Which statement about maternal antibodies and infant infection risk is correct?

• A. Yes, your infant is protected from all infections
• B. If you breastfeed, your infant is protected from infection
• C. The transfer of your antibodies protects your infant until the infant is 12 months old
• D. The immune system of an infant is immature, and the infant is at risk for infection

Answer: (D)

Infants rely on maternal antibodies only temporarily while their own immune system matures. Maternal IgG crosses the placenta to provide passive protection during early life, and breast milk supplies secretory IgA that helps defend mucosal surfaces, but neither form offers complete protection against all infections or lasts for the full first year. As these maternal antibodies wane and the infant’s immune system is still developing, the infant remains at higher risk for infections. This is why the statement that the infant’s immune system is immature and the infant is at risk for infection is the most accurate reflection of infant immunity.