What is an example of passive immunity that a nurse can explain to a new mother concerned about allergies?

Passive immunity is a form of immunity that occurs when antibodies are transferred from one individual to another. In the context of a new mother and her infant, breastfeeding is an excellent example of passive immunity. When a mother breastfeeds, she provides her baby with antibodies found in her breast milk. These antibodies, particularly immunoglobulin A (IgA), help protect the infant from infections and diseases by providing immediate immune protection without the infant's immune system needing to produce the antibodies itself.

This transfer of antibodies through breast milk can also help reduce the likelihood of allergies in the infant, as the maternal antibodies can help modulate the baby's immune response as it adapts to its new environment. Breastfeeding also encourages the development of the infant's gut microbiome, which is important for long-term health and can further influence immune responses.

Other options like early immunization, bone marrow donation, and exposure to communicable diseases do not illustrate passive immunity. Early immunization involves introducing antigens to stimulate an active immune response in the individual, bone marrow donation is related to producing immune cells rather than transferring existing antibodies, and exposure to communicable diseases typically leads to the development of active immunity, where the individual's immune system responds to pathogens by creating its own antibodies.