 328 households with at least one member with a previous laboratory-confirmed SARS-CoV-2 infection. We assess serological response at 3-4 months and 11-12 months after infection using a bead-based multiplex immunoassay for 23 human coronavirus antigens including SARS-CoV-2 and its Variants of Concern (VOC) and endemic human coronaviruses (HCoVs), and additionally by three commercial SARS-CoV-2 antibody assays. Neutralization against wild type SARS-CoV-2 and the Delta VOC are analysed in a pseudotyped virus assay. Children, compared to adults, are five times more likely to be asymptomatic, and have higher specific antibody levels which persist longer (96.2% versus 82.9% still seropositive 11-12 months post infection). Of note, symptomatic and asymptomatic infections induce similar humoral responses in all age groups. SARS-CoV-2 infection occurs independent of HCoV serostatus. Neutralization responses of children and adults are similar, although neutralization is reduced for both against the Delta VOC. Overall, the long-term humoral immune response to SARS-CoV-2 infection in children is of longer duration than in adults even after asymptomatic infection.

2.
Cell Rep ; 37(13): 110169, 2021 12 28.
Article in English | MEDLINE | ID: covidwho-1616407

ABSTRACT

The importance of pre-existing immune responses to seasonal endemic coronaviruses (HCoVs) for the susceptibility to SARS-CoV-2 infection and the course of COVID-19 is the subject of an ongoing scientific debate. Recent studies postulate that immune responses to previous HCoV infections can either have a slightly protective or no effect on SARS-CoV-2 pathogenesis and, consequently, be neglected for COVID-19 risk stratification. Challenging this notion, we provide evidence that pre-existing, anti-nucleocapsid antibodies against endemic α-coronaviruses and S2 domain-specific anti-spike antibodies against ß-coronavirus HCoV-OC43 are elevated in patients with COVID-19 compared to pre-pandemic donors. This finding is particularly pronounced in males and in critically ill patients. Longitudinal evaluation reveals that antibody cross-reactivity or polyclonal stimulation by SARS-CoV-2 infection are unlikely to be confounders. Thus, specific pre-existing immunity to seasonal coronaviruses may increase susceptibility to SARS-CoV-2 and predispose individuals to an adverse COVID-19 outcome, guiding risk management and supporting the development of universal coronavirus vaccines.


Subject(s)
COVID-19/immunology , Coronavirus/immunology , SARS-CoV-2/immunology , Adult , Antibodies/immunology , Antibodies, Viral/immunology , COVID-19/etiology , Coronavirus Infections/immunology , Coronavirus OC43, Human/immunology , Coronavirus OC43, Human/pathogenicity , Cross Reactions/immunology , Female , Germany , Humans , Immunity, Humoral/immunology , Immunoglobulin G/immunology , Longitudinal Studies , Male , Middle Aged , Pandemics , SARS-CoV-2/pathogenicity , Seasons , Severity of Illness Index , Spike Glycoprotein, Coronavirus/immunology
3.
EMBO Rep ; : e53865, 2021 Dec 20.
Article in English | MEDLINE | ID: covidwho-1579708

ABSTRACT

The ongoing COVID-19 pandemic and the emergence of new SARS-CoV-2 variants of concern (VOCs) requires continued development of effective therapeutics. Recently, we identified high-affinity neutralizing nanobodies (Nbs) specific for the receptor-binding domain (RBD) of SARS-CoV-2. Taking advantage of detailed epitope mapping, we generate two biparatopic Nbs (bipNbs) targeting a conserved epitope outside and two different epitopes inside the RBD:ACE2 interface. Both bipNbs bind all currently circulating VOCs with high affinities and are capable to neutralize cellular infection with VOC B.1.351 (Beta) and B.1.617.2 (Delta) in vitro. To assess if the bipNbs NM1267 and NM1268 confer protection against SARS-CoV-2 infection in vivo, human ACE2 transgenic mice are treated intranasally before infection with a lethal dose of SARS-CoV-2 B.1, B.1.351 (Beta) or B.1.617.2 (Delta). Nb-treated mice show significantly reduced disease progression and increased survival rates. Histopathological analyses further reveal a drastically reduced viral load and inflammatory response in lungs. These data suggest that both bipNbs are broadly active against a variety of emerging SARS-CoV-2 VOCs and represent easily applicable drug candidates.

