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Rxivist combines biology preprints from bioRxiv and medRxiv with data from Twitter to help you find the papers being discussed in your field. Currently indexing 212,235 papers from 844,985 authors.

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in category immunology

6,733 results found. For more information, click each entry to expand.

1: A prefusion SARS-CoV-2 spike RNA vaccine is highly immunogenic and prevents lung infection in non-human primates
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Posted 08 Sep 2020

A prefusion SARS-CoV-2 spike RNA vaccine is highly immunogenic and prevents lung infection in non-human primates
94,598 downloads bioRxiv immunology

Annette B. Vogel, Isis Kanevsky, Ye Che, Kena A. Swanson, Alexander Muik, Mathias Vormehr, Lena M Kranz, Kerstin C. Walzer, Stephanie Hein, Alptekin Güler, Jakob Loschko, Mohan S. Maddur, Kristin Tompkins, Journey Cole, Bonny G. Lui, Thomas Ziegenhals, Arianne Plaschke, David Eisel, Sarah C. Dany, Stephanie Fesser, Stephanie Erbar, Ferdia Bates, Diana Schneider, Bernadette Jesionek, Bianca Sänger, Ann-Kathrin Wallisch, Yvonne Feuchter, Hanna Junginger, Stefanie A. Krumm, André P. Heinen, Petra Adams-Quack, Julia Schlereth, Christoph Kröner, Shannan Hall-Ursone, Kathleen Brasky, Matthew C. Griffor, Seungil Han, Joshua A. Lees, Ellene H. Mashalidis, Parag V. Sahasrabudhe, Charles Y. Tan, Danka Pavliakova, Guy Singh, Camila Fontes-Garfias, Michael Pride, Ingrid L. Scully, Tara Ciolino, Jennifer Obregon, Michal Gazi, Ricardo Carrion, Kendra J. Alfson, Warren V. Kalina, Deepak Kaushal, Pei-Yong Shi, Thorsten Klamp, Corinna Rosenbaum, Andreas N. Kuhn, Özlem Türeci, Philip R. Dormitzer, Kathrin U. Jansen, Ugur Sahin

To contain the coronavirus disease 2019 (COVID-19) pandemic, a safe and effective vaccine against the new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is urgently needed in quantities sufficient to immunise large populations. In this study, we report the design, preclinical development, immunogenicity and anti-viral protective effect in rhesus macaques of the BNT162b2 vaccine candidate. BNT162b2 contains an LNP-formulated nucleoside-modified mRNA that encodes the spike glycoprotein captured in its prefusion conformation. After expression of the BNT162b2 coding sequence in cells, approximately 20% of the spike molecules are in the one-RBD ‘up’, two-RBD ‘down’ state. Immunisation of mice with a single dose of BNT162b2 induced dose level-dependent increases in pseudovirus neutralisation titers. Prime-boost vaccination of rhesus macaques elicited authentic SARS-CoV-2 neutralising geometric mean titers 10.2 to 18.0 times that of a SARS-CoV-2 convalescent human serum panel. BNT162b2 generated strong TH1 type CD4+ and IFNγ+ CD8+ T-cell responses in mice and rhesus macaques. The BNT162b2 vaccine candidate fully protected the lungs of immunised rhesus macaques from infectious SARS-CoV-2 challenge. BNT162b2 is currently being evaluated in a global, pivotal Phase 2/3 trial ([NCT04368728][1]). ### Competing Interest Statement U.S. and O.T. are management board members and employees at BioNTech SE (Mainz, Germany); K.C.W., B.G.L., D.S., B.J., T.K. and C.R. are employees at BioNTech SE; A.B.V., A.M., M.V., L.M.K., S.He., A.G., T.Z., A.P., D.E., S.C.D., S.F., S.E., F.B., B.S., A.W., Y.F., H.J., S.A.K., A.P.H., P.A., J.S., C.K., and A.N.K. are employees at BioNTech RNA Pharmaceuticals GmbH (Mainz, Germany); A.B.V., A.M., K.C.W., A.G., S.F., A.N.K and U.S. are inventors on patents and patent applications related to RNA technology and COVID-19 vaccine; A.B.V., A.M., M.V., L.M.K., K.C.W., S.He., B.G.L., A.P., D.E., S.C.D., S.F., S.E., D.S., B.J., B.S., A.P.H., P.A., J.S., C.K., T.K., C.R., A.N.K., O.T. and U.S. have securities from BioNTech SE; I.K., Y.C., K.A.S., J.L., M.M., K.T., M.C.G., S.H., J.A.L.,E.H.M., P.V.S., C.Y.T., D.P., G.S., M.P., I.L.S., T.C., J.O., W.V.K., P.R.D. and K.U.J. are employees of Pfizer and may hold stock options; C.F.-G. and P.-Y.S. received compensation from Pfizer to perform neutralisation assays; J.C., S.H.-U, K.B., R.C., jr., K.J.A. and D.K., are employees of Southwest National Primate Research Center, which received compensation from Pfizer to conduct the animal challenge work; no other relationships or activities that could appear to have influenced the submitted work. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT04368728&atom=%2Fbiorxiv%2Fearly%2F2020%2F09%2F08%2F2020.09.08.280818.atom

2: Robust T cell immunity in convalescent individuals with asymptomatic or mild COVID-19
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Posted 29 Jun 2020

Robust T cell immunity in convalescent individuals with asymptomatic or mild COVID-19
94,418 downloads bioRxiv immunology

