Topic
Anthrax vaccines
About: Anthrax vaccines is a research topic. Over the lifetime, 685 publications have been published within this topic receiving 21495 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: The current available human vaccines are far from ideal, they are expensive to produce, require repeated doses and may invoke transient side‐effects in some individuals and there is also evidence to suggest that they may not give full protection against all strains of B. anthracis.
Abstract: Bacillus anthracis is the causative organism of the disease anthrax. The ability of the organism to form resistant spores and infect via the aerosol route has led to it being considered as a potential biological warfare agent. The current available human vaccines are far from ideal, they are expensive to produce, require repeated doses and may invoke transient side-effects in some individuals. There is also evidence to suggest that they may not give full protection against all strains of B. anthracis.
A new generation of anthrax vaccine is therefore needed. The use of Lactobacillus as a vector for expression of heterologous proteins from pathogens supplies us with a safe system, which can be given orally. Lactobacilli are commensals of the gut, generally regarded as safe and have intrinsic adjuvanticity. Oral vaccines may stimulate the mucosol immune system to produce local IgA responses in addition to systemic responses. These vectors are delivered at the mucosal surface, the site where the infection actually occurs and where the first line of defence lies.
The gene encoding the protective antigen (PA) of B. anthracis, an immunogenic non-toxic component of the two toxins produced, is being cloned into different homologous vectors and subsequently transformed to various Lactobacillus strains. High intracellular expression levels for the PA in Lact. casei were achieved. Mucosal antigen presentation and humoral and cellular immune responses following immunization with transformants expressing PA in various ways (intracellular, surface-anchored and extracellular) are being studied.
91 citations
TL;DR: The possibility of the development of a single-dose and adjuvant-free protective antigen based anthrax vaccine in the form of PAD4-NP is demonstrated for the first time.
Abstract: Bacillus anthracis, the etiological agent of anthrax, is a major bioterror agent. Vaccination is the most effective prophylactic measure available against anthrax. Currently available anthrax vaccines have issues of the multiple booster dose requirement, adjuvant-associated side effects and stability. Use of biocompatible and biodegradable nanoparticles to deliver the antigens to immune cells could solve the issues associated with anthrax vaccines. We hypothesized that the delivery of a stable immunogenic domain 4 of protective antigen (PAD4) of Bacillus anthracis encapsulated in a poly (lactide-co-glycolide) (PLGA) - an FDA approved biocompatible and biodegradable material, may alleviate the problems of booster dose, adjuvant toxicity and stability associated with anthrax vaccines. We made a PLGA based protective antigen domain 4 nanoparticle (PAD4-NP) formulation using water/oil/water solvent evaporation method. Nanoparticles were characterized for antigen content, morphology, size, polydispersity and zeta potential. The immune correlates and protective efficacy of the nanoparticle formulation was evaluated in Swiss Webster outbred mice. Mice were immunized with single dose of PAD4-NP or recombinant PAD4. The PAD4-NP elicited a robust IgG response with mixed IgG1 and IgG2a subtypes, whereas the control PAD4 immunized mice elicited low IgG response with predominant IgG1 subtype. The PAD4-NP generated mixed Th1/Th2 response, whereas PAD4 elicited predominantly Th2 response. When we compared the efficacy of this single-dose vaccine nanoformulation PAD4-NP with that of the recombinant PAD4 in providing protective immunity against a lethal challenge with Bacillus anthracis spores, the median survival of PAD4-NP immunized mice was 6 days as compared to 1 day for PAD4 immunized mice (p<0.001). Thus, we demonstrate, for the first time, the possibility of the development of a single-dose and adjuvant-free protective antigen based anthrax vaccine in the form of PAD4-NP. Further work in this direction may produce a better and safer candidate anthrax vaccine.
91 citations
TL;DR: This in vitro assay measures the functional ability of antisera, containing antibodies to anthrax lethal toxin, to specifically protect J774A.1 cells against Bacillus anthracis lethal toxin cytotoxicity.
88 citations
TL;DR: The efficacy of an anthrax vaccine licensed for human use, MDPH-PA, was tested in guinea-pigs intramuscularly challenged with 10, 100 or 1000 LD50 of spores from two virulent strains of Bacillus anthracis, Vollum 1B and Ames.
88 citations
TL;DR: It is suggested that the use of S. typhimurium to deliver PA is an effective approach for inducing protection against B. anthracis and that the degree of protection demonstrated in the mouse may not fully indicate the potential of the recombinant Salmonella as an effective vaccine in other species.
87 citations