The outer membrane protein F gene (oprF) of Pseudomonas aeruginosa was recently shown by us to protect mice from P. aeruginosa chronic pulmonary infection when used as a DNA vaccine administered by three biolistic (gene gun) intradermal inoculations given at 2-week intervals. In the present study, we used two different strategies to improve the protective efficacy of the DNA vaccine. In the fir...

A combination of different types of vaccines usually induces enhanced immune responses in comparison to immunization with single vaccines. The highest efficacy of a heterologous prime-boost strategy is mostly achieved after priming with a DNA vaccine and boosting with a recombinant virus or a protein vaccine. The aim of this study was to determine whether the combination of a DNA and cellular v...

BACKGROUND West Nile virus (WNV) is a flavivirus that causes meningitis and encephalitis. There are no licensed vaccines to prevent WNV in humans. The safety and immunogenicity of a first-generation WNV DNA vaccine was demonstrated in a clinical trial and a similar DNA vaccine has been licensed for use in horses. METHODS A DNA vaccine encoding the protein premembrane and the E glycoproteins o...

Priming immunization plays a key role in protecting individuals or populations to influenza viruses that are novel to humans. To identify the most promising vaccine priming strategy, we have evaluated different prime-boost regimens using inactivated, DNA and live attenuated vaccines in ferrets. Live attenuated influenza A/Vietnam/1203/2004 (H5N1) candidate vaccine (LAIV, VN04 ca) primed ferrets...

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus capable of causing a severe hemorrhagic fever disease in humans. There are currently no licensed vaccines to prevent CCHFV-associated disease. We developed a DNA vaccine expressing the M-segment glycoprotein precursor gene of CCHFV and assessed its immunogenicity and protective efficacy in two lethal mouse models of disease: ty...

Plasmid DNA vaccines capable of preventing viral, bacterial, and parasitic infections are currently under development. Our labs have shown that a plasmid DNA vaccine encoding the circumsporozoite protein of the malaria parasite elicits protective immunity against live sporozoite challenge in adult BALB/c mice. We now find that the same DNA vaccine induces tolerance rather than immunity when adm...

The immunogenicity and durability of genetic vaccines are influenced by the composition of gene inserts and choice of delivery vector. DNA vectors are a promising vaccine approach showing efficacy when combined in prime-boost regimens with recombinant protein or viral vectors, but they have shown limited comparative efficacy as a stand-alone platform in primates, due possibly to suboptimal gene...

Arginine-specific cysteine proteinases (RgpA and RgpB) produced by the periodontal pathogen Porphyromonas gingivalis are suspected virulence factors and are involved in interrupting host defense mechanisms as well as in penetrating and destroying periodontal connective tissues. To induce a protective immune response against P. gingivalis, we constructed an rgpA DNA vaccine. BALB/c mice were imm...

IL-12 has been shown to enhance cellular immunity in vitro and in vivo. Recent reports have suggested that combining DNA vaccine approach with immune stimulatory molecules delivered as genes may significantly enhance Ag-specific immune responses in vivo. In particular, IL-12 molecules could constitute an important addition to a herpes vaccine by amplifying specific immune responses. Here we inv...

DNA vaccines against cancer have shown promising results in animal models. Efficient antigen-specific T cell responses and tumor protection have been demonstrated after vaccination with DNA encoding tumor antigens in mice. Phase I clinical trials have furthermore demonstrated that repetitive DNA vaccinations in humans are well tolerated, and that tumor antigen-specific immune responses can be i...