Takuya Sekine, André Perez-Potti, Olga Rivera-Ballesteros, Kristoffer Stralin, Jean-Baptiste Gorin, Annika Olsson, Sian Llewellyn-Lacey, Habiba Kamal, Gordana Bogdanovic, Sandra Muschiol, David J. Wullimann, Tobias Kammann, Johanna Emgård, Tiphaine Parrot, Elin Folkesson, Olav Rooyackers, Lars I Eriksson, Anders Sönnerborg, Tobias Allander, Jan Albert, Morten Nielsen, Jonas Klingström, Sara Gredmark-Russ, Niklas K Björkström, Johan K Sandberg, David A. Price, Hans-Gustaf Ljunggren, Soo Aleman, Marcus Buggert, Karolinska COVID-19 Study Group

SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. We systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in a large cohort of unexposed individuals as well as exposed family members and individuals with acute or convalescent COVID-19. Acute phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative family members and individuals with a history of asymptomatic or mild COVID-19. Our collective dataset shows that SARS-CoV-2 elicits robust memory T cell responses akin to those observed in the context of successful vaccines, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19 also in seronegative individuals. ### Competing Interest Statement The authors have declared no competing interest.

3: Immunological memory to SARS-CoV-2 assessed for up to eight months after infection
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Posted 16 Nov 2020

Immunological memory to SARS-CoV-2 assessed for up to eight months after infection
73,106 downloads bioRxiv immunology

Jennifer Dan, Jose Mateus, Yu Kato, Kathryn M Hastie, Esther Dawen Yu, Caterina E. Faliti, Alba Grifoni, Sydney I Ramirez, Sonya Haupt, April Frazier, Catherine Nakao, Vamseedhar Rayaprolu, Stephen A Rawlings, Bjoern Peters, Florian Krammer, Viviana Simon, Erica Ollmann Saphire, Davey Smith, Daniela Weiskopf, Alessandro Sette, Shane Crotty

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.

4: Broadly neutralizing antibodies overcome SARS-CoV-2 Omicron antigenic shift
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Posted 14 Dec 2021

Broadly neutralizing antibodies overcome SARS-CoV-2 Omicron antigenic shift
73,042 downloads bioRxiv immunology

Elisabetta Cameroni, Christian Saliba, John E. Bowen, Laura E. Rosen, Katja Culap, Dora Pinto, Laura A VanBlargan, Anna De Marco, Samantha K Zepeda, Julia di Iulio, Fabrizia Zatta, Hanna Kaiser, Julia Noack, Nisar Farhat, Nadine Czudnochowski, Colin Havenar-Daughton, Kaitlin R. Sprouse, Josh R. Dillen, Abigail E Powell, Alex Chen, Cyrus Maher, Li Yin, David Sun, Leah Soriaga, Jessica Bassi, Chiara Silacci-Fregni, Claes Gustafsson, Helen Chu, Nicholas M. Franko, Jenni Logue, Najeeha Talat Iqbal, Ignacio Mazzitelli, Jorge Geffner, Renata Grifantini, Andrea Gori, Agostino Riva, Olivier Giannini, Alessandro Ceschi, Paolo Ferrari, Alessandra Franzetti-Pellanda, Christian Garzoni, Peter J. Halfmann, Yoshihiro Kawaoka, Christy Hebner, Lisa Purcell, Luca Piccoli, Matteo Samuele Pizzuto, Alexandra C Walls, Michael S. Diamond, Amalio Telenti, Herbert W Virgin, Antonio Lanzavecchia, David Veesler, Gyorgy Snell, Davide Corti

The recently emerged SARS-CoV-2 Omicron variant harbors 37 amino acid substitutions in the spike (S) protein, 15 of which are in the receptor-binding domain (RBD), thereby raising concerns about the effectiveness of available vaccines and antibody therapeutics. Here, we show that the Omicron RBD binds to human ACE2 with enhanced affinity relative to the Wuhan-Hu-1 RBD and acquires binding to mouse ACE2. Severe reductions of plasma neutralizing activity were observed against Omicron compared to the ancestral pseudovirus for vaccinated and convalescent individuals. Most (26 out of 29) receptor-binding motif (RBM)-directed monoclonal antibodies (mAbs) lost in vitro neutralizing activity against Omicron, with only three mAbs, including the ACE2-mimicking S2K146 mAb, retaining unaltered potency. Furthermore, a fraction of broadly neutralizing sarbecovirus mAbs recognizing antigenic sites outside the RBM, including sotrovimab, S2X259 and S2H97, neutralized Omicron. The magnitude of Omicron-mediated immune evasion and the acquisition of binding to mouse ACE2 mark a major SARS-CoV-2 mutational shift. Broadly neutralizing sarbecovirus mAbs recognizing epitopes conserved among SARS-CoV-2 variants and other sarbecoviruses may prove key to controlling the ongoing pandemic and future zoonotic spillovers.

