INFLUENZA A+B; IMMUNIZATION BREAKTHROUGH ON 30/01/2023 CONFIRMED BY SMEAR WITH POSITIVE INFLUENZA DETECTION IN A PEDIATRICIAN: DIAGNOSIS OF STATUS FEBRILIS, INFLUENZA POSITIVE AFTER VACCINATION IN DECEMBER 2022. PATIENT WAS VACCINATED 2 TIMES WITH FLUENZ TETRA I...; A spontaneous report has been received from a physician concerning a male patient of Unknown ethnic origin (age 5 years, height 112 cm, weight 19 kg).    On 23-Dec-2022, The patient received Fluenz Tetra (influenza vaccine live reassort 4v) as a booster, (2021 + 2020 flu vaccine already received) (batch number PH3536B) (expiration date 04-Jan-2023), via nasal route.     A unknown administered FLUENZ TETRA. No malfunction has been reported for this combination product.    On 27-Jan-2023, the patient experienced influenza a+b (preferred term: Influenza) and immunization breakthrough on 30-Jan-2023 confirmed by smear with positive influenza detection in a pediatrician: diagnosis of status febrilis, influenza positive after vaccination during Dec-2022. patient was vaccinated 2 times with fluenz tetra i.(preferred term: Influenza virus test positive). Patient also infected both parents with influenza. Both parents developed influenza .    On an unknown date, symptomatic therapy of influenza with ibuprofen + decongestant nasal spray    Treatment with Fluenz Tetra was not changed.     The patient recovered from the event of immunization breakthrough on 30/01/2023 confirmed by smear with positive influenza detection in a pediatrician: diagnosis of status febrilis, influenza positive after vaccination in december 2022. patient was vaccinated 2 times with fluenz tetra i... after 1 week on 02-Feb-2023.   On an unknown date, patient recovered from the event of  influenza a+b.    Company physician assessed event of  influenza a+b as serious due to important medical event and event of  immunization breakthrough on 30/01/2023 confirmed by smear with positive influenza detection in a pediatrician: diagnosis of status febrilis, influenza positive after vaccination in december 2022. patient was vaccinated 2 times with fluenz tetra i. as non-serious.    The reporter considered that there was a reasonable possibility of a causal relationship between Fluenz Tetra and the following event: immunization breakthrough on 30/01/2023 confirmed by smear with positive influenza detection in a pediatrician: diagnosis of status febrilis, influenza positive after vaccination in december 2022. patient was vaccinated 2 times with fluenz tetra i....     Device Information:     Combination Product Report: Yes    Product As Reported: FLUENZ TETRA  Common Device Name: Nasal Spray  Procode: CCQ  Product Role: Suspect    Follow up information received by AstraZeneca/MedImmune on 27-Mar-2023 from Physician via Spontaneous source was upgraded to serious: Primary reporter updated to physician, case was medically confirmed. Patient history added. Family history added. New serious event of influenza a+b added. Narrative amended.; Sender's Comments: Influenza is not listed in the company core data sheet of Q/LAIV. Previous history of Influenza could be considered as confounding factor to the event. Due to limited information on circumstances leading to event, details and clinical course of the event, concomitant medications, concurrent conditions, risk factors, baseline health and performance status, further diagnostic workup (complete blood panel, infectious workup, immunological workup); the evaluation did not find evidence to suggest a causal relationship between the event and suspect drug.