How should the nurse respond to a parent who asks, "How can I protect my baby from whooping cough?"

A. Vaccination is the primary prevention for pertussis (whooping cough). Infants receive the DTaP series starting at 2 months of age, which provides protection against the disease. Ensuring timely immunizations is the most effective method to protect the baby. B. Maternal immunity is partial and short-lived, typically waning within the first few months of life. It does not provide protection until 18 months, so relying on maternal antibodies alone is inadequate. C. Prophylactic antibiotics for contacts are recommended only in specific exposure situations, not as routine protection. Vaccination remains the main preventive measure. D. Prescribing erythromycin is used for treatment or post-exposure prophylaxis in certain cases but is not a primary preventive strategy for all infants. E. Waiting until the baby develops symptoms does not prevent infection and may result in severe illness, especially since infants are at high risk for complications from pertussis.