ABSTRACT
Despite the remarkable success of SARS CoV-2 vaccines, the rise of variants, some of which are more resistant to the effects of vaccination, highlights the potential need for additional COVID-19 vaccines. We used the Multiple Antigen Presenting System (MAPS) technology, in which proteins are presented on a polysaccharide polymer to induce antibody, Th1, Th17 and CD8+ T cell responses, to engineer a novel vaccine targeting SARS CoV-2. This vaccine contains a fragment of the spike (S) protein receptor-binding domain (RBD) sequence of the original D614G strain and was used to immunize nonhuman primates (NHP) for assessment of immunological responses and protection against SARS CoV-2 challenge. The SARS CoV-2 MAPS vaccine generated robust neutralizing antibodies as well as Th1, Th17 and cytotoxic CD8 T-cell responses in NHPs. Furthermore, MAPS-immunized NHPs had significantly lower viral loads in the nasopharynx and lung compared to control animals. Taken together, these findings support the use of the MAPS platform to make a SARS CoV-2 vaccine. The nature of the platform also could enable its use for the inclusion of different variants in a single vaccine.
Subject(s)
COVID-19ABSTRACT
Importance: Emergent SARS-CoV-2 variants and waning humoral immunity in vaccinated individuals are causing increased infections and hospitalizations. Children are not spared from infection nor complications of COVID-19, and the recent recommendation for boosters in individuals ages 12 years or older calls for broader understanding of the adolescent immune profile after mRNA vaccination. Objective: We sought to test the durability and cross-reactivity of anti-SARS-CoV-2 serologic responses over a six-month time course in vaccinated adolescents against the wildtype and Omicron antigens. Design, Setting and Participants: Adolescents who received a full (two-dose) series of the Pfizer-BioNTech mRNA vaccination participated in this longitudinal cohort study from May 2021 to January 2022. Blood samples were collected in clinical settings from thirty-one adolescents, nineteen of whom provided samples at four timepoints (prior to vaccination, two to three weeks after first dose, two to four weeks after second dose and six months after complete series). Sera were analyzed for antibody responses against wildtype and Omicron variant SARS-CoV-2-specific proteins. Main Outcomes and Measures: The main outcome was to analyze vaccine-induced immune responses over time by ELISA, as well as their cross-reactivity between antibody responses against wildtype SARS-CoV-2 and the Omicron variant of concern. Results: Thirty-one adolescents provided a blood sample for at least one timepoint. The median age of the cohort was 13.9 years. Half of the cohort was male, and one quarter of the population was Hispanic. Anti-Spike and anti-RBD antibodies waned after six months, nearing pre-vaccination levels. After the second dose of the vaccine, adolescent children displayed equal sensitivity for the Omicron-RBD and wildtype SARS-CoV-2-RBD, as well as an upward trend of Omicron-reactive antibodies six months after vaccination. Waning mRNA vaccine-induced immunity in adolescents highlights a vulnerability in pediatric protection against SARS-CoV-2 infection. Conclusions and Relevance: Vaccine-induced immunity wanes in adolescents over time to near pre-vaccinated levels. Cross-reactivity of antibodies generated by adolescents display efficacy against Omicron. These findings highlight the need for SARS-CoV-2 boosters to protect adolescents from highly infectious variants, illness and post-COVID-19 complications.
Subject(s)
COVID-19 , Severe Acute Respiratory SyndromeABSTRACT
Multisystem Inflammatory Syndrome in Children (MIS-C) is a delayed-onset, COVID-19-related hyperinflammatory systemic illness characterized by SARS-CoV-2 antigenemia, cytokine storm and immune dysregulation; however, the role of the neutrophil has yet to be defined. In adults with severe COVID-19, neutrophil activation has been shown to be central to overactive inflammatory responses and complications. Thus, we sought to define neutrophil activation in children with MIS-C and acute COVID-19. We collected samples from 141 children: 31 cases of MIS-C, 43 cases of acute pediatric COVID-19, and 67 pediatric controls. We found that MIS-C neutrophils display a granulocytic myeloid-derived suppressor cell (G-MDSC) signature with highly altered metabolism, which is markedly different than the neutrophil interferon-stimulated gene (ISG) response observed in pediatric patients during acute SARS-CoV-2 infection. Moreover, we identified signatures of neutrophil activation and degranulation with high levels of spontaneous neutrophil extracellular trap (NET) formation in neutrophils isolated from fresh whole blood of MIS-C patients. Mechanistically, we determined that SARS-CoV-2 immune complexes are sufficient to trigger NETosis. Overall, our findings suggest that the hyperinflammatory presentation of MIS-C could be mechanistically linked to persistent SARS-CoV-2 antigenemia through uncontrolled neutrophil activation and NET release in the vasculature. One Sentence Summary Circulating SARS-CoV-2 antigen:antibody immune complexes in Multisystem Inflammatory Syndrome in Children (MIS-C) drive hyperinflammatory and coagulopathic neutrophil extracellular trap (NET) formation and neutrophil activation pathways, providing insight into disease pathology and establishing a divergence from neutrophil signaling seen in acute pediatric COVID-19.
