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1.
J Infect Dis ; 2021 Dec 28.
Article in English | MEDLINE | ID: covidwho-1708333

ABSTRACT

BACKGROUND: Some vaccines elicit non-specific immune responses that may protect against heterologous infections. We evaluated the association between recombinant adjuvanted zoster vaccine (RZV) and COVID-19 outcomes at Kaiser Permanente Southern California. METHODS: In a cohort design, adults aged ≥50 years who received ≥1 RZV dose before 3/1/2020 were matched 1:2 to unvaccinated individuals and followed until 12/31/2020. Adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) for COVID-19 outcomes were estimated using Cox proportional hazards regression. In a test-negative design, cases had a positive SARS-CoV-2 test and controls had only negative tests, during 3/1/2020-12/31/2020. Adjusted odds ratios (aOR) and 95% CIs for RZV receipt were estimated using logistic regression. RESULTS: In the cohort design, 149,244 RZV recipients were matched to 298,488 unvaccinated individuals. The aHRs (95% CI) for COVID-19 diagnosis and hospitalization were 0.84 (0.81-0.87) and 0.68 (0.64-0.74), respectively. In the test-negative design, 8.4% of 75,726 test-positive cases and 13.1% of 340,898 test-negative controls had received ≥1 RZV dose. The aOR (95% CI) was 0.84 (0.81-0.86). CONCLUSION: RZV vaccination was associated with a 16% lower risk of COVID-19 diagnosis and 32% lower risk of hospitalization. Further study of vaccine-induced non-specific immunity for potential attenuation of future pandemics is warranted.

2.
Clin Transl Immunology ; 11(1): e1360, 2022.
Article in English | MEDLINE | ID: covidwho-1619419

ABSTRACT

Objectives: We previously described the Phase I-II evaluation of SARS-CoV-2 recombinant protein candidate vaccine, CoV2-PreS-dTM, with AF03- or AS03-adjuvant systems (ClinicalTrials.gov, NCT04537208). Here, we further characterise the cellular immunogenicity profile of this vaccine candidate using a whole-blood secretion assay in parallel to intracellular cytokine staining (ICS) of cryopreserved peripheral blood mononuclear cells (PBMCs). Methods: A randomly allocated subset of 90 healthy, SARS-CoV-2-seronegative adults aged ≥ 18 years who had received (random allocation) one or two separate injections (on study day [D]1 and D22) of saline placebo or CoV2-PreS-dTM formulated with AS03 or AF03 were included. Cytokine secretion was assessed using a TruCulture® whole-blood stimulation system in combination with multiplex bead array, and intracellular cytokine profiles were evaluated on thawed PBMCs following ex vivo stimulation with recombinant S protein at pre-vaccination (D1), post-dose 1 (D22) and post-dose 2 (D36). Results: Both methods detected similar vaccine-induced responses after the first and second doses. We observed a Th1 bias (Th1/Th2 ratio > 1.0) for most treatment groups when analysed in whole blood, mainly characterised by increased IFN-γ, IL-2 and TNF-α secretion. Among participants aged ≥ 50 years, the Th1/Th2 ratio was higher for those who received vaccine candidate with AS03 versus AF03 adjuvant. ICS revealed that this higher Th1/Th2 ratio resulted from higher levels of IFN-γ expression and that the vaccine induced polyfunctional CD4+ T cells. Conclusions: The whole-blood cytokine secretion assay is a high-throughput alternative for assessing the quantity and character of vaccine-induced cellular responses.

