Dengue and Zika viruses are mosquito-borne flaviviruses related to Japanese encephalitis and yellow fever viruses. Estimates indicate ~400 million of dengue infections per year, of which ~100 million show clinical signs. Approximately 3.9 billion people in 128 countries are at risk of infection. There are 4 distinct serotypes of the virus. Recovery from infection by one provides lifelong immunity against that particular serotype. However, subsequent infections by other serotypes increase the risk of developing severe dengue hemorrhagic fever.
Several experimental vaccines are in the development. Medigen uses iDNA technology encoding the synthetic, live-attenuated dengue vaccines for all four serotypes, as well as for related Zika vaccine.
Dengue and Zika iDNA plasmids can be used either directly for vaccination, or for preparation of safer live-attenuated vaccine in cell culture.
The advantages of Medigen’s iDNA technology include natural immunity and a higher level of safety, the latter resulting from the genetic stability of iDNA. In addition, cold chain may not be needed, as iDNA can be formulated for ambient temperature.