A client who is 38 weeks pregnant is concerned her baby might get a communicable disease before any immunizations are given. Which physiological mechanism should the nurse use when responding to the mother’s concerns?

Choice A reason: Active immunity develops post-birth via exposure or vaccination, not fully in the first month; newborns rely on maternal antibodies, making this mechanism inaccurate. Choice B reason: Anti-infectants (e.g., antibiotics) treat infections but aren’t immunity; resistance is microbe-specific, and this doesn’t address natural newborn protection against communicable diseases. Choice C reason: Immature neutrophils increase infection risk, not protection; this highlights vulnerability rather than a mechanism safeguarding the baby, contrary to the mother’s concern. Choice D reason: Passive immunity from maternal IgG antibodies, transferred via placenta, protects newborns against diseases in early months until active immunity develops, addressing the mother’s worry.