Is the 100-year old TB vaccine a new weapon against Alzheimer’s?

Studies suggest the BCG jab discovered a century ago could provide a cheap and effective way of boosting the immune system to protect people from developing the condition

Scientific discoveries can emerge from the strangest places. In early 1900s France, the doctor Albert Calmette and the veterinarian Camille Guerin aimed to discover how bovine tuberculosis was transmitted. To do so, they first had to find a way of cultivating the bacteria. Sliced potatoes - cooked with ox bile and glycerine - proved to be the perfect medium.

As the bacteria grew, however, Calmette and Guerin were surprised to find that each generation lost some of its virulence. Animals infected with the microbe (grown through many generations of their culture) no longer became sick but were protected from wild TB. In 1921, the pair tested this potential vaccine on their first human patient - a baby whose mother had just died of the disease. It worked, and the result was the Bacille Calmette-Guerin (BCG) vaccine that has saved millions of lives.