scholarly journals The kinetic of SARS-CoV-2 antibody (Ab) decline determines the threshold for Ab persistence up to one year

Author(s):  
Erika Garner-Spitzer ◽  
Angelika Wagner ◽  
Michael Kundi ◽  
Hannes Stockinger ◽  
Anna Repic ◽  
...  

Twelve subjects with positive SARS-CoV-2 neutralization test (NT) titers (>1:10) identified in a seroprevalence study with 1655 working adults were followed up for one year. Here we report that 7 of these 12 individuals (58%) still had NT titers ≥1:50, S1-specific IgG concentrations ≥50 BAU/ml and ≥26% ACE2 receptor binding inhibition, measured with surrogate virus NT one year after mild COVID infection. Furthermore, NT_50 titers >1:10 and S1-specific IgG levels >60 BAU/ml present at three months post-infection persisted at detectable levels for 1 year and correlated with circulating S1-specific memory B-cells. Vaccine-induced SARS-CoV2 immune responses decline at similar rates as those after infection; thus the describes threshold of 60 BAU/ml at three months post infection might also be relevant for assessment of Ab persistence after vaccination.

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 729
Author(s):  
Leah E. Cole ◽  
Jinrong Zhang ◽  
Kristl M. Pacheco ◽  
Philippe Lhéritier ◽  
Natalie G. Anosova ◽  
...  

While both whole-cell (wP) and acellular pertussis (aP) vaccines have been highly effective at reducing the global pertussis disease burden, there are concerns that compared to wP vaccination, the immune responses to aP vaccination may wane more rapidly. To gain insights into the vaccine elicited immune responses, pre-adult baboons were immunized with either aP or wP vaccines, boosted with an aP vaccine, and observed over a nearly two-year period. Priming with a wP vaccine elicited a more Th17-biased response than priming with aP, whereas priming with an aP vaccine led to a more Th2-biased response than priming with wP. These differences were maintained after aP vaccine boost immunizations. Compared to aP, animals primed with a wP vaccine exhibited greater numbers of pertussis specific memory B cells. While aP and wP vaccine priming initially elicited similar levels of anti-pertussis toxin antibody, titers declined more rapidly in aP vaccine primed animals leading to a 4-fold difference. Both wP and aP vaccine immunization could induce serum bactericidal activity (SBA); however, only one wP vaccine immunization was required to elicit SBA while multiple aP vaccine immunizations were required to elicit lower, less durable SBA titers. In conclusion, when compared to aP vaccine, priming with wP vaccine elicits distinct cellular and humoral immune responses that persist after aP vaccine boosting.


Author(s):  
Ane Fernandez Salinas ◽  
Eva Piano Mortari ◽  
Sara Terreri ◽  
Concetta Quintarelli ◽  
Federica Pulvirenti ◽  
...  

Abstract Background Data on immune responses to SARS-CoV-2 in patients with Primary Antibody Deficiencies (PAD) are limited to infected patients and to heterogeneous cohorts after immunization. Methods Forty-one patients with Common Variable Immune Deficiencies (CVID), six patients with X-linked Agammaglobulinemia (XLA), and 28 healthy age-matched controls (HD) were analyzed for anti-Spike and anti-receptor binding domain (RBD) antibody production, generation of Spike-specific memory B-cells, and Spike-specific T-cells before vaccination and one week after the second dose of BNT162b2 vaccine. Results The vaccine induced Spike-specific IgG and IgA antibody responses in all HD and in 20% of SARS-CoV-2 naive CVID patients. Anti-Spike IgG were detectable before vaccination in 4 out 7 CVID previously infected with SARS-CoV-2 and were boosted in six out of seven patients by the subsequent immunization raising higher levels than patients naïve to infection. While HD generated Spike-specific memory B-cells, and RBD-specific B-cells, CVID generated Spike-specific atypical B-cells, while RBD-specific B-cells were undetectable in all patients, indicating the incapability to generate this new specificity. Specific T-cell responses were evident in all HD and defective in 30% of CVID. All but one patient with XLA responded by specific T-cell only. Conclusion In PAD patients, early atypical immune responses after BNT162b2 immunization occurred, possibly by extra-follicular or incomplete germinal center reactions. If these responses to vaccination might result in a partial protection from infection or reinfection is now unknown. Our data suggests that SARS-CoV-2 infection more effectively primes the immune response than the immunization alone, possibly suggesting the need for a third vaccine dose for patients not previously infected.


2021 ◽  
Author(s):  
Pablo Garcia-Valtanen ◽  
Christopher Martin Hope ◽  
Makutiro Ghislain Masavuli ◽  
Arthur Eng Lip Yeow ◽  
Harikrishnan Balachandran ◽  
...  

