My baby is having cold since a month now, it's not constant, but it comes and goes, twice cold has led to infection which he recovered after course of antibiotics, but his cold doesn't seem to go away as soon as I take him out he catches cold how can I built his immunity? Giving him zincovit every day.and he is having head bath everyday he is 4month old, and he is bald is this reason of he catching cold so soon???