TECHNOLOGY & PRODUCTS

Vaccine Evolution

The GeoVax DNA & MVA product selected for further development and human testing is based on more than 15 years of development studies, during which time less effective vaccines were evaluated and eliminated from consideration. The aforementioned studies led to the rationale for developing the Gag-Pol-Env multiprotein expressing gene cassettes present in our product DNA & MVA vaccines. The vaccines have proven effective by:

• Using single DNA and MVA vectors to express the three major proteins of immunodeficiency viruses (Gag, Pol, and Env)
• Use of MVA instead of fowlpox for the booster vaccine because MVA stimulated better immune responses than fowlpox in preclinical trials.
• Utilizing only three vaccinations: DNA at 0 and 8 weeks, poxvirus (MVA) at 24 weeks.
• Demonstrating long-term memory responses were protective by waiting for 7 months before administering an intra-rectal challenge. At the time of challenge, the vaccine response was in memory but successfully activated to provide protection when stimulated by the presence of the AIDS virus.

Results Summary

• Excellent protection in vaccinated monkeys against a mucosal immunodeficiency virus challenge by both high and low dose intradermal DNA priming (12/12 monkeys) .
• Excellent protection against mucosal challenge by high dose intramuscular DNA priming (6/6 monkeys).
  • Excellent protection of vaccinated monkeys receiving low dose intramuscular DNA priming (5/6 monkeys).
  • The 1/6 not protected only received a partial dose.
• Protection of vaccinated monkeys held more than 40 months post challenge. Vaccination controlled residual virus in blood stream to the low levels characteristic of long-term non-progressors.Vaccine prevented clinical signs of AIDS.