5: mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants
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Posted 19 Jan 2021

mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants
71,549 downloads bioRxiv immunology

Zijun Wang, Fabian Schmidt, Yiska Weisblum, Frauke Muecksch, Christopher O Barnes, Shlomo Finkin, Dennis Schaefer-Babajew, Melissa Cipolla, Christian Gaebler, Jenna A Lieberman, Thiago Y. Oliveira, Zhi Yang, Morgan E. Abernathy, Kathryn E. Huey-Tubman, Arlene Hurley, Martina Turroja, Kamille A West, Kristie Gordon, Katrina G Millard, Victor Ramos, Justin Da Silva, Jianliang Xu, Robert A Colbert, Roshni Patel, Juan P. Dizon, Cecille Unson-O'Brien, Irina Shimeliovich, Anna Gazumyan, Marina Caskey, Pamela J Bjorkman, Rafael Casellas, Theodora Hatziioannou, Paul D. Bieniasz, Michel C. Nussenzweig

To date severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected nearly 100 million individuals resulting in over two million deaths. Many vaccines are being deployed to prevent coronavirus disease-2019 (COVID-19) including two novel mRNA-based vaccines. These vaccines elicit neutralizing antibodies and appear to be safe and effective, but the precise nature of the elicited antibodies is not known. Here we report on the antibody and memory B cell responses in a cohort of 20 volunteers who received either the Moderna (mRNA-1273) or Pfizer-BioNTech (BNT162b2) vaccines. Consistent with prior reports, 8 weeks after the second vaccine injection volunteers showed high levels of IgM, and IgG anti-SARS-CoV-2 spike protein (S), receptor binding domain (RBD) binding titers. Moreover, the plasma neutralizing activity, and the relative numbers of RBD-specific memory B cells were equivalent to individuals who recovered from natural infection. However, activity against SARS-CoV-2 variants encoding E484K or N501Y or the K417N:E484K:N501Y combination was reduced by a small but significant margin. Consistent with these findings, vaccine-elicited monoclonal antibodies (mAbs) potently neutralize SARS-CoV-2, targeting a number of different RBD epitopes epitopes in common with mAbs isolated from infected donors. Structural analyses of mAbs complexed with S trimer suggest that vaccine- and virus-encoded S adopts similar conformations to induce equivalent anti-RBD antibodies. However, neutralization by 14 of the 17 most potent mAbs tested was reduced or abolished by either K417N, or E484K, or N501Y mutations. Notably, the same mutations were selected when recombinant vesicular stomatitis virus (rVSV)/SARS-CoV-2 S was cultured in the presence of the vaccine elicited mAbs. Taken together the results suggest that the monoclonal antibodies in clinical use should be tested against newly arising variants, and that mRNA vaccines may need to be updated periodically to avoid potential loss of clinical efficacy.

6: Comparison of Neutralizing Antibody Titers Elicited by mRNA and Adenoviral Vector Vaccine against SARS-CoV-2 Variants
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Posted 19 Jul 2021

Comparison of Neutralizing Antibody Titers Elicited by mRNA and Adenoviral Vector Vaccine against SARS-CoV-2 Variants
70,940 downloads bioRxiv immunology

Takuya Tada, Hao Zhou, Marie I Samanovic, Belinda M Dcosta, Amber Cornelius, Mark J Mulligan, Nathaniel R Landau

The increasing prevalence of SARS-CoV-2 variants has raised concerns regarding possible decreases in vaccine efficacy. Here, neutralizing antibody titers elicited by mRNA-based and an adenoviral vector-based vaccine against variant pseudotyped viruses were compared. BNT162b2 and mRNA-1273-elicited antibodies showed modest neutralization resistance against Beta, Delta, Delta plus and Lambda variants whereas Ad26.COV2.S-elicited antibodies from a significant fraction of vaccinated individuals were of low neutralizing titer (IC50 <50). The data underscore the importance of surveillance for breakthrough infections that result in severe COVID-19 and suggest the benefit of a second immunization following Ad26.COV2.S to increase protection against the variants.

7: SARS-CoV-2 501Y.V2 escapes neutralization by South African COVID-19 donor plasma
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Posted 19 Jan 2021

SARS-CoV-2 501Y.V2 escapes neutralization by South African COVID-19 donor plasma
57,334 downloads bioRxiv immunology

Constantinos Kurt Wibmer, Frances Ayres, Tandile Hermanus, Mashudu Madzivhandila, Prudence Kgagudi, Bronwen E Lambson, Marion Vermeulen, Karin van den Berg, Theresa Rossouw, Michael Boswell, Veronica Ueckermann, Susan Meiring, Anne von Gottberg, Cheryl Cohen, Lynn Morris, Jinal N Bhiman, Penny Moore

SARS-CoV-2 501Y.V2, a novel lineage of the coronavirus causing COVID-19, contains multiple mutations within two immunodominant domains of the spike protein. Here we show that this lineage exhibits complete escape from three classes of therapeutically relevant monoclonal antibodies. Furthermore 501Y.V2 shows substantial or complete escape from neutralizing antibodies in COVID-19 convalescent plasma. These data highlight the prospect of reinfection with antigenically distinct variants and may foreshadow reduced efficacy of current spike-based vaccines.

8: Potent human neutralizing antibodies elicited by SARS-CoV-2 infection
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Posted 25 Mar 2020

Potent human neutralizing antibodies elicited by SARS-CoV-2 infection
44,722 downloads bioRxiv immunology

Bin Ju, Qi Zhang, Xiangyang Ge, Ruoke Wang, Jiazhen Yu, Sisi Shan, Bing Zhou, Shuo Song, Xian Tang, Jinfang Yu, Jiwan Ge, Jun Lan, Jing Yuan, Haiyan Wang, Juanjuan Zhao, Shuye Zhang, Youchun Wang, Xuanling Shi, Lei Liu, Xinquan Wang, zheng zhang, Linqi Zhang

