SCIENCE

In Search of a Tuberculosis Vaccine

July 1, 2010

When I told a co-worker yesterday that I was going on a tour of a tuberculosis vaccine research facility, she asked, "is TB still a problem?" Here in the United States, the disease is rare—only 12,904 cases were reported in 2008—and generally treatable with antibiotics. Outside of North America, Australia and much of Europe, however, the disease still runs rampant. One third of the world's population is infected with a strain of Mycobacterium tuberculosis, and nearly nine million become sick with TB each year. Two million die from the disease, and it is the leading killer of individuals with HIV.

I knew TB was a horrible disease before I showed up with other members of the DC Science Writers Association last night at Aeras Global TB Vaccine Foundation—I read with fascination this story about the country's last TB sanitarium just a few weeks ago—but I hadn't realized just how bad it truly is. And this despite the fact that there are treatments for the disease and even a vaccine, BCG, that's been around since the 1920s. That's obviously not enough to control the disease: treatment is expensive and requires many months of daily pills, the BCG isn't very effective, and many strains of the bacterium have developed resistance to various antibiotics. So what do we do?

Aeras, with funding from the Gates Foundation and others, is working to develop a new vaccine regimen to bring TB under control. One modeling study estimated that a new vaccine regimen could reduce TB cases and deaths in Southeast Asia by 75 percent by 2050. But creating that new vaccine requires a lot of research and testing, much of it being done by Aeras just outside Washington, D.C.

We toured their facility, peeking into the discovery labs where molecular biologists design new vaccines, visiting laboratories where scientists figure out how to scale up production, and even donning labcoats, safety glasses and blue booties to troop through their manufacturing facility (shut down for summer maintenance) to see how vaccines are made (in giant vats) and bottled.

The strategy for a new vaccine regimen is called "prime-boost." Infants would be given a modified, improved version of the BCG vaccine—the "prime"—and then older children would be given a "boost" with a second vaccine, a virus engineered to enhance and extend protection. All these vaccines are still in development, with several versions of the boost being tried out in several countries, so it will be years before we'll see world health officials spreading out to administer any new regimen. However, I was heartened to see so many smart, creative people tackling a problem most of us in this country don't even realize exists.