Positive intradermal testing results announced for Rivax

Soligenix, Inc., has announced positive results for intradermal injection testing of Rivax, its vaccine against mucosal and systemic ricin intoxication.

The study, to be published in the June 2010 edition of Vaccine, sought to determine whether intradermal injection would be effective at lower doses in comparison to intramuscular injection, with or without an aluminum salt adjuvant. In the study, mice were tested with systemic, gastric gavage or aerosol challenges.

When used with an aluminum adjuvant, the vaccine offered significantly better protection for the animals tested through intradermal administration  against ricin toxin than those tested by the intramuscular route. This result means that a lower dose could potentially be used. Without the aluminum adjuvant both routes were equally protective.

“ID vaccination was highly effective at protecting the lungs of mice from ricin aerosols, a likely route of delivery in the setting of bioterrorism,” Dr. Ellen Vitetta, director of the Cancer Immunobiology Center at UT Southwestern and the study’s senior author, said.

Intradermal injection holds several practical advantages over intramuscular injection due to the ease with which it can be administered. It also eliminates the use of needles, an important consideration for its potential use in an emergency situation.

RiVax is now in Phase 1 human safety and immunogenicity trials and efficacy trials for non-human primates.