Days After Ricin Mailings, Pentagon Says it Wants a Vaccine

The United States needs a vaccine to protect troops against ricin, the Defense Department said in an announcement issued days after envelopes filled with the deadly toxin were mailed to President Obama and two Mississippi public officials.

No antidote or means of prevention yet exists for ricin, which can be lethal in minute quantities in the bloodstream. A judge on Monday ordered 41-year-old Mississippi resident Everett Dutschke to be held without bond until a Thursday hearing for allegedly sending the poisonous substance to the White House, the Washington office of Sen. Roger Wicker, R-Miss., and a judge in Mississippi. The mailed material ultimately harmed none of its handlers or intended recipients.

The Pentagon "has a new requirement for a pre-exposure prophylaxis ricin vaccine that provides balanced onset and duration of protection for administration to healthy individuals," says the "request for information" published on April 22.  The document sets a May 10 deadline for organizations to present developmental vaccines for consideration. The aim is to prepare a treatment to test in animals and ultimately to secure Food and Drug Administration licensing of a vaccine.

"Presumably if several companies smell funding possibilities in the future, they will volunteer information that they have developed [a drug] that might be a good vaccine," said Graham Peaslee, a chemistry and environmental science professor at Hope College in Holland, Mich. "Then DoD would come back with a [request] to test them."

Last week's request came from a procurement program involved in providing anthrax and smallpox vaccinations to military personnel, but the document does not specify which service members could receive a ricin treatment if one is produced. Mississippi National Guard forces reportedly took part in raids last week of Dutschke's residence and former martial arts school; a court affidavit says investigators found ricin on a dust mask and other items found near the school, theAssociated Press reported.

One experimental vaccine against the toxin generated human immune responses in a trial launched in 2011 at the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick, Md., according to Nature. Additional tests are necessary, though, and the project now faces uncertain funding prospects, the journal reported.

The rationale behind the Pentagon's latest request was unclear, as were the development project's anticipated time line and cost. A spokesman did not respond by press time to a request for comment.

Peaslee, though, suggested the Defense Department is "looking for a backup plan in case the Army-developed vaccine doesn't work."

"They may have more info that hasn't been released on the Army trials, or they may just have a real sense of urgency" due to the recent ricin incident, he said by e-mail.

Ricin countermeasures have also been a focus of several university-backed studies. Australianscientists in 2011 suggested an eventual antidote could act by inhibiting a victim's production of a specific protein, and British researchers last year said black tea's antioxidants might help to counter the toxin's harmful effects.

Plots involving the toxin have generally been limited to individuals and small groups, with the possible exception of Bulgarian dissident Georgi Markov's death by ricin-tipped umbrella stabbing in 1978.