Protective injection for flu = 2600 yen ($21.49 €17.45)

Today my kids got protective injections (immunization shot) for flu at a clinic. It cost 2600 yen ($21.49 €17.45) for one shot. Over 13 years old person, one shot is enough to acquire immunity. Under 12 years old person, two shot are required. My son has to get two shots. He will go to the clinic again, and has to pay more 2600 yen.