1. What is infant immunity? Infant immunity refers to the natural immunity that newborns have at birth and the immunity they acquire later in life. When a newborn is born, his or her immune system is not fully developed, but it gradually grows and develops over time. During this process, parents can take some measures to enhance their baby\’s immunity and help them better resist viruses and bacteria. 2. How to enhance your baby’s natural immunity? 1. Breastfeeding: breast milk