Article

The relative immunogenicity of DNA vaccines delivered by the intramuscular needle injection, electroporation and gene gun methods

China-US Vaccine Research Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
Vaccine (Impact Factor: 3.62). 05/2008; 26(17):2100-10. DOI: 10.1016/j.vaccine.2008.02.033
Source: PubMed

ABSTRACT

Immunogenicity of DNA vaccines varies significantly due to many factors including the inherent immunogenicity of the protein antigen encoded in the DNA vaccine, the optimal immune responses that can be achieved in different animal models and in humans with different genetic backgrounds and, to a great degree, the delivery methods used to administer the DNA vaccines. Based on published results, only the gene gun-mediated delivery approach has been able to elicit protective levels of immune responses in healthy, adult volunteers by DNA immunization alone without the use of another vaccine modality as a boost. Recent results from animal studies suggest that electroporation is also effective in eliciting high level immune responses. However, there have been no reports to identify the similarities and differences between these two leading physical delivery methods for DNA vaccines against infectious disease targets. In the current study, we compared the relative immunogenicity of a DNA vaccine expressing a hemagglutinin (HA) antigen from an H5N1 influenza virus in two animal models (rabbit and mouse) when delivered by either intramuscular needle immunization (IM), gene gun (GG) or electroporation (EP). HA-specific antibody, T cell and B cell responses were analyzed. Our results indicate that, overall, both the GG and EP methods are more immunogenic than the IM method. However, EP and IM stimulated a Th-1 type antibody response and the antibody response to GG was Th-2 dominated. These findings provide important information for the further selection and optimization of DNA vaccine delivery methods for human applications.

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    • "Furthermore, molecular adjuvant was still included in the above DNA vaccine formulation despite the use of EP delivery, making the whole formulation/delivery package very complicated and potentially expensive. The relative immunogenicity of traditional needle injection, gene gun, and electroporation was compared in a mouse model using HA antigen of avian influenza subtype H5N1 [63]. Both gene gun and electroporation methods were found more immunogenic than traditional needle injection. "
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