Extracted from castor oil beans, ricin is one of the weapons that could be used in a bio-terror attack. It acts by damaging the organs; a combination of pulmonary, liver and renal failure can lead to death.
It can be mixed in food and water, or sprayed as an aerosol.
As symptoms are not evident until later and often resemble those of other illnesses, individuals often do not know if they have been exposed until it is too late for treatment.
Published in Proceedings of the National Academy of Sciences, U.S. research suggests the vaccine produced no significant side effects.
Scientists must now figure out the ideal dosage and formulation of the vaccine before continuing with their study.
