Inovio Biomedical Corporation (NYSE Amex:INO), a leader in DNA vaccine design, development and delivery, announced today that data generated from a pre-clinical collaborative study by National Cancer Institute (NCI) and Inovio scientists were published in the scientific journal Proceedings of the National Academy of Sciences in a paper entitled: “DNA vaccination in rhesus macaques induces potent immune responses and decreases acute and chronic viremia after SIVmac251 challenge.” The senior author of this study is Dr. George Pavlakis, Senior Investigator & Chief, Human Retrovirus Section Vaccine Branch, NCI.
The primary aim of this study was to assess protective capabilities of optimized DNA vaccines delivered using Inovio’s proprietary electroporation system against simian immunodeficiency virus (SIV), which is closely related to human immunodeficiency virus (HIV). Animals receiving an NCI vaccine were challenged 14 weeks after a four-dose vaccination regime with a highly pathogenic strain of SIV and followed for 32 weeks post-challenge. Vaccinated animals exhibited greatly reduced viremia (the spread of a virus via the bloodstream) during acute and chronic phases of infection compared to control animals, indicative of better control of infection.
Vaccinated animals developed strong cellular and humoral responses against the DNA vaccine antigens. Vaccination induced strong memory responses that were maintained at the day of challenge. Development of high levels of effector memory T cells suggested the potential for rapid immune system mobilization upon SIV challenge. These results demonstrate that DNA vaccines delivered using only electroporation, without a heterologous boost with, for example, an alternative vaccine modality such as a viral vector-based vaccine, can provide acute and chronic protection from high viremia that is comparable to other vaccine modalities that have been previously tested in this macaque model.