Topical vaccine protects against inhaled ricin


BALTIMORE, MD March 8, 2004 -- An experimental vaccine that can be applied directly to the skin or via a patch protects mice from lethal exposure to aerosolized ricin. Researchers present their findings today at the American Society for Microbiology's (ASM) Biodefense Research Meeting.

"No vaccine or specific therapy is currently available for ricin poisoning," says Gary Matyas of the Walter Reed Army Institute of Research, a presenter on the study which also included scientists from the United States Army Research Medical Institute of Infectious Diseases and Iomai Corporation.

In the study, the researchers incorporated a harmless fragment of the ricin molecule (RTA 1-33/44-198) into a transcutaneous immunization (TCI) formulation. TCI is a needle-free alternative for vaccination in which the antigen is mixed with adjuvant and applied directly to the skin or on a patch that is applied to the skin. The vaccine was then applied either directly to the skin of mice or incorporated into a patch. After several weeks all the mice showed high levels of anti-ricin immune responses. All the mice that had received the direct application survived a lethal challenge of inhaled ricin and 70% of those that received the vaccine via the patch survived.

"Transcutaneous immunization with RTA 1-33/44-198 offers a viable alternative delivery route for this promising recombinant ricin vaccine candidate," says Matyas.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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