The World Health Organization recently released a report on the daunting numbers of tuberculosis infections. It wasn’t too long ago that scientists thought that tuberculosis was on the verge of being wiped out, but complacence about the disease as well the HIV/AIDS epidemic led to a resurgence of the disease. According to WHO regional director in Southeast Asia, Uton Muchtar Rafei, “an estimated 40 percent of the population is infected with TB in our region and more than 1.5 million people died of TB last year.”
Worldwide, tuberculosis is the second leading cause of death from a single infectious agent.
When TB was last a major epidemic, at the turn of the century, a tuberculosis vaccine was created and refined from 1906-1919. The only problem was that it was only about 50 percent effective. Now researchers at the University of California-Los Angeles believe they may have created a much more effective vaccine.
Dr. Marcus Horwitz at UCLA led a study of the new vaccine that involved taking samples of the old vaccine and genetically modifying it to add a protein that is secreted from the organism that causes tuberculosis. “Most proteins of a bacteria are inside,” Horwitz told Reuters, “but there are some proteins which are actually excreted.”
Researchers then infected guinea pigs with tuberculosis, injecting half of them with the new vaccine and leaving the others unvaccinated as a control group. “The difference between the unvaccinated guinea pigs and those that were vaccinated is just day and night,” Horwitz said. “The unvaccinated animals, their lungs just became completely covered with tubercules and destroyed and the animals with the vaccine have one or two lesions which are contained.”
Testing should begin within a year to see if the vaccine is effective in human beings. If so, Horwitz said it should be able to be produced for just pennies a dose. The only drawback is that the vaccine won’t help people with AIDS since the vaccine could potentially disease itself in people with compromised immune systems.
Sources:
WHO finds TB, malaria return in killer diseases. Reuters, November 27, 2000.
Vaccine may work against tuberculosis. Reuters, November 30, 2000.