H3N2 Symptoms: Doctors have reported a disturbing rise in H3N2 cases among children. Classic symptoms of H3N2 infection include cough, cold, body ache, diarrhea, vomiting, and fever. Fever in some cases could go as high as 104-105 F, vomiting, loose motion, cough/cold, and in extreme cases convulsions and drowsiness. Symptoms usually last for 5-7 days. A persistent cough can also be seen in some patients lasting for a longer period. The doctors also advised people to get regular flu vaccines every year, use masks, wash hands regularly and stay away from crowded places which act as a medium for the super spread of the virus. Watch Video.