3.
NPJ Vaccines ; 6(1): 158, 2021 Dec 21.
Article in English | MEDLINE | ID: covidwho-1585847

ABSTRACT

Emulsion adjuvants such as MF59 and AS03 have been used for more than two decades as key components of licensed vaccines, with over 100 million doses administered to diverse populations in more than 30 countries. Substantial clinical experience of effectiveness and a well-established safety profile, along with the ease of manufacturing have established emulsion adjuvants as one of the leading platforms for the development of pandemic vaccines. Emulsion adjuvants allow for antigen dose sparing, more rapid immune responses, and enhanced quality and quantity of adaptive immune responses. The mechanisms of enhancement of immune responses are well defined and typically characterized by the creation of an "immunocompetent environment" at the site of injection, followed by the induction of strong and long-lasting germinal center responses in the draining lymph nodes. As a result, emulsion adjuvants induce distinct immunological responses, with a mixed Th1/Th2 T cell response, long-lived plasma cells, an expanded repertoire of memory B cells, and high titers of cross-neutralizing polyfunctional antibodies against viral variants. Because of these various properties, emulsion adjuvants were included in pandemic influenza vaccines deployed during the 2009 H1N1 influenza pandemic, are still included in seasonal influenza vaccines, and are currently at the forefront of the development of vaccines against emerging SARS-CoV-2 pandemic variants. Here, we comprehensively review emulsion adjuvants, discuss their mechanism of action, and highlight their profile as a benchmark for the development of additional vaccine adjuvants and as a valuable tool to allow further investigations of the general principles of human immunity.

4.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-294807

ABSTRACT

The rapid spread of SARS-CoV-2 continues to impact humanity on a global scale with rising total morbidity and mortality. Despite the development of several effective vaccines, new products are needed to supply ongoing demand and the needs of specific populations. We report herein a pre-specified interim analysis of the phase 2 portion of an ongoing Phase 2/3, randomized, placebo-controlled trial of a coronavirus virus-like particle (CoVLP) vaccine candidate produced in plants that displays the SARS-CoV-2 spike glycoprotein adjuvanted with AS03 ( NCT04636697 ). A total of 753 subjects were recruited between 25 November 2020 and 24 March 2021 into three groups: Healthy Adults (18-64 years: N=306), Older Adults (≥ 65 years: N=282) and Adults with Comorbidities (≥18 years: N=165) and randomized 5:1 to receive two intramuscular doses of either vaccine CoVLP (3.75 μg/dose + AS03) or placebo 21 days apart. This report presents safety, tolerability and immunogenicity data collected up to 21 days after the second dose. The immune outcomes presented include neutralizing antibody (NAb) titres and cellular (IFN-γ and IL-4 ELISpot) responses. In this study, CoVLP+AS03 was well-tolerated and adverse events (AE) after each dose were generally mild to moderate and transient. Solicited AEs in Older Adults and Adults with Comorbidities were generally less frequent than in Healthy Adults. CoVLP+AS03 induced seroconversion in >35% of subjects in each group after the first dose and in ∼98% of subjects 21 days after the second dose. In all treatment groups, NAb levels were ∼10-fold higher than those in a panel of convalescent sera. A significant minority (∼20%) of subjects had evidence of a pre-existing IFN-γ response to the S protein and almost all subjects in all groups (>88%) had detectable cellular responses (IFN-γ, IL-4 or both) at 21 days after the second dose. A Th1-biased response was most evident after the first dose and was still present after dose two. These data demonstrated that CoVLP+AS03 will likely be well-tolerated and highly immunogenic in adults ≥18 years of age with and without comorbidities.

5.
Cell ; 184(21): 5432-5447.e16, 2021 10 14.
Article in English | MEDLINE | ID: covidwho-1454060

ABSTRACT

Understanding vaccine-elicited protection against SARS-CoV-2 variants and other sarbecoviruses is key for guiding public health policies. We show that a clinical stage multivalent SARS-CoV-2 spike receptor-binding domain nanoparticle (RBD-NP) vaccine protects mice from SARS-CoV-2 challenge after a single immunization, indicating a potential dose-sparing strategy. We benchmarked serum neutralizing activity elicited by RBD-NPs in non-human primates against a lead prefusion-stabilized SARS-CoV-2 spike (HexaPro) using a panel of circulating mutants. Polyclonal antibodies elicited by both vaccines are similarly resilient to many RBD residue substitutions tested, although mutations at and surrounding position 484 have negative consequences for neutralization. Mosaic and cocktail nanoparticle immunogens displaying multiple sarbecovirus RBDs elicit broad neutralizing activity in mice and protect mice against SARS-CoV challenge even in the absence of SARS-CoV RBD in the vaccine. This study provides proof of principle that multivalent sarbecovirus RBD-NPs induce heterotypic protection and motivates advancing such broadly protective sarbecovirus vaccines to the clinic.

