The latest efforts to improve the tuberculosis vaccine have ended in failure.
The MVA85A booster was intended to enhance the only existing tuberculosis vaccine available, BCG, but scientists were unable to find any evidence that it helped protect newborn infants.
Since BCG is only moderately effective against TB, there are research teams spanning the globe that are hard at work creating new vaccines. MVA85A was the first to be tested, to less than ideal results.
"It's pretty disappointing," said Dr. Jennifer Cohn, a medical coordinator at Doctors Without Borders, in an article by the Associated Press. "Infants are at really high risk of TB but this doesn't seem to offer them any protection."
Others agreed with Cohn's assessment, but noted that MVA85A is just one of the new vaccines that will be tested.
"This is a very disappointing result, but this was just the first of around 12 new tuberculosis vaccines currently being tested in humans and around 50 vaccine candidates currently being tested in the lab," said Dr. Richard White, an epidemiologist at the London School of Hygiene & Tropical Medicine, to the BBC. "It was a historic trial, the first of a new TB vaccine for nearly a century. It will lead to much valuable knowledge to help us design effective vaccines in the future.
Developed at Oxford University, MVA85A was tested in almost 3,000 babies in South Africa who had already received the BCG vaccine. Half of the babies received a placebo, while the other half took the vaccine. After a three-year follow-up and an effectiveness of just 17 percent, the trial was deemed unsuccessful.
Still, the effort might not be a complete bust. Since the immune system of an adult operates differently than that of a child, it's possible the new vaccine will still work in older people.
"If this vaccine is effective in adults, that would be hugely valuable because the majority of TB disease and deaths are among adults," said Dr. White. "But no one knows the answer to that right now."
Even if it's not, though, Dr. White said the money spent on research and development is incredibly important; it should not be stopped just because of a few failures. It costs more than $4 billion to treat TB every year, while only $650 million has been spent on the creation of new vaccines over the last 10 years.
