The first new TB vaccine for 80 years, designed by researchers at Oxford University, is being given to nearly 3000 infants in South Africa to test its effectiveness.
Researchers say the current vaccine, the familiar and widely used BCG, is not effective enough, with 1.5 million people worldwide still dying from TB each year.
The new experimental vaccine is called MVA85A. It can be used on its own, or as a booster in conjunction with the BCG.
Dr Helen McShane, who led the vaccine research, said: “This trial will hopefully show that the vaccine can protect people from getting TB.”