Influenza hemagglutinin (HA) is considered a major protective antigen of seasonal influenza vaccine but antigenic drift of HA necessitates annual immunizations using new circulating HA versions. Low variation found within conserved non-HA influenza virus (INFV) antigens may maintain protection with less frequent immunizations. Conserved antigens of influenza A virus (INFV A) that can generate cross protection against multiple INFV strains were evaluated in BALB/c mice using modified Vaccinia virus Ankara (MVA)-vectored vaccines that expressed INFV A antigens hemagglutinin (HA), matrix protein 1 (M1), nucleoprotein (NP), matrix protein 2 (M2), repeats of the external portion of M2 (M2e) or as tandem repeats (METR), and M2e with transmembrane region and cytoplasmic loop (M2eTML).
View Article and Find Full Text PDFBackground: The rapid evolution of new sublineages of H5N1 influenza poses the greatest challenge in control of H5N1 infection by currently existing vaccines. To overcome this, an MVAtor vector expressing three H5HA antigens A/Vietnam/1203/04, A/Indonesia/669/06 and A/Anhui/01/05 (MVAtor-tri-HA vector) was developed to elicit broad cross-protection against diverse clades by covering amino acid variations in the major neutralizing epitopes of HA among H5N1 subtypes.
Methods: BALB/c mice and guinea pigs were immunized i.
Antimicrob Agents Chemother
November 2013
Bacillus anthracis toxins can be neutralized by antibodies against protective antigen (PA), a component of anthrax toxins. Anthrivig (human anthrax immunoglobulin), also known as AIGIV, derived from plasma of humans immunized with BioThrax (anthrax vaccine adsorbed), is under development for the treatment of toxemia following exposure to anthrax spores. The pharmacokinetics (PK) of AIGIV was assessed in naive animals and healthy human volunteers, and the efficacy of AIGIV was assessed in animals exposed via inhalation to aerosolized B.
View Article and Find Full Text PDFThe global spread of highly pathogenic avian influenza virus (H5N1 subtype) has promoted efforts to develop human vaccines against potential pandemic outbreaks. However, current platforms for influenza vaccine production are cumbersome, limited in scalability and often require the handling of live infectious virus. We describe the production of hemagglutinin from the A/Indonesia/05/05 strain of H5N1 influenza virus by transient expression in plants, and demonstrate the immunogenicity and protective efficacy of the vaccine candidate in animal models.
View Article and Find Full Text PDFIn this study, recombinant virus-like particles (VLPs) were evaluated as a candidate vaccine against emerging influenza viruses with pandemic potential. The VLPs are composed of the hemagglutinin (HA), neuraminidase (NA), and matrix 1 (M1) proteins of the H5N1 A/Indonesia/05/2005 (clade 2.1; [Indo/05]) virus, which were expressed using baculovirus in Spodoptera frugiperda (Sf9) cells.
View Article and Find Full Text PDFHow viral and host factors contribute to the severe pathogenicity of the H5N1 subtype of avian influenza virus infection in humans is poorly understood. We identified three clusters of differentially expressed innate immune response genes in lungs from H5N1 (A/Vietnam/1203/04) influenza virus-infected ferrets by oligonucleotide microarray analysis. Interferon response genes were more strongly expressed in H5N1-infected ferret lungs than in lungs from ferrets infected with the less pathogenic H3N2 subtype.
View Article and Find Full Text PDFThere are legitimate concerns that the highly pathogenic H5N1 avian influenza virus could adapt for human-to-human transmission and cause a pandemic similar to the 1918 "Spanish flu" that killed 50 million people worldwide. We have developed pandemic influenza vaccines by incorporating multiple antigens from both avian and Spanish influenza viruses into complex recombinant adenovirus vectors. In vaccinated mice, these vaccines induced strong humoral and cellular immune responses against pandemic influenza virus antigens, and protected vaccinated mice against lethal H5N1 virus challenge.
View Article and Find Full Text PDFA dose-response model using rhesus monkeys as a surrogate for pregnant women indicates that oral exposure to 10(7) CFU of Listeria monocytogenes results in about 50% stillbirths. Ten of 33 pregnant rhesus monkeys exposed orally to a single dose of 10(2) to 10(10) CFU of L. monocytogenes had stillbirths.
View Article and Find Full Text PDFInfluenza virus is a highly infectious respiratory pathogen that results in severe morbidity and mortality. The current licensed trivalent vaccine formulations in the U.S.
View Article and Find Full Text PDFListeriosis results from exposure to the foodborne pathogen Listeria monocytogenes. Although many different strains of L. monocytogenes are isolated from food, no definitive tests currently predict which isolates are most virulent.
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