It does provide some protection, but not so much that I would have felt comfortable bringing my infant on a plane all the way across the country. For example, breast milk antibodies don't seem to protect against whooping cough Paper on breast milk antibodies and whooping cough which is so dangerous in young babies.
But we all know that Kail's kids, while better cared for than many of the Teen Mom babies, still take a back seat to anything Kail wants for herself.