6.
Cell ; 184(15): 3915-3935.e21, 2021 07 22.
Article in English | MEDLINE | ID: covidwho-1283262

ABSTRACT

Emerging evidence indicates a fundamental role for the epigenome in immunity. Here, we mapped the epigenomic and transcriptional landscape of immunity to influenza vaccination in humans at the single-cell level. Vaccination against seasonal influenza induced persistently diminished H3K27ac in monocytes and myeloid dendritic cells (mDCs), which was associated with impaired cytokine responses to Toll-like receptor stimulation. Single-cell ATAC-seq analysis revealed an epigenomically distinct subcluster of monocytes with reduced chromatin accessibility at AP-1-targeted loci after vaccination. Similar effects were observed in response to vaccination with the AS03-adjuvanted H5N1 pandemic influenza vaccine. However, this vaccine also stimulated persistently increased chromatin accessibility at interferon response factor (IRF) loci in monocytes and mDCs. This was associated with elevated expression of antiviral genes and heightened resistance to the unrelated Zika and Dengue viruses. These results demonstrate that vaccination stimulates persistent epigenomic remodeling of the innate immune system and reveal AS03's potential as an epigenetic adjuvant.


Subject(s)
Epigenomics , Immunity/genetics , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Single-Cell Analysis , Transcription, Genetic , Vaccination , Adolescent , Adult , Anti-Bacterial Agents/pharmacology , Antigens, CD34/metabolism , Antiviral Agents/pharmacology , Cellular Reprogramming , Chromatin/metabolism , Cytokines/biosynthesis , Drug Combinations , Female , Gene Expression Regulation , Histones/metabolism , Humans , Immunity, Innate/genetics , Influenza A Virus, H5N1 Subtype/drug effects , Influenza A Virus, H5N1 Subtype/immunology , Interferon Type I/metabolism , Male , Myeloid Cells/metabolism , Polysorbates/pharmacology , Squalene/pharmacology , Toll-Like Receptors/metabolism , Transcription Factor AP-1/metabolism , Transcriptome/genetics , Young Adult , alpha-Tocopherol/pharmacology
7.
Nature ; 594(7862): 253-258, 2021 06.
Article in English | MEDLINE | ID: covidwho-1192479

ABSTRACT

The development of a portfolio of COVID-19 vaccines to vaccinate the global population remains an urgent public health imperative1. Here we demonstrate the capacity of a subunit vaccine, comprising the SARS-CoV-2 spike protein receptor-binding domain displayed on an I53-50 protein nanoparticle scaffold (hereafter designated RBD-NP), to stimulate robust and durable neutralizing-antibody responses and protection against SARS-CoV-2 in rhesus macaques. We evaluated five adjuvants including Essai O/W 1849101, a squalene-in-water emulsion; AS03, an α-tocopherol-containing oil-in-water emulsion; AS37, a Toll-like receptor 7 (TLR7) agonist adsorbed to alum; CpG1018-alum, a TLR9 agonist formulated in alum; and alum. RBD-NP immunization with AS03, CpG1018-alum, AS37 or alum induced substantial neutralizing-antibody and CD4 T cell responses, and conferred protection against SARS-CoV-2 infection in the pharynges, nares and bronchoalveolar lavage. The neutralizing-antibody response to live virus was maintained up to 180 days after vaccination with RBD-NP in AS03 (RBD-NP-AS03), and correlated with protection from infection. RBD-NP immunization cross-neutralized the B.1.1.7 SARS-CoV-2 variant efficiently but showed a reduced response against the B.1.351 variant. RBD-NP-AS03 produced a 4.5-fold reduction in neutralization of B.1.351 whereas the group immunized with RBD-NP-AS37 produced a 16-fold reduction in neutralization of B.1.351, suggesting differences in the breadth of the neutralizing-antibody response induced by these adjuvants. Furthermore, RBD-NP-AS03 was as immunogenic as a prefusion-stabilized spike immunogen (HexaPro) with AS03 adjuvant. These data highlight the efficacy of the adjuvanted RBD-NP vaccine in promoting protective immunity against SARS-CoV-2 and have led to phase I/II clinical trials of this vaccine (NCT04742738 and NCT04750343).


Subject(s)
Adjuvants, Immunologic , Antibodies, Neutralizing/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Vaccines, Subunit/immunology , Alum Compounds , Animals , Antibodies, Viral/immunology , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/immunology , COVID-19/virology , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Disease Models, Animal , Immunity, Cellular , Immunity, Humoral , Macaca mulatta/immunology , Male , Oligodeoxyribonucleotides , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Squalene
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