Li Sheng-Fowler

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The presence of some residual cellular DNA derived from the production-cell substrate in viral vaccines is inevitable. Whether this DNA represents a safety concern, particularly if the cell substrate is derived from a tumor or is tumorigenic, is unknown. DNA has two biological activities that need to be considered. First, DNA can be oncogenic; second, DNA(More)
Vaccines contain residual DNA derived from the cells used to produce them. As part of our investigation to assess the risk of this cellular DNA, we are developing a quantitative in vivo assay to assess the oncogenicity of DNA. In an earlier study, we had generated expression plasmids for two oncogenes--human activated T24-H-ras and murine c-myc--and had(More)
As part of safety studies to evaluate the risk of residual cellular DNA in vaccines manufactured in tumorigenic cells, we have been developing in vivo assays to detect and quantify the oncogenic activity of DNA. We generated a plasmid expressing both an activated human H-ras gene and murine c-myc gene and showed that 1 µg of this plasmid,(More)
Development of vaccines against highly pathogenic viruses that could also be used as agents of bioterrorism is both a public health issue and a national security priority. Methods that can quantify neutralizing antibodies will likely be crucial in demonstrating vaccine effectiveness, as most licensed viral vaccines are effective due to their capacity to(More)
All viral vaccines contain contaminating residual DNA derived from the production cell substrate. The potential risk of this DNA, particularly when derived from tumorigenic cells, has been debated for over 40 years. While the major risk has been considered to be the oncogenicity of the DNA, another potential risk is that a genome of an infectious virus is(More)
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