Injecting the century-old tuberculosis vaccine straight into the veins could make the shot far more protective.
In research conducted on monkeys, scientists found that there was little to no inflammation in the lungs of those that received the vaccine straight into the bloodstream compared to today's skin-deep shot.
What's more, the majority of primates who received the shot like an IV had 100,000 times fewer bacteria in their lungs.
Researchers say administering the shot in this new way could drive down death rates of tuberculosis, which is currently the leading infectious cause of death worldwide.
Monkeys in the top row received skin-deep TB vaccines, while monkeys in the bottom row received shots straight into the bloodstream. The intravenous vaccine protected far better, as shown by TB-caused inflammation seen in red and yellow
Tuberculosis (TB) is a disease that affects the lungs and is caused by bacteria known as Mycobacterium tuberculosis.
When someone with TB coughs, sneezes or talks, infected droplets are sprayed into the air, where other people can inhale them and are then infected.
It cannot be spread, however, by shaking someone's hand, sharing food or beverages, or even kissing.
Symptoms include a cough that lasts for at least three weeks, chest pain, weakness, fatigue, fever and coughing up blood or mucus.
If left untreated, TB can spread throughout the body, causing inflammation, liver and kidney problems, and meningitis - and ultimately be fatal.
TB kills about 1.7 million people a year, more than any other infectious disease in the world and mostly in poor countries.
The only approved vaccine, called the BCG vaccine, is used mainly in high-risk areas to protect babies from one form of the disease.
But it's far