The pandemic caused by emerging coronavirus SARS-CoV-2 presents a serious global public health emergency in urgent need of prophylactic and therapeutic interventions. SARS-CoV-2 cellular entry depends on binding between the viral Spike protein receptor-binding domain (RBD) and the angiotensin converting enzyme 2 (ACE2) target cell receptor. Here, we report on the isolation and characterization of 206 RBD-specific monoclonal antibodies (mAbs) derived from single B cells of eight SARS-CoV-2 infected individuals. These mAbs come from diverse families of antibody heavy and light chains without apparent enrichment for particular families in the repertoire. In samples from one patient selected for further analyses, we found coexistence of germline and germline divergent clones. Both clone types demonstrated impressive binding and neutralizing activity against pseudovirus and live SARS-CoV-2. However, the antibody neutralizing potency is determined by competition with ACE2 receptor for RBD binding. Surprisingly, none of the SARS-CoV-2 antibodies nor the infected plasma cross-reacted with RBDs from either SARS-CoV or MERS-CoV although substantial plasma cross-reactivity to the trimeric Spike proteins from SARS-CoV and MERS-CoV was found. These results suggest that antibody response to RBDs is viral species-specific while that cross-recognition target regions outside the RBD. The specificity and neutralizing characteristics of this plasma cross-reactivity requires further investigation. Nevertheless, the diverse and potent neutralizing antibodies identified here are promising candidates for prophylactic and therapeutic SARS-CoV-2 interventions.

9: Different pattern of pre-existing SARS-COV-2 specific T cell immunity in SARS-recovered and uninfected individuals
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Posted 27 May 2020

Different pattern of pre-existing SARS-COV-2 specific T cell immunity in SARS-recovered and uninfected individuals
44,146 downloads bioRxiv immunology

Nina Le Bert, Anthony T Tan, Kamini Kunasegaran, Christine Y. L. Tham, Morteza Hafezi, Adeline Chia, Melissa Chng, Meiyin Lin, Nicole Tan, Martin Linster, Wan Ni Chia, Mark I-Cheng Chen, Lin-Fa Wang, Eng Eong Ooi, Shirin Kalimuddin, Paul Anantharajal Tambyah, Jenny Guek-Hong Low, Yee-Joo Tan, Antonio Bertoletti

Memory T cells induced by previous infections can influence the course of new viral infections. Little is known about the pattern of SARS-CoV-2 specific pre-existing memory T cells in human. Here, we first studied T cell responses to structural (nucleocapsid protein, NP) and non-structural (NSP-7 and NSP13 of ORF1) regions of SARS-CoV-2 in convalescent from COVID-19 (n=24). In all of them we demonstrated the presence of CD4 and CD8 T cells recognizing multiple regions of the NP protein. We then show that SARS-recovered patients (n=23), 17 years after the 2003 outbreak, still possess long-lasting memory T cells reactive to SARS-NP, which displayed robust cross-reactivity to SARS-CoV-2 NP. Surprisingly, we observed a differential pattern of SARS-CoV-2 specific T cell immunodominance in individuals with no history of SARS, COVID-19 or contact with SARS/COVID-19 patients (n=18). Half of them (9/18) possess T cells targeting the ORF-1 coded proteins NSP7 and 13, which were rarely detected in COVID-19- and SARS-recovered patients. Epitope characterization of NSP7-specific T cells showed recognition of protein fragments with low homology to "common cold" human coronaviruses but conserved among animal betacoranaviruses. Thus, infection with betacoronaviruses induces strong and long-lasting T cell immunity to the structural protein NP. Understanding how pre-existing ORF-1-specific T cells present in the general population impact susceptibility and pathogenesis of SARS-CoV-2 infection is of paramount importance for the management of the current COVID-19 pandemic. ### Competing Interest Statement A.B. is a cofounder of Lion TCR, a biotech company developing T cell receptors for treatment of virus-related diseases and cancers. None of the other authors has any competing interest related to the study.

10: Antibody Resistance of SARS-CoV-2 Variants B.1.351 and B.1.1.7
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Posted 26 Jan 2021

Antibody Resistance of SARS-CoV-2 Variants B.1.351 and B.1.1.7
43,250 downloads bioRxiv immunology

Pengfei Wang, Manoj S. Nair, Lihong Liu, Sho Iketani, Yang Luo, Yicheng Guo, Maple Wang, Jian Yu, Baoshan Zhang, Peter D Kwong, Barney S Graham, John R Mascola, Jennifer Y Chang, Michael T. Yin, Magdalena E Sobieszczyk, Christos A Kyratsous, Lawrence Shapiro, Zizhang Sheng, Yaoxing Huang, David D Ho

The COVID-19 pandemic has ravaged the globe, and its causative agent, SARS-CoV-2, continues to rage. Prospects of ending this pandemic rest on the development of effective interventions. Single and combination monoclonal antibody (mAb) therapeutics have received emergency use authorization, with more in the pipeline. Furthermore, multiple vaccine constructs have shown promise, including two with ~95% protective efficacy against COVID-19. However, these interventions were directed toward the initial SARS-CoV-2 that emerged in 2019. The recent emergence of new SARS-CoV-2 variants B.1.1.7 in the UK and B.1.351 in South Africa is of concern because of their purported ease of transmission and extensive mutations in the spike protein. We now report that B.1.1.7 is refractory to neutralization by most mAbs to the N-terminal domain (NTD) of spike and relatively resistant to a few mAbs to the receptor-binding domain (RBD). It is not more resistant to convalescent plasma or vaccinee sera. Findings on B.1.351 are more worrisome in that this variant is not only refractory to neutralization by most NTD mAbs but also by multiple individual mAbs to the receptor-binding motif on RBD, largely due to an E484K mutation. Moreover, B.1.351 is markedly more resistant to neutralization by convalescent plasma (9.4 fold) and vaccinee sera (10.3-12.4 fold). B.1.351 and emergent variants with similar spike mutations present new challenges for mAb therapy and threaten the protective efficacy of current vaccines.