4.
Cell reports ; 2021.
Article in English | EuropePMC | ID: covidwho-1565013

ABSTRACT

Wratil et al. find specific antibody responses against seasonal human coronaviruses, which cause the common cold, to be elevated in patients with COVID-19 compared to pre-pandemic blood donors. This specific immunity is likely pre-existing in patients and increases their susceptibility to SARS-CoV-2 and severity of COVID-19.

5.
Preprint in English | EuropePMC | ID: ppcovidwho-294629

ABSTRACT

Background: While SARS-CoV-2 vaccinations were successful in decreasing COVID-19 caseloads, recent increases in SARS-CoV-2 infections have led to questions about duration and quality of the subsequent immune response. While numerous studies have been published on immune responses triggered by vaccination, these often focused on the initial peak response generated in specific population subgroups (e.g. healthcare workers or immunocompromised individuals) and have often only examined the effects of one or two different immunisation schemes. Methods and Findings We analysed serum samples from participants of a large German seroprevalence study (MuSPAD) who had received all available vaccines and dose schedules (mRNA-1273, BNT162b2, AZD1222, Ad26.CoV2S.2 or a combination of AZD1222 plus either mRNA-1273 or BNT162b2). Antibody titers against various SARS-CoV-2 antigens and ACE2 binding inhibition against SARS-CoV-2 wild-type and the Alpha, Beta, Gamma and Delta variants of concern were analysed using a previously published multiplex immunoassay MULTICOV-AB and an ACE2-RBD competition assay. Among the different vaccines and their dosing regimens, homologous mRNA-based or heterologous prime-boost vaccination produced significantly higher antibody responses than vector-based homologous vaccination. Ad26.CoV2S.2 performance was significantly reduced, even compared to AZD1222, with 91.67% of samples being considered non-responsive forACE2 binding inhibition. mRNA-based vaccination induced a higher ratio of RBD- and S1-targeting antibodies than vector-based vaccination, which resulted in an increased proportion of S2-targeting antibodies. Previously infected individuals had a robust immune response once vaccinated, regardless of which vaccine they received. When examining antibody kinetics post-vaccination after homologous immunisation regimens, both titers and ACE2 binding inhibition peaked approximately 28 days post-vaccination and then decreased as time increased. Conclusions As one of the first and largest population-based studies to examine vaccine responses for all currently available immunisation schemes in Germany, we found that homologous mRNA or heterologous vaccination elicited the highest immune responses. The high percentage of non-responders for Ad26.CoV2.S requires further investigation and suggests that a booster dose with an mRNA-based vaccine may be necessary. The high responses seen in recovered and vaccinated individuals could aid future dose allocation, should shortages arise for certain manufacturers. Given the role of RBD- and S1-specific antibodies in neutralising SARS-CoV-2, their relative over-representation after mRNA vaccination may explain why mRNA vaccines have an increased efficacy compared to vector-based formulations. Further investigation on these differences will be of particular interest for vaccine development and efficacy, especially for the next-generation of vector-based vaccines.

