Rivax, Vaccine Against Bioterrorism Weapon Ricin, Passes Phase 1 Clinical Studies

Filed in archive Drugs, Vaccines and Therapeutics on February 5, 2006

This entry is submitted by Gloria Gamat, via Creative Reporter.Ricin is a potentially deadly toxin extracted from castor beans which could be used as a bioterrorism weapon. It can be administered in food and water or sprayed as an aerosol, and (depending on delivery) can cause fever, nausea and abdominal pain or lung disease before causing death.

There is no antidote after the first few hours of exposure and, because symptoms do not appear until later and often mimic other illnesses, individuals often do not know if they have been exposed until it is too late for treatment.

The poison was used during the Cold War to kill Bulgarian dissident Georgi Markov in London. An especially-equipped umbrella was used to inject a pellet coated with 450 micrograms of ricin into his leg in an infamous attack on Waterloo Bridge in 1978. Last year an Algerian, Kamel Bourgass, was convicted of plotting to use poisons - including ricin - to cause disruption, fear or injury.

The vaccine against Ricin, called RiVax which includes a genetically modified subunit of the toxin has been found safe, according to researchers from the University of Texas Southwestern Medical Center who worked on the Phase I safety and immunogenicity dose-escalation study:

Study participants only reported mild side effects, the researchers said - such as a sore arm at the site of injections or mild headache, which might be seen with any jab.

Based on the protection they observed in the mice, the researchers projected that a human given the vaccine could withstand a lethal dose of injected ricin - estimated to be as little as approximately 500 micrograms, an amount that would fit on the head of a pin.

Sources: Ivanhoe.com, BBC NewsAbout Gloria Gamat: Gloria is a proud single-mom to Raine (Rainier Brando: born 29 December 2002) and a Chemist. Gloria also blogs about motherhood at EMothersOnline and about life and travel in the Philippines at The Philippine Culture Blog and at Pinoy Travel Blog respectively.