Background: A candidate pandemic influenza H5N1 vaccine should provide rapid and long-lasting immunity against antigenically drifted viruses. As H5N1 viruses are poorly immunogenic, this may require a combination of immune potentiating strategies. An attractive approach is combining the intrinsic immunogenicity of virosomes with another promising adjuvant to further boost the immune response. As regulatory authorities have not yet approved a surrogate correlate of protection for H5N1 vaccines, it is important to test the protective efficacy of candidate H5N1 vaccines in a viral challenge study.
Objectives: This study investigated in a murine model the protective efficacy of Matrix-M adjuvanted virosomal influenza H5N1 vaccine against highly pathogenic lethal viral challenge.
Methods: Mice were vaccinated intranasally (IN) or intramuscularly (IM) with 7·5 μg and 30 μg HA of inactivated A/Vietnam/1194/2004 (H5N1) (NIBRG-14) virosomal adjuvanted vaccine formulated with or without 10 μg of Matrix-M adjuvant and challenged IN with the highly pathogenic A/Vietnam/1194/2004 (H5N1) virus.
Results And Conclusions: IM vaccination provided protection irrespective of dose and the presence of Matrix-M adjuvant, whilst the IN vaccine required adjuvant to protect against the challenge. The Matrix-M adjuvanted vaccine induced a strong and cross-reactive serum antibody response indicative of seroprotection after both IM and IN administration. In addition, the IM vaccine induced the highest frequencies of influenza specific CD4+ and CD8+ T-cells. The results confirm a high potential of Matrix-M adjuvanted virosomal vaccines and support the progress of this vaccine into a phase 1 clinical trial.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5780659 | PMC |
| http://dx.doi.org/10.1111/j.1750-2659.2011.00256.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Safety and efficacy of the blood-stage malaria vaccine RH5.1/Matrix-M in Burkina Faso: interim results of a double-blind, randomised, controlled, phase 2b trial in children.
Lancet Infect Dis
December 2024
Department of Biochemistry and Kavli Institute for Nanoscience Discovery and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK. Electronic address:
Background: Two pre-erythrocytic vaccines (R21/Matrix-M and RTS,S/AS01) are now approved for Plasmodium falciparum malaria. However, neither induces blood-stage immunity against parasites that break through from the liver. RH5.
View Article and Find Full Text PDFImmunogenicity and safety following a homologous booster dose of a SARS-CoV-2 recombinant spike protein vaccine with Matrix-M adjuvant (NVX-CoV2373) versus a primary series in people living with and without HIV-1 infection in South Africa: A randomized crossover phase 2a/2b trial.
Hum Vaccin Immunother
December 2024
South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
COVID-19 remains a global public health issue and an improved understanding of vaccine performance in immunocompromised individuals, including people living with HIV (PLWH), is needed. Initial data from the present study's pre-crossover/booster phase were previously reported. This phase 2a/b clinical trial in South Africa (2019nCoV-501/NCT04533399) revisits 1:1 randomly assigned HIV-negative adults (18-84 years) and medically stable PLWH (18-64 years) who previously received two NVX-CoV2373 doses (5 μg recombinant Spike protein with 50 μg Matrix-M™ adjuvant) or placebo.
View Article and Find Full Text PDFProC6C, a novel multi-stage malaria vaccine, elicits functional antibodies against the minor and central repeats of the Circumsporozoite Protein in human adults.
Front Immunol
November 2024
Department for Congenital Disorders, Statens Serum Institut (SSI), Copenhagen, Denmark.
Introduction: ProC6C is a multi-stage malaria vaccine which includes Circumsporozoite Protein (PfCSP), Pfs48/45 and Pfs230 sequences, designed to elicit functional antibodies that prevent sporozoite invasion of human hepatocytes (PfCSP) and parasite development in mosquitoes (Pfs48/45 and Pfs230). ProC6C formulated on Alhydrogel was evaluated in combination with Matrix-M in a Phase 1 trial in Burkina Faso. The PfCSP antibody responses were assessed for magnitude, specificity, avidity and functionality.
View Article and Find Full Text PDFA comparative immunological assessment of multiple clinical-stage adjuvants for the R21 malaria vaccine in nonhuman primates.
Sci Transl Med
July 2024
Institute for Immunity, Transplantation and Infection, School of Medicine, Stanford University, Stanford, CA 94305, USA.
Authorization of the Matrix-M (MM)-adjuvanted R21 vaccine by three countries and its subsequent endorsement by the World Health Organization for malaria prevention in children are a milestone in the fight against malaria. Yet, our understanding of the innate and adaptive immune responses elicited by this vaccine remains limited. Here, we compared three clinically relevant adjuvants [3M-052 + aluminum hydroxide (Alum) (3M), a TLR7/8 agonist formulated in Alum; GLA-LSQ, a TLR4 agonist formulated in liposomes with QS-21; and MM, the now-approved adjuvant for R21] for their capacity to induce durable immune responses to R21 in macaques.
View Article and Find Full Text PDFPreclinical development of a stabilized RH5 virus-like particle vaccine that induces improved antimalarial antibodies.
Cell Rep Med
July 2024
Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, OX1 3QU Oxford, UK; Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, OX1 3QU Oxford, UK; The Jenner Institute, University of Oxford, Old Road Campus Research Building, OX3 7DQ Oxford, UK; NIHR Oxford Biomedical Research Centre, Oxford, UK. Electronic address:
Plasmodium falciparum reticulocyte-binding protein homolog 5 (RH5) is a leading blood-stage malaria vaccine antigen target, currently in a phase 2b clinical trial as a full-length soluble protein/adjuvant vaccine candidate called RH5.1/Matrix-M. We identify that disordered regions of the full-length RH5 molecule induce non-growth inhibitory antibodies in human vaccinees and that a re-engineered and stabilized immunogen (including just the alpha-helical core of RH5) induces a qualitatively superior growth inhibitory antibody response in rats vaccinated with this protein formulated in Matrix-M adjuvant.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!