6.
Preprint in English | EuropePMC | ID: ppcovidwho-293501

ABSTRACT

Background: While SARS-CoV-2 vaccinations were successful in decreasing COVID-19 caseloads, recent increases in SARS-CoV-2 infections have led to questions about duration and quality of the subsequent immune response. While numerous studies have been published on immune responses triggered by vaccination, these often focused on the initial peak response generated in specific population subgroups (e.g. healthcare workers or immunocompromised individuals) and have often only examined the effects of one or two different immunisation schemes. Methods and Findings We analysed serum samples from participants of a large German seroprevalence study (MuSPAD) who had received all available vaccines and dose schedules (mRNA-1273, BNT162b2, AZD1222, Ad26.CoV2S.2 or a combination of AZD1222 plus either mRNA-1273 or BNT162b2). Antibody titers against various SARS-CoV-2 antigens and ACE2 binding inhibition against SARS-CoV-2 wild-type and the Alpha, Beta, Gamma and Delta variants of concern were analysed using a previously published multiplex immunoassay MULTICOV-AB and an ACE2-RBD competition assay. Among the different vaccines and their dosing regimens, homologous mRNA-based or heterologous prime-boost vaccination produced significantly higher antibody responses than vector-based homologous vaccination. Ad26.CoV2S.2 performance was significantly reduced, even compared to AZD1222, with 91.67% of samples being considered non-responsive forACE2 binding inhibition. mRNA-based vaccination induced a higher ratio of RBD- and S1-targeting antibodies than vector-based vaccination, which resulted in an increased proportion of S2-targeting antibodies. Previously infected individuals had a robust immune response once vaccinated, regardless of which vaccine they received. When examining antibody kinetics post-vaccination after homologous immunisation regimens, both titers and ACE2 binding inhibition peaked approximately 28 days post-vaccination and then decreased as time increased. Conclusions As one of the first and largest population-based studies to examine vaccine responses for all currently available immunisation schemes in Germany, we found that homologous mRNA or heterologous vaccination elicited the highest immune responses. The high percentage of non-responders for Ad26.CoV2.S requires further investigation and suggests that a booster dose with an mRNA-based vaccine may be necessary. The high responses seen in recovered and vaccinated individuals could aid future dose allocation, should shortages arise for certain manufacturers. Given the role of RBD- and S1-specific antibodies in neutralising SARS-CoV-2, their relative over-representation after mRNA vaccination may explain why mRNA vaccines have an increased efficacy compared to vector-based formulations. Further investigation on these differences will be of particular interest for vaccine development and efficacy, especially for the next-generation of vector-based vaccines.

7.
EBioMedicine ; 70: 103524, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1356202

ABSTRACT

BACKGROUND: Patients with chronic renal insufficiency on maintenance haemodialysis face an increased risk of COVID-19 induced mortality and impaired vaccine responses. To date, only a few studies have addressed SARS-CoV-2 vaccine elicited immunity in this immunocompromised population. METHODS: We assessed immunogenicity of the mRNA vaccine BNT162b2 in at-risk dialysis patients and characterised systemic cellular and humoral immune responses in serum and saliva using interferon γ release assay and multiplex-based cytokine and immunoglobulin measurements. We further compared binding capacity and neutralization efficacy of vaccination-induced immunoglobulins against emerging SARS-CoV-2 variants Alpha, Beta, Epsilon and Cluster 5 by ACE2-RBD competition assay. FINDINGS: Patients on maintenance haemodialysis exhibit detectable but variable cellular and humoral immune responses against SARS-CoV-2 and variants of concern after a two-dose regimen of BNT162b2. Although vaccination-induced immunoglobulins were detectable in saliva and plasma, both anti-SARS-CoV-2 IgG and neutralization efficacy was reduced compared to a vaccinated non-dialysed control population. Similarly, T-cell mediated interferon γ release after stimulation with SARS-CoV-2 spike peptides was significantly diminished. INTERPRETATION: Quantifiable humoral and cellular immune responses after BNT162b2 vaccination in individuals on maintenance haemodialysis are encouraging, but urge for longitudinal follow-up to assess longevity of immunity. Diminished virus neutralization and interferon γ responses in the face of emerging variants of concern may favour this at-risk population for re-vaccination using modified vaccines at the earliest opportunity. FUNDING: Initiative and Networking Fund of the Helmholtz Association of German Research Centres, EU Horizon 2020 research and innovation program, State Ministry of Baden-Württemberg for Economic Affairs, Labour and Tourism.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Immunogenicity, Vaccine/immunology , SARS-CoV-2/immunology , Vaccines, Synthetic/immunology , Aged , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Female , Humans , Immunoglobulin G/immunology , Male , Middle Aged , Renal Dialysis/methods , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes/immunology , Vaccination/methods
8.
Nat Commun ; 12(1): 3109, 2021 05 25.
Article in English | MEDLINE | ID: covidwho-1243298

