Do infections help build immunity?
In the mature immune system, yes they do. This is the principle upon which many immunisations work whereby a small amount of the disease-causing organism is introduced to enable the body to create protective anti-bodies, which remain in the blood stream. The immunisation that babies will receive during their first few months will help them to establish antibodies that will help fight a range of baby illnesses. However it makes sense to try to do all you can to prevent babies getting these illnesses, especially those that can cause gastroenteritis. Therefore it is a good thing to give the extra protection that their immune system cannot provide until they are older and stronger.
