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Journal ArticleDOI

SARS-CoV-2 variants of concern partially escape humoral but not T-cell responses in COVID-19 convalescent donors and vaccinees.

TL;DR: In this article, the authors studied humoral and cellular immune responses to wild type SARS-CoV-2 and the B.1.7 and B.351 variants of concern in a cohort of 121 BNT162b2 mRNA-vaccinated health care workers.
Abstract: The emergence of SARS-CoV-2 variants harboring mutations in the spike (S) protein has raised concern about potential immune escape. Here, we studied humoral and cellular immune responses to wild type SARS-CoV-2 and the B.1.1.7 and B.1.351 variants of concern in a cohort of 121 BNT162b2 mRNA-vaccinated health care workers (HCW). Twenty-three HCW recovered from mild COVID-19 disease and exhibited a recall response with high levels of SARS-CoV-2-specific functional antibodies and virus-specific T cells after a single vaccination. Specific immune responses were also detected in seronegative HCW after one vaccination, but a second dose was required to reach high levels of functional antibodies and cellular immune responses in all individuals. Vaccination-induced antibodies cross-neutralized the variants B.1.1.7 and B.1.351, but the neutralizing capacity and Fc-mediated functionality against B.1.351 was consistently 2- to 4-fold lower than to the homologous virus. In addition, peripheral blood mononuclear cells were stimulated with peptide pools spanning the mutated S regions of B.1.1.7 and B.1.351 to detect cross-reactivity of SARS-CoV-2-specific T cells with variants. Importantly, we observed no differences in CD4+ T-cell activation in response to variant antigens, indicating that the B.1.1.7 and B.1.351 S proteins do not escape T-cell-mediated immunity elicited by the wild type S protein. In conclusion, this study shows that some variants can partially escape humoral immunity induced by SARS-CoV-2 infection or BNT162b2 vaccination, but S-specific CD4+ T-cell activation is not affected by the mutations in the B.1.1.7 and B.1.351 variants.
Citations
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Journal ArticleDOI
14 Oct 2021-Science
TL;DR: The durability of immune memory after SARS-CoV-2 mRNA vaccination was investigated in this article, where the majority of these cells cross-binding the Alpha, Beta, and Delta variants.
Abstract: The durability of immune memory after SARS-CoV-2 mRNA vaccination remains unclear. Here, we longitudinally profiled vaccine responses in SARS-CoV-2 naive and recovered individuals for 6 months after vaccination. Antibodies declined from peak levels but remained detectable in most subjects at 6 months. We found mRNA vaccines generated functional memory B cells that increased from 3-6 months post-vaccination, with the majority of these cells cross-binding the Alpha, Beta, and Delta variants. mRNA vaccination further induced antigen-specific CD4+ and CD8+ T cells, and early CD4+ T cell responses correlated with long-term humoral immunity. Recall responses to vaccination in individuals with pre-existing immunity primarily increased antibody levels without substantially altering antibody decay rates. Together, these findings demonstrate robust cellular immune memory to SARS-CoV-2 and variants for at least 6 months after mRNA vaccination.

488 citations

Journal ArticleDOI
01 Jan 2022-Cell
TL;DR: In this paper , the authors address whether T cell responses induced by different vaccine platforms (mRNA-1273, BNT162b2, Ad26.COV2.S, and NVX-CoV2373) cross-recognize early SARS CoV-2 variants.

485 citations

Journal ArticleDOI
TL;DR: In this article, an anti-CD20 monoclonal antibody (aCD20) was used to reduce spike-specific and receptor-binding domain (RBD)-specific antibody and memory B cell responses in most patients.
Abstract: SARS-CoV-2 messenger RNA vaccination in healthy individuals generates immune protection against COVID-19. However, little is known about SARS-CoV-2 mRNA vaccine-induced responses in immunosuppressed patients. We investigated induction of antigen-specific antibody, B cell and T cell responses longitudinally in patients with multiple sclerosis (MS) on anti-CD20 antibody monotherapy (n = 20) compared with healthy controls (n = 10) after BNT162b2 or mRNA-1273 mRNA vaccination. Treatment with anti-CD20 monoclonal antibody (aCD20) significantly reduced spike-specific and receptor-binding domain (RBD)-specific antibody and memory B cell responses in most patients, an effect ameliorated with longer duration from last aCD20 treatment and extent of B cell reconstitution. By contrast, all patients with MS treated with aCD20 generated antigen-specific CD4 and CD8 T cell responses after vaccination. Treatment with aCD20 skewed responses, compromising circulating follicular helper T (TFH) cell responses and augmenting CD8 T cell induction, while preserving type 1 helper T (TH1) cell priming. Patients with MS treated with aCD20 lacking anti-RBD IgG had the most severe defect in circulating TFH responses and more robust CD8 T cell responses. These data define the nature of the SARS-CoV-2 vaccine-induced immune landscape in aCD20-treated patients and provide insights into coordinated mRNA vaccine-induced immune responses in humans. Our findings have implications for clinical decision-making and public health policy for immunosuppressed patients including those treated with aCD20.