Background The duration and magnitude of SARS-CoV-2 immunity after infection, especially with regard to the emergence of new variants of concern (VoC), remains unclear. Here, immune memory to primary infection and immunity to VoC was assessed in mild-COVID-19 convalescents one year after infection and in the absence of viral re-exposure or COVID-19 vaccination. Methods Serum and PBMC were collected from mild-COVID-19 convalescents at ~6 and 12 months after a COVID-19 positive PCR (n=43) and from healthy SARS-CoV-2-seronegative controls (n=15-40). Serum titers of RBD and Spike-specific Ig were quantified by ELISA. Virus neutralisation was assessed against homologous, pseudotyped virus and homologous and VoC live viruses. Frequencies of Spike and RBD-specific memory B cells were quantified by flow cytometry. Magnitude of memory T cell responses was quantified and phenotyped by activation-induced marker assay, while T cell functionality was assessed by intracellular cytokine staining using peptides specific to homologous Spike virus antigen and four VoC Spike antigens. Findings At 12 months after mild-COVID-19, >90% of convalescents remained seropositive for RBD-IgG and 88.9% had circulating RBD-specific memory B cells. Despite this, only 51.2% convalescents had serum neutralising activity against homologous live-SARS-CoV-2 virus, which decreased to 44.2% when tested against live B.1.1.7, 4.6% against B.1.351, 11.6% against P.1 and 16.2%, against B.1.617.2 VoC. Spike and non-Spike-specific T cells were detected in >50% of convalescents with frequency values higher for Spike antigen (95% CI, 0.29-0.68% in CD4+ and 0.11-0.35% in CD8+ T cells), compared to non-Spike antigens. Despite the high prevalence and maintenance of Spike-specific T cells in Spike 'high-responder' convalescents at 12 months, T cell functionality, measured by cytokine expression after stimulation with Spike epitopes corresponding to VoC was severely affected. Interpretations SARS-CoV-2 immunity is retained in a significant proportion of mild COVID-19 convalescents 12 months post-infection in the absence of re-exposure to the virus. Despite this, changes in the amino acid sequence of the Spike antigen that are present in current VoC result in virus evasion of neutralising antibodies, as well as evasion of functional T cell responses.


2012 ◽  
Vol 19 (6) ◽  
pp. 842-848 ◽  
Author(s):  
Sweta M. Patel ◽  
Mohammad Arif Rahman ◽  
M. Mohasin ◽  
M. Asrafuzzaman Riyadh ◽  
Daniel T. Leung ◽  
...  

ABSTRACTVibrio choleraeO1 causes cholera, a dehydrating diarrheal disease. We have previously shown thatV. cholerae-specific memory B cell responses develop after cholera infection, and we hypothesize that these mediate long-term protective immunity against cholera. We prospectively followed household contacts of cholera patients to determine whether the presence of circulatingV. choleraeO1 antigen-specific memory B cells on enrollment was associated with protection againstV. choleraeinfection over a 30-day period. Two hundred thirty-six household contacts of 122 index patients with cholera were enrolled. The presence of lipopolysaccharide (LPS)-specific IgG memory B cells in peripheral blood on study entry was associated with a 68% decrease in the risk of infection in household contacts (P= 0.032). No protection was associated with cholera toxin B subunit (CtxB)-specific memory B cells or IgA memory B cells specific to LPS. These results suggest that LPS-specific IgG memory B cells may be important in protection against infection withV. choleraeO1.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5087-5087
Author(s):  
Yanran Cao ◽  
Sacha Gnjatic ◽  
Vincent G. Brichard ◽  
Tim Luetkens ◽  
Sebastian Kobold ◽  
...  

