A Vaccine for Leprosy

Leprosy Vaccine in the United States

Logo for the American Leprosy Missions, an organization dedicated to leprosy research and eradication.

In the United States, these is no official, nationally accepted “vaccine” for leprosy. For over 15 years, researchers have been doing complementary analysis of tuberculosis vaccines, such as the BCG (Bacillus Calmette Guerin) vaccine, to see if they have an effect on the closely related Mycobacterium leprae. Throughout the process of attempting to sequence the M.leprae genome and bioinformatic processing of the data, researchers have changed the way the U.S. investigates potential antigens for new vaccines. The debate still continues, however, as to whether there is a need for a vaccine in the overall strategy to control and/or eradicate leprosy on a national and international scale.

The BCG vaccine is not used in the United States as a leprosy vaccine because of the unproven effectiveness of the BCG vaccine as well as the low incidence of leprosy patients in America. According to Dr. Barbara Stryjdwska, Clinician at the National Hansen’s Disesase Programs in Louisiana, there are only approximately 150 new leprosy cases each year in the United States, and most of these are in immigrants coming from countries where Hansen’s Disease is endemic. In 2002, 96 cases were reported to the Center for Disease Control and Prevention. The incidence may be greater however, because many patients do not want to be reported because of their immigrant status. Additionally, if patients do not seek or purchase treatment, they are hard to be tracked.

When will we see a vaccine being used in the United States?

Because leprosy is such a small problem in the United States, and since 90% of cases are imported (immigrants from countries where leprosy is endemic), there is little reason for a leprosy vaccine to actually be utilized in the United States even if an effective vaccine is created. Once identified, patients with leprosy in the United States are immediately put on antibiotics and usually cured in six to nine months. However, this does not thwart the efforts of American researchers to continue in-depth research on future leprosy vaccines that can be used on an international level, and possibly help to eradicate leprosy in the future.

Kiyana Harris, Class of 2007, kjharris@stanford.edu
Stanford University
Parasites & Pestilence: Infectious Public Health Challenges
Prof. D. Scott Smith, ssmith@stanford.edu