Replied by Timh (Ky, US) on 11/27/2014
Arginine is said to increase the size and activity of the Thymus Gland (which is the brain of the immune system), but it also promotes viral replication as well as fuel for mycoplasma infection. So, this see-saw balance seems to leave the matter in a neutral zone of benefit vs bad side effect.
There are other methods for Thymus boosting and most diets are already sufficient or abundant in Arginine. On-the-other-hand, supplementing Lysine would be indicated during any viral infection.
