CMPA is an abbreviation for Cow’s Milk Protein Allergy. It is a hypersensitive reaction caused by cow’s milk-based products onto the immune system. For the babies with this allergy, opt for the Similac Lactose Free Infant Milk that is specifically catered for babies with CMPA. It is a soy-based, lactose-free formula milk, and still contains all the nutrients that you would typically get in a cow’s milk-based formula.