How do you help a baby with a low immune system?

Immune function. You need to know if it is transient hypogammaglobulinemia of infancy (thi) or a specific immunodeficiency. A good diet, multivitamin, an excellent pediatrician and immunologist are essential too.
Avoid Exposure. Avoid unnecessary exposure to infections; this includes good hand-washing by everyone involved in the baby's care; influenza vaccination for all caregivers; breast feeding if possible; and avoiding daycare for the first year of life. Standard immunizations are important to be kept up to date.