Subject(s)
Cryopyrin-Associated Periodic Syndromes , COVID-19 , Chronic Disease , Inflammatory Bowel DiseasesABSTRACT
The introduction of vaccines has inspired new hope in the battle against SARS-CoV-2. However, the emergence of viral variants, in the absence of potent antivirals, has left the world struggling with the uncertain nature of this disease. Antibodies currently represent the strongest correlate of immunity against COVID-19, thus we profiled the earliest humoral signatures in a large cohort of severe and asymptomatic COVID-19 individuals. While a SARS-CoV-2-specific immune response evolved rapidly in survivors of COVID-19, non-survivors exhibited blunted and delayed humoral immune evolution, particularly with respect to S2-specific antibody evolution. Given the conservation of S2 across {beta}-coronaviruses, we found the early development of SARS-CoV-2-specific immunity occurred in tandem with pre-existing common {beta}-coronavirus OC43 humoral immunity in survivors, which was selectively also expanded in individuals that develop paucisymptomatic infection. These data point to the importance of cross-coronavirus immunity as a correlate of protection against COVID-19.
Subject(s)
COVID-19ABSTRACT
The robust protection conferred by SARS-CoV-2 mRNA vaccines represents a critical milestone in the COVID-19 vaccine development. However, the emergence of variants has inspired renewed concern related to the protective efficacy of currently approved vaccines, which lose neutralizing potency against some variants. However, emerging data suggest that antibody functions, beyond neutralization, may contribute to protection from disease. Thus, here we profiled the binding and functional capacity of convalescent antibodies and Moderna mRNA-1273 COVID-19 vaccine-induced antibodies across SARS-CoV-2 variants of concern (VOC). While neutralizing antibody responses are affected by VOCs, antibodies generated after infection exhibited robust binding to VOCs but compromised interactions with Fc-receptors. Conversely, vaccine-induced antibodies bound robustly to VOCs and continued interacting with Fc-receptors and mediated antibody effector functions. These data point to a previously unappreciated resilience in the mRNA vaccine-induced humoral immune response that may continue to provide protection from SARS-CoV-2 VOCs independent of neutralization.Trial Registration: This work used samples from the phase 1, dose-escalation, open-labelclinical trial designed to determine the safety, reactogenicity, and immunogenicity of mRNA-1273 (mRNA-1273 ClinicalTrials.gov number, NCT04283461 mRNA-1273 study; DOI: 10.1056/NEJMoa2022483).Funding: We acknowledge support from the Ragon Institute of MGH, MIT, and Harvard, the Massachusetts Consortium on Pathogen Readiness (MassCPR), the NIH (3R37AI080289-11S1, R01AI146785, U19AI42790-01, U19AI135995-02, U19AI42790-01, 1U01CA260476 – 01, CIVIC75N93019C00052), the Gates Foundation Global Health Vaccine Accelerator Platform funding (OPP1146996 and INV-001650), Translational Research Institute for Space Health through NASA Cooperative Agreement (NNX16AO69A), and the Musk Foundation. This work used samples from the phase 1 mRNA-1273 study (NCT04283461; DOI: 10.1056/NEJMoa2022483). The mRNA-1273 phase 1 study was sponsored and primarily funded by the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD. This trial has been funded in part with federal funds from the NIAID under grant awards UM1AI148373, to Kaiser Washington; UM1AI148576, UM1AI148684, and NIH P51 OD011132, to Emory University; NIH AID AI149644, and contract award HHSN272201500002C, to Emmes. Funding for the manufacture of mRNA-1273 phase 1 material was provided by the Coalition for Epidemic Preparedness Innovation.Declaration of Interest: G.A. is a founder of Seromyx Systems Inc. A.C. is employee of Moderna Inc. D.D., P.M., A.S.M, and E.R.M. are employees of Space Exploration Technologies Corp. All other authors have declared that no conflict of interest exists.Ethical Approval: The MGH IRB reviewed the ethics protocol for secondary use under record 2020P004042 and the project was deemed Not Human Research.