Seattle scientist works to develop new leprosy vaccine

Leprosy research isn't what it used to be.

For the most part, that's a good thing; it means people are getting better. Since the 1980s, when the World Health Organization (WHO) began dispensing free drugs to countries reporting leprosy, the number of cases worldwide has sunk dramatically.

So it only makes sense that the funding for an improved vaccine has dipped, too.

But in a lab on Capitol Hill, Malcolm Duthie is trying to trim those numbers even more. Duthie heads the Infectious Disease Research Institute's (IDRI) leprosy vaccine-development program, where a vaccine has been in the works since the early 2000s with the help of a grant from American Leprosy Missions.

Leprosy, Duthie said, " ... is viewed as a disease that is dying and will be eradicated."

IDRI aims to have the new vaccine ready for safety trials by the beginning of 2011. The institute is also developing more rapid diagnostic tools — ideally, a blood test that can diagnose leprosy in 10 minutes.

"That takes a lot of pressure off a clinician looking at symptoms saying, 'Hmm, you could have leprosy, you could have a fungal infection, you could have this other thing,'" Duthie said. "It gives them something so that during your visit to the doctor, you can get a definitive answer."

That may be the only thing that's definitive about this disease. Even the WHO statistics aren't fully reliable.

Part of the problem is that there's no way of knowing how many leprosy cases don't get reported.

When clinicians survey leprosy-ridden villages and towns themselves, they often find six or seven times more cases than reported, Duthie said.

There's also a fairly high rate of misdiagnosis. "The primary way leprosy presents itself is as lesions," Duthie said. "It can look like an awful lot of other diseases. [Patients] just basically get treated for the wrong thing."

It's not uncommon for doctors to treat the disease as a fungal infection, only realizing that there could be a deeper problem when the patient doesn't recover.

Duthie hopes that the new vaccine will help to prevent the disease from showing up in the first place.

"Our belief is that a vaccine will give an active protection," Duthie said. "If we can vaccinate people, we could potentially break the transmission cycle."