ABSTRACT

SARS-CoV-2 is evolving with mutations in the receptor binding domain (RBD) being of particular concern. It is important to know how much cross-protection is offered between strains following vaccination or infection. Here, we obtain serum and saliva samples from groups of vaccinated (Pfizer BNT-162b2), infected and uninfected individuals and characterize the antibody response to RBD mutant strains. Vaccinated individuals have a robust humoral response after the second dose and have high IgG antibody titers in the saliva. Antibody responses however show considerable differences in binding to RBD mutants of emerging variants of concern and substantial reduction in RBD binding and neutralization is observed against a patient-isolated South African variant. Taken together our data reinforce the importance of the second dose of Pfizer BNT-162b2 to acquire high levels of neutralizing antibodies and high antibody titers in saliva suggest that vaccinated individuals may have reduced transmission potential. Substantially reduced neutralization for the South African variant further highlights the importance of surveillance strategies to detect new variants and targeting these in future vaccines.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination , Adult , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antibody Formation , COVID-19/blood , Female , Gene Expression , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Male , Middle Aged , Mutation , Neutralization Tests , Protein Binding , Protein Domains/genetics , Receptors, Coronavirus/metabolism , Recombinant Proteins , SARS-CoV-2/genetics , Saliva/immunology , Saliva/virology
9.
EMBO Rep ; 22(5): e52325, 2021 05 05.
Article in English | MEDLINE | ID: covidwho-1204402

ABSTRACT

In light of the COVID-19 pandemic, there is an ongoing need for diagnostic tools to monitor the immune status of large patient cohorts and the effectiveness of vaccination campaigns. Here, we present 11 unique nanobodies (Nbs) specific for the SARS-CoV-2 spike receptor-binding domain (RBD), of which 8 Nbs potently inhibit the interaction of RBD with angiotensin-converting enzyme 2 (ACE2) as the major viral docking site. Following detailed epitope mapping and structural analysis, we select two inhibitory Nbs, one of which binds an epitope inside and one of which binds an epitope outside the RBD:ACE2 interface. Based on these, we generate a biparatopic nanobody (bipNb) with viral neutralization efficacy in the picomolar range. Using bipNb as a surrogate, we establish a competitive multiplex binding assay ("NeutrobodyPlex") for detailed analysis of the presence and performance of neutralizing RBD-binding antibodies in serum of convalescent or vaccinated patients. We demonstrate that NeutrobodyPlex enables high-throughput screening and detailed analysis of neutralizing immune responses in infected or vaccinated individuals, to monitor immune status or to guide vaccine design.


Subject(s)
COVID-19 , Single-Domain Antibodies , Antibodies, Viral/metabolism , Humans , Immunity , Pandemics , Protein Binding , SARS-CoV-2 , Single-Domain Antibodies/metabolism , Spike Glycoprotein, Coronavirus/metabolism
10.
ACS Infect Dis ; 7(6): 1596-1606, 2021 06 11.
Article in English | MEDLINE | ID: covidwho-1135641

ABSTRACT

The presence of antibodies against endemic coronaviruses has been linked to disease severity after SARS-CoV-2 infection. Assays capable of concomitantly detecting antibodies against endemic coronaviridae such as OC43, 229E, NL63, and SARS-CoV-2 may help to elucidate this question. We developed a serum screening platform using a bead-based Western blot system called DigiWest, capable of running hundreds of assays using microgram amounts of protein prepared directly from different viruses. Characterization of the immunoassay for detection of SARS-CoV-2 specific antibodies revealed a sensitivity of 90.3% and a diagnostic specificity of 98.1%. Concordance analysis with the SARS-CoV-2 immunoassays available by Roche, Siemens, and Euroimmun indicates comparable assay performances (Cohen's κ ranging from 0.8874 to 0.9508). Analogous assays for OC43, 229E, and NL63 were established and combined into one multiplex with the SARS-CoV-2 assay. Seroreactivity for different coronaviruses was detected with high incidence, and the multiplex assay was adapted for serum screening.


Subject(s)
COVID-19 , Coronaviridae , COVID-19 Testing , Humans , Plant Extracts , SARS-CoV-2
11.
Nat Commun ; 12(1): 1152, 2021 02 19.
Article in English | MEDLINE | ID: covidwho-1091492

ABSTRACT

The humoral immune response to SARS-CoV-2 is a benchmark for immunity and detailed analysis is required to understand the manifestation and progression of COVID-19, monitor seroconversion within the general population, and support vaccine development. The majority of currently available commercial serological assays only quantify the SARS-CoV-2 antibody response against individual antigens, limiting our understanding of the immune response. To overcome this, we have developed a multiplex immunoassay (MultiCoV-Ab) including spike and nucleocapsid proteins of SARS-CoV-2 and the endemic human coronaviruses. Compared to three broadly used commercial in vitro diagnostic tests, our MultiCoV-Ab achieves a higher sensitivity and specificity when analyzing a well-characterized sample set of SARS-CoV-2 infected and uninfected individuals. We find a high response against endemic coronaviruses in our sample set, but no consistent cross-reactive IgG response patterns against SARS-CoV-2. Here we show a robust, high-content-enabled, antigen-saving multiplex assay suited to both monitoring vaccination studies and facilitating epidemiologic screenings for humoral immunity towards pandemic and endemic coronaviruses.


