Final answer:
A neonate's initial protection against diseases such as measles, mumps, and rubella due to maternal antibodies is an example of passive immunity. This natural protection comes from antibodies transferred from mother to child, providing immediate but temporary protection.
Step-by-step explanation:
When a neonate is protected against diseases like measles, mumps, and rubella because of the immunity passed down from the mother, this is an instance of passive immunity. The protection the newborn receives is a result of the antibodies, like IgG and IgA, which are transferred across the placenta and found in breast milk. These antibodies provide immediate protection to the infant by the mother's previously developed immune response without the requirement for the infant to produce its own antibodies. This type of immunity is temporary as the transferred antibodies will degrade over time, and the infant will eventually need to form its own active immune response to pathogens.
On the other hand, vaccinations trigger artificially acquired active immunity because they stimulate the recipient's immune system to produce its own protective antibodies and immune cells, forming immunological memory in the process. This immunity is long-lasting compared to passive immunity.