Abstract
This clinical study was initiated through our experience of relatively rare cases with post-influenza vaccine-induced anaphylaxis. We had a chance to start the study from several local patients with the anaphylaxis and then expanded the study at the national level. Through the further investigation of causes of the anaphylaxis, we were able to re-think the general precaution of vaccination to children with egg allergy, and gave the attention to the HA antigen itself not on the egg-derived antigens. While we were lucky enough to perform the study with sufficient supports from the patients and the medical staff, it is noted that a good clinical study should be conducted based on questions arose from the clinical practice without any biases, and sufficient communication and cooperation with patients.
