Children often get sick after receiving the flu vaccine, which may be a sign that their immune system is working hard.

Kidney syndrome is a common kidney disease, primarily related to autoimmune reactions, characterized by symptoms such as excessive proteinuria. It is recommended to seek treatment at a regular hospital as soon as possible.

Children who often catch colds may have weakened immunity, so it is recommended to engage in more physical activities and supplement nutrients appropriately to boost immunity.

Frequent fevers in children could be a sign of weakened immune systems.