Worldwide, a person dies from tuberculosis (TB) every 18 seconds, according to the TB Alliance. Now initial trials suggest that a new vaccine could save millions of lives. A final analysis of a TB vaccine trial published October 29, 2019, in The New England Journal of Medicine (NEJM) found the treatment to have a 50 percent efficacy rate. “Cutting cases by 50 percent is a significant victory,” says Len Horovitz, MD, a pulmonary specialist at Lenox Hill Hospital in New York City. “You always want 100 percent effectiveness with every vaccine, but that’s not realistic. The flu shot for example is about 60 percent effective in warding off the flu for people.”
An Early Study With Significant Results
For the trial, a total of 3,330 participants living in active tuberculosis disease centers in Kenya, South Africa, and Zambia received both doses of the GlaxoSmithKline inoculation called M72/AS01E. After three years of study, 13 individuals had developed active pulmonary tuberculosis, as compared with 26 in the control group. William Schaffner, MD, an infectious disease specialist and professor of preventive medicine and health policy at the Vanderbilt University School of Medicine in Nashville, Tennessee, recognizes that those numbers are small but still significant. “This is a small study that is proof of concept,” he says. “The illness is so important, and the potential advance is so important that the NEJM decided to publish it even though it is an early, small study.” Because larger studies need to be done, Dr. Schaffner predicts that the vaccine will not be available to the public for many years. In an interview with the BBC, David Lewinsohn, MD, PhD, a professor of medicine in the division of pulmonary and critical care at the Oregon Health and Science University in Portland, estimated that it would be at least eight years before the vaccine is ready. “I think having it ready in that time is ambitious,” says Schaffner. “There is not only an effectiveness component to be tested but also a safety component.” This new TB vaccine is not the first. The CDC notes that a vaccine for TB called BCG is already available to the public, but it works best only against the most severe cases (as in TB meningitis in children) and it does not work very well in adults, according to the U.K. National Health Service.
A Highly Transmittable Illness: What Is Tuberculosis?
Tuberculosis is an airborne illness that is typically transmitted by coughing or sneezing. It often takes prolonged face-to-face contact to spread. But in circumstances where people live close to each other, everyone can get infected, according to Schaffner. That’s a major reason why 10 million people fell ill with TB last year and 1.6 million died, according to the TB Alliance. The disease is characteristically an infection of the lungs that causes lung destruction and progressive disability, but the bacteria can also disseminate throughout the body and cause localized infections in other parts of the body. The World Health Organization reports that Southeast Asia and Africa are regions most affected by the disease. Women, children, and people with HIV or AIDS are most susceptible. “There is no immune protection with HIV, so tuberculosis can make huge inroads with a person,” says Dr. Horovitz. “They don’t fight off infections that other people don’t get, so they are very susceptible.” In the United States, HIV patients are more likely than others to get the disease. Although cases are fewer in America compared with other regions, the Centers for Disease Control and Prevention (CDC) reports that there were 9,105 cases in 2017. “Still, too many people suffer from TB disease and our progress is too slow to eliminate TB in this century,” writes the CDC. “Ending TB will require maintaining and strengthening current TB control priorities while increasing efforts to identify and treat latent TB infection in high-risk populations.” An effective vaccine has the potential to help alleviate the problem both in this country and abroad. “Along with a malaria, HIV, and universal flu vaccine, an effective tuberculosis vaccine is one of the holy grails of vaccines,” says Schaffner. “Way down the road, it could prevent many, many serious illnesses and deaths.”
