The nurse takes a call from a concerned mother whose infant received routine immunizations the day before and now has a temperature of 101°F (38.3°C), is fussy, and pulling at the injection site. The mother wants to know what she should do. Which is the best response from the nurse to this mother?

Choice A reason: Offering ice cold fluids is not a recommended intervention for post-immunization discomfort. Covering the injection site may be appropriate if the child is scratching excessively, but it does not address the systemic symptoms like fever and fussiness. The advice lacks evidence-based comfort measures and may mislead the parent. Choice B reason: This response is the most appropriate and evidence-based. Mild fever, fussiness, and localized discomfort are common after routine immunizations. Acetaminophen helps reduce fever and pain, cuddling provides emotional comfort, and a cool compress soothes the injection site. These interventions are safe and effective for managing typical post-vaccine reactions. Choice C reason: A temperature of 101°F and fussiness alone do not indicate an allergic reaction. True allergic reactions typically involve symptoms like hives, difficulty breathing, or swelling of the face and lips. This response may unnecessarily alarm the parent and lead to unwarranted emergency visits. Choice D reason: While it is true that many infants experience mild reactions, this response lacks specific guidance and reassurance. Telling the parent to "call back" without offering comfort measures or education does not reflect best nursing practice and may leave the parent feeling unsupported.