11: Distinct SARS-CoV-2 antibody reactivity patterns elicited by natural infection and mRNA Vaccination
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Posted 19 Apr 2021

Distinct SARS-CoV-2 antibody reactivity patterns elicited by natural infection and mRNA Vaccination
39,699 downloads bioRxiv immunology

Rafael Ramiro de Assis, Aarti Jain, Rie Nakajima, Algis Jasinskas, Saahir Khan, Anton Palma, Daniel M Parker, Anthony Chau, Amanda Leung, Christina Grabar, Fjolla Muqolli, Ghali Khalil, Jessica Colin Escobar, Jenny Ventura, Huw Davies, Bruce Albala, Bernadette Boden-Albala, Sebastian Schubl, Philip L Felgner

We analyzed data from two ongoing COVID-19 longitudinal serological surveys in Orange County, CA., between April 2020 and March 2021. A total of 8,476 finger stick blood specimens were collected before and after an aggressive mRNA vaccination campaign. IgG levels were determined using a multiplex antigen microarray containing 10 SARS-CoV-2 antigens, 4 SARS, 3 MERS, 12 Common CoV, and 8 Influenza antigens. Twenty-six percent of 3,347 specimens from unvaccinated Orange County residents in December 2020 were SARS-CoV-2 seropositive. The Ab response was predominantly against nucleocapsid (NP), full length spike and the spike S2 domain. Anti-receptor binding domain (RBD) reactivity was low and there was no cross-reactivity against SARS S1 or SARS RBD. An aggressive mRNA vaccination campaign at the UCI Medical Center started on December 16, 2020 and 6,724 healthcare workers were vaccinated within 3 weeks. Seroprevalence increased from 13% in December to 79% in January, 93% in February and 99% in March. mRNA vaccination induced much higher Ab levels especially against the RBD domain and significant cross-reactivity against SARS RBD and S1 was also observed. Nucleocapsid protein Abs can be used to distinguish individuals in a population of vaccinees to classify those who have been previously infected and those who have not, because nucleocapsid is not in the vaccine. Previously infected individuals developed higher Ab titers to the vaccine than those who have not been previously exposed. These results indicate that mRNA vaccination rapidly induces a much stronger and broader Ab response than SARS-CoV-2 infection.

12: mRNA Vaccination Induces Durable Immune Memory to SARS-CoV-2 with Continued Evolution to Variants of Concern
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Posted 23 Aug 2021

mRNA Vaccination Induces Durable Immune Memory to SARS-CoV-2 with Continued Evolution to Variants of Concern
38,944 downloads bioRxiv immunology

Rishi Raj Goel, Mark M Painter, Sokratis A Apostolidis, Divij Mathew, Wenzhao Meng, Aaron M Rosenfeld, Kendall A Lundgreen, Arnold Reynaldi, David S Khoury, Ajinkya Pattekar, Sigrid Gouma, Leticia Kuri-Cervantes, Philip Hicks, Sarah Dysinger, Amanda Hicks, Harsh Sharma, Sarah Herring, Scott Korte, Amy E. Baxter, Derek A. Oldridge, Josephine R Giles, Madison E. Weirick, Christopher M. McAllister, Moses Awofolaju, Nicole Tanenbaum, Elizabeth M Drapeau, Jeanette Dougherty, Sherea Long, Kurt D'Andrea, Jacob T. Hamilton, Maura McLaughlin, Justine C Williams, Sharon Adamski, The UPenn COVID Processing Unit, Oliva Kuthuru, Ian Frank, Michael R. Betts, Laura A. Vella, Alba Grifoni, Daniela Weiskopf, Alessandro Sette, Scott E. Hensley, Miles Philip Davenport, Paul Bates, Eline T Luning Prak, Allison R. Greenplate, E John Wherry

SARS-CoV-2 mRNA vaccines have shown remarkable efficacy, especially in preventing severe illness and hospitalization. However, the emergence of several variants of concern and reports of declining antibody levels have raised uncertainty about the durability of immune memory following vaccination. In this study, we longitudinally profiled both antibody and cellular immune responses in SARS-CoV-2 naive and recovered individuals from pre-vaccine baseline to 6 months post-mRNA vaccination. Antibody and neutralizing titers decayed from peak levels but remained detectable in all subjects at 6 months post-vaccination. Functional memory B cell responses, including those specific for the receptor binding domain (RBD) of the Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2) variants, were also efficiently generated by mRNA vaccination and continued to increase in frequency between 3 and 6 months post-vaccination. Notably, most memory B cells induced by mRNA vaccines were capable of cross-binding variants of concern, and B cell receptor sequencing revealed significantly more hypermutation in these RBD variant-binding clones compared to clones that exclusively bound wild-type RBD. Moreover, the percent of variant cross-binding memory B cells was higher in vaccinees than individuals who recovered from mild COVID-19. mRNA vaccination also generated antigen-specific CD8+ T cells and durable memory CD4+ T cells in most individuals, with early CD4+ T cell responses correlating with humoral immunity at later timepoints. These findings demonstrate robust, multi-component humoral and cellular immune memory to SARS-CoV-2 and current variants of concern for at least 6 months after mRNA vaccination. Finally, we observed that boosting of pre-existing immunity with mRNA vaccination in SARS-CoV-2 recovered individuals primarily increased antibody responses in the short-term without significantly altering antibody decay rates or long-term B and T cell memory. Together, this study provides insights into the generation and evolution of vaccine-induced immunity to SARS-CoV-2, including variants of concern, and has implications for future booster strategies.