Abstract Abstract 5087 Background: Cancer-testis antigens (CTA) are attractive targets for cancer immunotherapy based on their tumor-restricted expression and immunogenicity. A number of CTA, including Melanoma-associated antigen 3 (MAGE-A3), are already under clinical investigation and CTA have been shown to induce strong T cell and humoral immunity in cancer patients receiving active immunotherapy. However, little is known about the fine specificity and the function of vaccine-induced humoral immune responses and it is unclear how they relate to spontaneous CTA-specific immune responses occurring in a minority of patients. Methods: We have performed a longitudinal analysis of spontaneously occurring antibody responses against the CT antigen MAGE-A3 in sera (N=1537), which were collected from patients with multiple myeloma (N=355) over a period of 6 years. Antibody titers were determined by ELISA technique and a B cell ELISPOT assay was applied to estimate the number of MAGEA3-specific memory B cells in peripheral blood of the patients. Fine specificity of the antibody responses was examined using overlapping 20mer peptides spanning the whole sequence of MAGE-A3. The given IgG subtype was determined, and the quality of MAGE-A3-specific antibodies was analyzed using western blot as well as affinity assays. Results were compared to those obtained with MAGE-A3-specific antibody responses induced by vaccination with full-length MAGE-A3 protein and adjuvants AS02B or AS15 in patients with non-small cell lung cancer (NSCLC; N=15). Results: Out of 355 myeloma patients 4 (1.1%) evidenced spontaneous antibody responses against MAGE-A3 at least at one point during the course of their disease. Spontaneously occurring anti-MAGE-A3 humoral responses were usually of low titer. In contrast, all of the vaccinated patients showed high-titered and persisting antibody responses which usually appeared around week 6 after the first application of the vaccine. Accordingly, we found high frequencies of vaccine-induced MAGE-A3-specific memory B cells in the peripheral blood of NSCLC patients while they remained undetectable in most myeloma patients. Vaccine-induced antibody responses underwent affinity maturation reaching affinity levels of spontaneous immune responses after repeated cycles of treatment. MAGE-A3-specific antibodies consisted of IgG1 and IgG3>IgG2>IgG4 subtypes in vaccinated patients whereas spontaneously occurring antibodies were mainly of the IgG2 subtype. Spontaneous as well as vaccine-induced IgG antibodies both recognized the natural full-length protein. Analysis of the fine specificity of the antibody responses revealed that vaccine-induced antibodies recognized a much larger number of MAGE-A3 epitopes than spontaneously occurring antibodies. However, both, spontaneous as well as vaccine-induced responses, most frequently and strongly recognized a specific region within the MAGE-A3 protein corresponding to amino acids 51–70. Conclusions This study demonstrates for the first time important qualitative differences between spontaneously occurring and vaccine-induced antibody responses against the MAGE-A3 antigen in cancer patients. While the potential of both types of antibody responses to promote antigen uptake and induction of T cell responses by antigen-presenting cells might differ, they both recognized the same restricted region within the MAGE-A3 protein. The latter finding might be of importance for the design of future immunotherapies targeting MAGE-A3. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Author(s):  
Pankaj Kumar Mishra ◽  
Natalie Bruiners ◽  
Rahul Ukey ◽  
Pratik Datta ◽  
Alberta Onyuka ◽  
...  

AbstractGiven the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the recent implementation of SARS-CoV-2 vaccination, we have much to learn about the duration of immune protection and the interface between the immune responses to infection and to vaccination. To address these questions, we monitored immune responses to SARS-CoV-2 infection in convalescent individuals over seven months and following mRNA vaccination. Spike Receptor-Binding-Domain (RBD)-specific circulating antibodies and plasma neutralizing activity generally decreased over time, whereas RBD-specific memory B cells persisted. Additionally, using antibody depletion techniques, we showed that the neutralizing activity of plasma specifically resides in the anti-RBD antibodies. More vigorous antibody and B cell responses to vaccination were observed in previously infected subjects relative to uninfected comparators, presumably due to immune priming by infection. SARS-CoV-2 infection also led to increased numbers of double negative B memory cells, which are described as a dysfunctional B cell subset. This effect was reversed by SARS-CoV-2 vaccination, providing a potential mechanistic explanation for the vaccination-induced reduction in symptoms in patients with “Long-COVID”.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261656
Author(s):  
Raphael A. Reyes ◽  
Kathleen Clarke ◽  
S. Jake Gonzales ◽  
Angelene M. Cantwell ◽  
Rolando Garza ◽  
...  

SARS-CoV-2 infection elicits a robust B cell response, resulting in the generation of long-lived plasma cells and memory B cells. Here, we aimed to determine the effect of COVID-19 severity on the memory B cell response and characterize changes in the memory B cell compartment between recovery and five months post-symptom onset. Using high-parameter spectral flow cytometry, we analyzed the phenotype of memory B cells with reactivity against the SARS-CoV-2 spike protein or the spike receptor binding domain (RBD) in recovered individuals who had been hospitalized with non-severe (n = 8) or severe (n = 5) COVID-19. One month after symptom onset, a substantial proportion of spike-specific IgG+ B cells showed an activated phenotype. In individuals who experienced non-severe disease, spike-specific IgG+ B cells showed increased expression of markers associated with durable B cell memory, including T-bet and FcRL5, as compared to individuals who experienced severe disease. While the frequency of T-bet+ spike-specific IgG+ B cells differed between the two groups, these cells predominantly showed an activated switched memory B cell phenotype in both groups. Five months post-symptom onset, the majority of spike-specific memory B cells had a resting phenotype and the percentage of spike-specific T-bet+ IgG+ memory B cells decreased to baseline levels. Collectively, our results highlight subtle differences in the B cells response after non-severe and severe COVID-19 and suggest that the memory B cell response elicited during non-severe COVID-19 may be of higher quality than the response after severe disease.