Subject(s)
Antibodies, Viral/immunology , COVID-19 Serological Testing/methods , COVID-19/immunology , Cross Reactions , Immunity, Humoral , COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/immunology , Humans , Immunoassay , Immunoglobulin G/immunology , Phosphoproteins/immunology , SARS-CoV-2/immunology , Sensitivity and Specificity , Spike Glycoprotein, Coronavirus/immunology
12.
Nat Immunol ; 22(1): 74-85, 2021 01.
Article in English | MEDLINE | ID: covidwho-1065902

ABSTRACT

T cell immunity is central for the control of viral infections. To characterize T cell immunity, but also for the development of vaccines, identification of exact viral T cell epitopes is fundamental. Here we identify and characterize multiple dominant and subdominant SARS-CoV-2 HLA class I and HLA-DR peptides as potential T cell epitopes in COVID-19 convalescent and unexposed individuals. SARS-CoV-2-specific peptides enabled detection of post-infectious T cell immunity, even in seronegative convalescent individuals. Cross-reactive SARS-CoV-2 peptides revealed pre-existing T cell responses in 81% of unexposed individuals and validated similarity with common cold coronaviruses, providing a functional basis for heterologous immunity in SARS-CoV-2 infection. Diversity of SARS-CoV-2 T cell responses was associated with mild symptoms of COVID-19, providing evidence that immunity requires recognition of multiple epitopes. Together, the proposed SARS-CoV-2 T cell epitopes enable identification of heterologous and post-infectious T cell immunity and facilitate development of diagnostic, preventive and therapeutic measures for COVID-19.


Subject(s)
COVID-19/immunology , Epitopes, T-Lymphocyte/immunology , Peptides/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Viral Vaccines/immunology , COVID-19/prevention & control , COVID-19/virology , Cross Reactions/immunology , HLA-DR Antigens/immunology , HLA-DR Antigens/metabolism , Histocompatibility Antigens Class I/immunology , Histocompatibility Antigens Class I/metabolism , Humans , Immunologic Memory/immunology , SARS-CoV-2/physiology , T-Lymphocytes/metabolism , Viral Vaccines/administration & dosage
13.
ACS Sens ; 6(3): 703-708, 2021 03 26.
Article in English | MEDLINE | ID: covidwho-1047926

ABSTRACT

Immunological methods to detect SARS-CoV-2 seroconversion in humans are important to track COVID-19 cases and the humoral response to SARS-CoV-2 infections and immunization to future vaccines. The aim of this work was to develop a simple chromogenic magnetic bead-based immunoassay which allows rapid, inexpensive, and quantitative detection of human antibodies against SARS-CoV-2 in serum, plasma, or blood. Recombinant 6xHis-tagged SARS-CoV-2 Nucleocapsid protein was mobilized on the surface of Ni2+ magnetic beads and challenged with serum or blood samples obtained from controls or COVID-19 cases. The beads were washed, incubated with anti-human IgG-HPR conjugate, and immersed into a solution containing a chromogenic HPR substrate. Bead transfer and homogenization between solutions was aided by a simple low-cost device. The method was validated by two independent laboratories, and the performance to detect SARS-CoV-2 seroconversion in humans was in the same range as obtained using the gold standard immunoassays ELISA and Luminex, though requiring only a fraction of consumables, instrumentation, time to deliver results, and volume of sample. Furthermore, the results obtained with the method described can be visually interpreted without compromising accuracy as demonstrated by validation at a point-of-care unit. The magnetic bead immunoassay throughput can be customized on demand and is readily adapted to be used with any other 6xHis tagged protein or peptide as antigen to track other diseases.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing , COVID-19/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , SARS-CoV-2/immunology , COVID-19/blood , COVID-19/immunology , Humans , Immunoglobulin G/immunology , Magnetic Phenomena
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