13: SARS-CoV-2 mRNA Vaccine Development Enabled by Prototype Pathogen Preparedness
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Posted 11 Jun 2020

SARS-CoV-2 mRNA Vaccine Development Enabled by Prototype Pathogen Preparedness
37,755 downloads bioRxiv immunology

Kizzmekia S. Corbett, Darin Edwards, Sarah R. Leist, Olubukola M. Abiona, Seyhan Boyoglu-Barnum, Rebecca A Gillespie, Sunny Himansu, Alexandra Schäfer, Cynthia T. Ziwawo, Anthony T. DiPiazza, Kenneth H. Dinnon, Sayda M. Elbashir, Christine A. Shaw, Angela Woods, Ethan J Fritch, David R. Martinez, Kevin W. Bock, Mahnaz Minai, Bianca M. Nagata, Geoffrey B. Hutchinson, Kapil Bahl, Dario Garcia-Dominguez, LingZhi Ma, Isabella Renzi, Wing-Pui Kong, Stephen D. Schmidt, Lingshu Wang, Yi Zhang, Laura J Stevens, Emily Phung, Lauren A. Chang, Rebecca J. Loomis, Nedim Emil Altaras, Elisabeth Narayanan, Mihir Metkar, Vlad Presnyak, Catherine Liu, Mark K. Louder, Wei Shi, Kwanyee Leung, Eun Sung Yang, Ande West, Kendra L Gully, Nianshuang Wang, Daniel Wrapp, Nicole A. Doria-Rose, Guillaume Stewart-Jones, Hamilton Bennett, Martha C. Nason, Tracy J. Ruckwardt, Jason S. McLellan, Mark R. Denison, James D. Chappell, Ian N Moore, Kaitlyn M. Morabito, John R Mascola, Ralph S Baric, Andrea Carfi, Barney S Graham

A SARS-CoV-2 vaccine is needed to control the global COVID-19 public health crisis. Atomic-level structures directed the application of prefusion-stabilizing mutations that improved expression and immunogenicity of betacoronavirus spike proteins. Using this established immunogen design, the release of SARS-CoV-2 sequences triggered immediate rapid manufacturing of an mRNA vaccine expressing the prefusion-stabilized SARS-CoV-2 spike trimer (mRNA-1273). Here, we show that mRNA-1273 induces both potent neutralizing antibody and CD8 T cell responses and protects against SARS-CoV-2 infection in lungs and noses of mice without evidence of immunopathology. mRNA-1273 is currently in a Phase 2 clinical trial with a trajectory towards Phase 3 efficacy evaluation. ### Competing Interest Statement K.S.C., N.W., J.S.M., and B.S.G. are inventors on International Patent Application No. WO/2018/081318 entitled Prefusion Coronavirus Spike Proteins and Their Use. K.S.C., O.M.A., G.B.H., N.W., D.W., J.S.M, and B.S.G. are inventors on US Patent Application No. 62/972,886 entitled 2019-nCoV Vaccine. R.S.B. filed an invention report for the SARS-CoV-2 MA virus (UNC ref. #18752).

14: Safety and Potency of COVIran Barekat Inactivated Vaccine Candidate for SARS-CoV-2: A Preclinical Study
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Posted 10 Jun 2021

Safety and Potency of COVIran Barekat Inactivated Vaccine Candidate for SARS-CoV-2: A Preclinical Study
36,914 downloads bioRxiv immunology

Asghar Abdoli, Reza Aalizadeh, Hossein Aminianfar

There is an urgent demand to manufacture an effective and safe vaccine to prevent SARS-CoV2 infection, which resulted in a global pandemic. In this study, we developed an inactivated whole-virus SARS-CoV-2 candidate vaccine named COVIran Barekat. Immunization at two different doses (3 microgram or 5 microgram per dose) elicited a high level of SARS-CoV-2 specific neutralizing antibodies in mice, rabbits, and non-human primates. The results show the safety profile in studied animals (include guinea pig, rabbit, mice, and monkeys). Rhesus macaques were immunized with the two-dose of 5 microgram and microgram of the COVIran Barekat vaccine and showed highly efficient protection against 104 TCID50 of SARS-CoV-2 intratracheal challenge compared with the control group. These results highlight the COVIran Barekat vaccine as a potential candidate to induce a strong and potent immune response which may be a promising and feasible vaccine to protect against SARS-CoV2 infection.

15: Neutralization of variant under investigation B.1.617 with sera of BBV152 vaccinees
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Posted 23 Apr 2021

Neutralization of variant under investigation B.1.617 with sera of BBV152 vaccinees
35,958 downloads bioRxiv immunology

Pragya D Yadav, Gajanan N Sapkal, Priya Abraham, Raches Ella, Gururaj Deshpande, Deepak Y Patil, Dimpal Nyayanit, Nivedita Gupta, Rima R Sahay, Anita M Shete, Samiran Panda, Balram Bhargava, V Krishna Mohan

The drastic rise in the number of cases in Maharashtra, India has created a matter of concern for public health experts. Twelve isolates of VUI lineage B.1.617 were propagated in VeroCCL81 cells and characterized. Convalescent sera of the COVID-19 cases and recipients of BBV152 (Covaxin) were able to neutralize VUI B.1.617.