1985 ◽  
Vol 161 (6) ◽  
pp. 1357-1367 ◽  
Author(s):  
H Braley-Mullen

T cells from CAF1 mice immunized with various amounts of the type 2 antigen polyvinylpyrrolidone (PVP) were assessed for their ability to provide help to PVP-specific memory B cells for the production of IgG. Low doses (0.0025 micrograms) of PVP consistently activated helper T cells (Th), which were required for the production of IgG by primed B cells. In contrast, T cells from mice primed with higher amounts (0.25 or 25 micrograms) of PVP did not provide significant help to the same B cells for IgG production. Moreover, when mixed with B cells and low-dose PVP-primed Th, T cells from mice primed with 0.25 or 25 micrograms PVP suppressed PVP-specific IgG, but not IgM antibody responses. The suppressor cells induced by higher amounts of PVP were eliminated either by injecting cyclophosphamide (CY) before priming with PVP, or by treating the primed T cells with anti-Lyt-2.2 and C before transfer. Pretreatment of suppressor T cell (Ts) donors with CY or removal of Lyt-2+ T cells not only eliminated Ts activity, but also unmasked significant Th activity in the T cells from high-dose PVP-primed mice. Thus, both low and high amounts of PVP can activate Th, although high amounts of PVP also induce Ts, the activity of which predominates in a normal unfractionated T cell population. The amount of PVP (0.0025 micrograms) that induces dominant help for IgG memory responses was only marginally immunogenic for induction of primary PVP-specific IgM responses, while 0.25 and 25 micrograms PVP, which induce dominant suppression for IgG memory responses, are optimally immunogenic for primary IgM responses. These results are discussed in the context of the inability of most type 2 antigens to elicit primary IgG responses or to prime memory B cells for production of IgG, responses which are dependent on the function of antigen-specific Th.


Science ◽  
2021 ◽  
pp. eabf4063
Author(s):  
Jennifer M. Dan ◽  
Jose Mateus ◽  
Yu Kato ◽  
Kathryn M. Hastie ◽  
Esther Dawen Yu ◽  
...  

Understanding immune memory to SARS-CoV-2 is critical for improving diagnostics and vaccines, and for assessing the likely future course of the COVID-19 pandemic. We analyzed multiple compartments of circulating immune memory to SARS-CoV-2 in 254 samples from 188 COVID-19 cases, including 43 samples at ≥ 6 months post-infection. IgG to the Spike protein was relatively stable over 6+ months. Spike-specific memory B cells were more abundant at 6 months than at 1 month post symptom onset. SARS-CoV-2-specific CD4+ T cells and CD8+ T cells declined with a half-life of 3-5 months. By studying antibody, memory B cell, CD4+ T cell, and CD8+ T cell memory to SARS-CoV-2 in an integrated manner, we observed that each component of SARS-CoV-2 immune memory exhibited distinct kinetics.


2021 ◽  
Author(s):  
Zijun Wang ◽  
Frauke Muecksch ◽  
Dennis Schaefer-Babajew ◽  
Shlomo Finkin ◽  
Charlotte Viant ◽  
...  

Over one year after its inception, the coronavirus disease-2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) remains difficult to control despite the availability of several excellent vaccines. Progress in controlling the pandemic is slowed by the emergence of variants that appear to be more transmissible and more resistant to antibodies. Here we report on a cohort of 63 COVID-19-convalescent individuals assessed at 1.3, 6.2 and 12 months after infection, 41% of whom also received mRNA vaccines. In the absence of vaccination antibody reactivity to the receptor binding domain (RBD) of SARS-CoV-2, neutralizing activity and the number of RBD-specific memory B cells remain relatively stable from 6 to 12 months. Vaccination increases all components of the humoral response, and as expected, results in serum neutralizing activities against variants of concern that are comparable to or greater than neutralizing activity against the original Wuhan Hu-1 achieved by vaccination of naive individuals. The mechanism underlying these broad-based responses involves ongoing antibody somatic mutation, memory B cell clonal turnover, and development of monoclonal antibodies that are exceptionally resistant to SARS-CoV-2 RBD mutations, including those found in variants of concern. In addition, B cell clones expressing broad and potent antibodies are selectively retained in the repertoire over time and expand dramatically after vaccination. The data suggest that immunity in convalescent individuals will be very long lasting and that convalescent individuals who receive available mRNA vaccines will produce antibodies and memory B cells that should be protective against circulating SARS-CoV-2 variants. Should memory responses evolve in a similar manner in vaccinated individuals, additional appropriately timed boosting with available vaccines could cover most circulating variants of concern.


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