Bacillus Calmette-Guérin (BCG) is one of the world’s oldest and most widely used vaccines. It was developed in the early 20th century to provide protection from tuberculosis. Surprisingly, this ...

“Have I had coronavirus and, if so, am I immune?” It’s the question many of us are asking – but sadly it isn’t an easy one to answer. Immunity is defined as being able to resist a particular disease.