16: Identification of Pre-Existing Adaptive Immunity to Cas9 Proteins in Humans
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Posted 05 Jan 2018

Identification of Pre-Existing Adaptive Immunity to Cas9 Proteins in Humans
35,928 downloads bioRxiv immunology

Carsten T. Charlesworth, Priyanka S Deshpande, Daniel P Dever, Beruh Dejene, Natalia Gomez-Ospina, Sruthi Mantri, Mara Pavel-Dinu, Joab Camarena, Kenneth I Weinberg, Matthew H. Porteus

The CRISPR-Cas9 system has proven to be a powerful tool for genome editing allowing for the precise modification of specific DNA sequences within a cell. Many efforts are currently underway to use the CRISPR-Cas9 system for the therapeutic correction of human genetic diseases. The most widely used homologs of the Cas9 protein are derived from the bacteria Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes). Based on the fact that these two bacterial species cause infections in the human population at high frequencies, we looked for the presence of pre-existing adaptive immune responses to their respective Cas9 homologs, SaCas9 (S. aureus homolog of Cas9) and SpCas9 (S. pyogenes homolog of Cas9). To determine the presence of anti-Cas9 antibodies, we probed for the two homologs using human serum and were able to detect antibodies against both, with 79% of donors staining against SaCas9 and 65% of donors staining against SpCas9. Upon investigating the presence of antigen-specific T-cells against the two homologs in human peripheral blood, we found anti-SaCas9 T-cells in 46% of donors. Upon isolating, expanding, and conducting antigen re-stimulation experiments on several of these donors anti-SaCas9 T-cells, we observed a SaCas9-specific response confirming that these T-cells were antigen-specific. We were unable to detect antigen-specific T-cells against SpCas9, although the sensitivity of the assay precludes us from concluding that such T-cells do not exist. Together, this data demonstrates that there are pre-existing humoral and cell-mediated adaptive immune responses to Cas9 in humans, a factor which must be taken into account as the CRISPR-Cas9 system moves forward into clinical trials.

17: Evolution of Antibody Immunity to SARS-CoV-2
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Posted 05 Nov 2020

Evolution of Antibody Immunity to SARS-CoV-2
33,878 downloads bioRxiv immunology

Christian Gaebler, Zijun Wang, Julio C. C. Lorenzi, Frauke Muecksch, Shlomo Finkin, Minami Tokuyama, Alice Cho, Mila Jankovic, Dennis Schaefer-Babajew, Thiago Y. Oliveira, Melissa Cipolla, Charlotte Viant, Christopher O Barnes, Yaron Bram, Gaëlle Breton, Thomas Hägglöf, Pilar Mendoza, Arlene Hurley, Martina Turroja, Kristie Gordon, Katrina G Millard, Victor Ramos, Fabian Schmidt, Yiska Weisblum, Divya Jha, Michael Tankelevich, Gustavo Martinez-Delgado, Jim Yee, Roshni Patel, Juan Dizon, Cecille Unson-O’Brien, Irina Shimeliovich, Davide F. Robbiani, Zhen Zhao, Anna Gazumyan, Robert E. Schwartz, Theodora Hatziioannou, Pamela J Bjorkman, Saurabh Mehandru, Paul D. Bieniasz, Marina Caskey, Michel C. Nussenzweig

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected 78 million individuals and is responsible for over 1.7 million deaths to date. Infection is associated with development of variable levels of antibodies with neutralizing activity that can protect against infection in animal models. Antibody levels decrease with time, but the nature and quality of the memory B cells that would be called upon to produce antibodies upon re-infection has not been examined. Here we report on the humoral memory response in a cohort of 87 individuals assessed at 1.3 and 6.2 months after infection. We find that IgM, and IgG anti-SARS-CoV-2 spike protein receptor binding domain (RBD) antibody titers decrease significantly with IgA being less affected. Concurrently, neutralizing activity in plasma decreases by five-fold in pseudotype virus assays. In contrast, the number of RBD-specific memory B cells is unchanged. Memory B cells display clonal turnover after 6.2 months, and the antibodies they express have greater somatic hypermutation, increased potency and resistance to RBD mutations, indicative of continued evolution of the humoral response. Analysis of intestinal biopsies obtained from asymptomatic individuals 4 months after coronavirus disease-2019 (COVID-19) onset, using immunofluorescence, or polymerase chain reaction, revealed persistence of SARS-CoV-2 nucleic acids and immunoreactivity in the small bowel of 7 out of 14 volunteers. We conclude that the memory B cell response to SARS-CoV-2 evolves between 1.3 and 6.2 months after infection in a manner that is consistent with antigen persistence.

18: SARS-CoV-2 escape in vitro from a highly neutralizing COVID-19 convalescent plasma
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Posted 28 Dec 2020

SARS-CoV-2 escape in vitro from a highly neutralizing COVID-19 convalescent plasma
32,965 downloads bioRxiv immunology

Emanuele Andreano, Giulia Piccini, Danilo Licastro, Lorenzo Casalino, Nicole V Johnson, Ida Paciello, Simeone Dal Monego, Elisa Pantano, Noemi Manganaro, Alessandro Manenti, Rachele Manna, Elisa Casa, Inesa Hyseni, Linda Benincasa, Emanuele Montomoli, Rommie E Amaro, Jason S McLellan, Rino Rappuoli

To investigate the evolution of SARS-CoV-2 in the immune population, we co-incubated authentic virus with a highly neutralizing plasma from a COVID-19 convalescent patient. The plasma fully neutralized the virus for 7 passages, but after 45 days, the deletion of F140 in the spike N-terminal domain (NTD) N3 loop led to partial breakthrough. At day 73, an E484K substitution in the receptor-binding domain (RBD) occurred, followed at day 80 by an insertion in the NTD N5 loop containing a new glycan sequon, which generated a variant completely resistant to plasma neutralization. Computational modeling predicts that the deletion and insertion in loops N3 and N5 prevent binding of neutralizing antibodies. The recent emergence in the United Kingdom and South Africa of natural variants with similar changes suggests that SARS-CoV-2 has the potential to escape an effective immune response and that vaccines and antibodies able to control emerging variants should be developed. One Sentence SummaryThree mutations allowed SARS-CoV-2 to evade the polyclonal antibody response of a highly neutralizing COVID-19 convalescent plasma.

