What is the most concerning statement a parent could make regarding a child who received the DTaP vaccine?

A parent stating that their baby is crying continuously after receiving the DTaP vaccine is particularly concerning because it may indicate the presence of significant distress or an adverse reaction. While mild irritation, decreased appetite, and a low-grade fever are common and often expected responses to vaccinations, persistent crying can suggest discomfort that goes beyond typical side effects.

In the context of childhood vaccinations, incessant crying that lasts for more than three hours is classified as a potential adverse reaction known as "persistent crying" or "excessive crying." This level of distress might warrant further evaluation from a healthcare provider to rule out any serious complications or underlying issues that could require medical attention.

The other statements made by the parent, while they may indicate mild side effects, are generally considered normal post-vaccination reactions. Redness at the injection site is a common local reaction and is typically not a cause for concern. A fever of 101°F is also a common response, as fevers can occur as the immune system responds to the vaccine. Similarly, decreased appetite can occur temporarily due to general malaise after vaccination, but it is not inherently alarming unless it persists or is accompanied by other concerning symptoms.