320 citations

Journal ArticleDOI
TL;DR: This study shows that vaccinated individuals retain T cell immunity to the SARS-CoV-2 Omicron variant, potentially balancing the lack of neutralizing antibodies in preventing or limiting severe COVID-19 cases.
Abstract: The severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is spreading rapidly, even in vaccinated individuals, raising concerns about immune escape. Here, we studied neutralizing antibodies and T cell responses targeting SARS-CoV-2 D614G [wild type (WT)] and the Beta, Delta, and Omicron variants of concern in a cohort of 60 health care workers after immunization with ChAdOx-1 S, Ad26.COV2.S, mRNA-1273, or BNT162b2. High binding antibody levels against WT SARS-CoV-2 spike (S) were detected 28 days after vaccination with both mRNA vaccines (mRNA-1273 or BNT162b2), which substantially decreased after 6 months. In contrast, antibody levels were lower after Ad26.COV2.S vaccination but did not wane. Neutralization assays showed consistent cross-neutralization of the Beta and Delta variants, but neutralization of Omicron was significantly lower or absent. BNT162b2 booster vaccination after either two mRNA-1273 immunizations or Ad26.COV2 priming partially restored neutralization of the Omicron variant, but responses were still up to 17-fold decreased compared with WT. SARS-CoV-2–specific T cells were detected up to 6 months after all vaccination regimens, with more consistent detection of specific CD4+ than CD8+ T cells. No significant differences were detected between WT- and variant-specific CD4+ or CD8+ T cell responses, including Omicron, indicating minimal escape at the T cell level. This study shows that vaccinated individuals retain T cell immunity to the SARS-CoV-2 Omicron variant, potentially balancing the lack of neutralizing antibodies in preventing or limiting severe COVID-19. Booster vaccinations are needed to further restore Omicron cross-neutralization by antibodies. Description Vaccination-induced SARS-CoV-2–specific CD4+ and CD8+ T cells targeting the ancestral spike protein cross-recognize the Omicron variant. T cells stand strong against Omicron The severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) Omicron variant of concern (VOC) caused an unprecedented rise in COVID-19 cases, even among vaccinated individuals. Omicron has a high number of mutations in the spike protein, probably aiding its evasion of immune responses. GeurtsvanKessel et al. studied humoral and cellular immune responses to Omicron and other VOCs to understand how vaccinated individuals are protected against Omicron. They found that antibody cross-neutralization of Omicron was very low or absent compared with WT, Beta, and Delta variants, but could be partially restored by a third booster vaccination. T cells recognized Omicron just as effectively as other VOCs, suggesting that vaccinated individuals maintain T cell immunity, which could provide protection in the absence of neutralizing antibodies, limiting severe disease.

304 citations

Journal ArticleDOI
Alasdair Munro1, Alasdair Munro2, Leila Janani3, Victoria Cornelius3  +311 moreInstitutions (22)
TL;DR: The COV-BOOST trial as mentioned in this paper investigated the reactogenicity and immunogenicity of seven different COVID-19 vaccines as a third dose after two doses of ChAdOx1 nCov-19 (Oxford-AstraZeneca; hereafter referred to as ChAd) or BNT162b2 (Pfizer-BioNtech, hearafter referred to As BNT).

299 citations

References
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TL;DR: The epidemiological, clinical, laboratory, and radiological characteristics and treatment and clinical outcomes of patients with laboratory-confirmed 2019-nCoV infection in Wuhan, China, were reported.

36,578 citations

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TL;DR: A two-dose regimen of BNT162b2 conferred 95% protection against Covid-19 in persons 16 years of age or older and safety over a median of 2 months was similar to that of other viral vaccines.
Abstract: Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (Covid-19) have afflicted tens of millions of people in a world...

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Journal ArticleDOI
TL;DR: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials.

3,741 citations

Journal ArticleDOI
25 Jun 2020-Cell
TL;DR: Using HLA class I and II predicted peptide ‘megapools’, circulating SARS-CoV-2−specific CD8+ and CD4+ T cells were identified in ∼70% and 100% of COVID-19 convalescent patients, respectively, suggesting cross-reactive T cell recognition between circulating ‘common cold’ coronaviruses and SARS.

3,043 citations

Journal ArticleDOI
TL;DR: The mRNA-1273 vaccine as discussed by the authors is a lipid nanoparticle-encapsulated mRNA-based vaccine that encodes the prefusion stabilized full-length spike protein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes Covid-19.
Abstract: Background Vaccines are needed to prevent coronavirus disease 2019 (Covid-19) and to protect persons who are at high risk for complications. The mRNA-1273 vaccine is a lipid nanoparticle-encapsulated mRNA-based vaccine that encodes the prefusion stabilized full-length spike protein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes Covid-19. Methods This phase 3 randomized, observer-blinded, placebo-controlled trial was conducted at 99 centers across the United States. Persons at high risk for SARS-CoV-2 infection or its complications were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 μg) or placebo 28 days apart. The primary end point was prevention of Covid-19 illness with onset at least 14 days after the second injection in participants who had not previously been infected with SARS-CoV-2. Results The trial enrolled 30,420 volunteers who were randomly assigned in a 1:1 ratio to receive either vaccine or placebo (15,210 participants in each group). More than 96% of participants received both injections, and 2.2% had evidence (serologic, virologic, or both) of SARS-CoV-2 infection at baseline. Symptomatic Covid-19 illness was confirmed in 185 participants in the placebo group (56.5 per 1000 person-years; 95% confidence interval [CI], 48.7 to 65.3) and in 11 participants in the mRNA-1273 group (3.3 per 1000 person-years; 95% CI, 1.7 to 6.0); vaccine efficacy was 94.1% (95% CI, 89.3 to 96.8%; P Conclusions The mRNA-1273 vaccine showed 94.1% efficacy at preventing Covid-19 illness, including severe disease. Aside from transient local and systemic reactions, no safety concerns were identified. (Funded by the Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases; COVE ClinicalTrials.gov number, NCT04470427.).

2,721 citations

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