19: mRNA-1273 or mRNA-Omicron boost in vaccinated macaques elicits comparable B cell expansion, neutralizing antibodies and protection against Omicron
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Posted 04 Feb 2022

mRNA-1273 or mRNA-Omicron boost in vaccinated macaques elicits comparable B cell expansion, neutralizing antibodies and protection against Omicron
32,407 downloads bioRxiv immunology

Matthew Gagne, Juan I. Moliva, Kathryn E. Foulds, Shayne F. Andrew, Barbara J. Flynn, Anne P. Werner, Danielle A. Wagner, I-Ting Teng, Bob C Lin, Christopher Moore, Nazaire Jean-Baptiste, Robin Carroll, Stephanie L Foster, Mit Patel, Madison Ellis, Venkata-Viswanadh Edara, Nahara Vargas Maldonado, Mahnaz Minai, Lauren McCormick, Christopher Cole Honeycutt, Bianca M. Nagata, Kevin W. Bock, Caitlyn N. M. Dulan, Jamilet Cordon, John-Paul M. Todd, Elizabeth McCarthy, Laurent Pessaint, Alex Van Ry, Brandon Narvaez, Daniel Valentin, Anthony Cook, Alan Dodson, Katelyn Steingrebe, Dillon R. Flebbe, Saule T. Nurmukhambetova, Sucheta Godbole, Amy R Henry, Farida Laboune, Jesmine Roberts-Torres, Cynthia G. Lorang, Shivani Amin, Jessica Trost, Mursal Naisan, Manjula Basappa, Jacquelyn Willis, Lingshu Wang, Wei Shi, Nicole A. Doria-Rose, Adam S. Olia, Cuiping Liu, Darcy R. Harris, Andrea Carfi, John R. Mascola, Peter D Kwong, Darin K Edwards, Hanne Andersen, Mark G. Lewis, Kizzmekia S. Corbett, Martha C. Nason, Adrian B. McDermott, Mehul S Suthar, Ian N Moore, Mario Roederer, Nancy J Sullivan, Daniel C Douek, Robert A. Seder

SARS-CoV-2 Omicron is highly transmissible and has substantial resistance to antibody neutralization following immunization with ancestral spike-matched vaccines. It is unclear whether boosting with Omicron-specific vaccines would enhance immunity and protection. Here, nonhuman primates that received mRNA-1273 at weeks 0 and 4 were boosted at week 41 with mRNA-1273 or mRNA-Omicron. Neutralizing antibody titers against D614G were 4760 and 270 reciprocal ID50 at week 6 (peak) and week 41 (pre-boost), respectively, and 320 and 110 for Omicron. Two weeks after boost, titers against D614G and Omicron increased to 5360 and 2980, respectively, for mRNA-1273 and 2670 and 1930 for mRNA-Omicron. Following either boost, 70-80% of spike-specific B cells were cross-reactive against both WA1 and Omicron. Significant and equivalent control of virus replication in lower airways was observed following either boost. Therefore, an Omicron boost may not provide greater immunity or protection compared to a boost with the current mRNA-1273 vaccine.

20: Negligible impact of SARS-CoV-2 variants on CD4+ and CD8+ T cell reactivity in COVID-19 exposed donors and vaccinees.
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Posted 01 Mar 2021

Negligible impact of SARS-CoV-2 variants on CD4+ and CD8+ T cell reactivity in COVID-19 exposed donors and vaccinees.
30,011 downloads bioRxiv immunology

Alison Tarke, John Sidney, Nils Methot, Yun R Zhang, Benjamin Goodwin, Paul Rubiro, Aaron Sutherland, Ricardo da Silva Antunes, April Frazier, Stephen A Rawlings, Davey Smith, Bjoern Peters, Richard H Scheuermann, Daniela Weiskopf, Shane Crotty, Alba Grifoni, Alessandro Sette

The emergence of SARS-CoV-2 variants highlighted the need to better understand adaptive immune responses to this virus. It is important to address whether also CD4+ and CD8+ T cell responses are affected, because of the role they play in disease resolution and modulation of COVID-19 disease severity. Here we performed a comprehensive analysis of SARS-CoV-2-specific CD4+ and CD8+ T cell responses from COVID-19 convalescent subjects recognizing the ancestral strain, compared to variant lineages B.1.1.7, B.1.351, P.1, and CAL.20C as well as recipients of the Moderna (mRNA-1273) or Pfizer/BioNTech (BNT162b2) COVID-19 vaccines. Similarly, we demonstrate that the sequences of the vast majority of SARS-CoV-2 T cell epitopes are not affected by the mutations found in the variants analyzed. Overall, the results demonstrate that CD4+ and CD8+ T cell responses in convalescent COVID-19 subjects or COVID-19 mRNA vaccinees are not substantially affected by mutations found in the SARS-CoV-2 variants.

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