Dizzy; Nosebleeds; Nosebleed was reported as worsened; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non-HCP). The reporter is the parent.  A 14-year-old male patient received bnt162b2 (BNT162B2), administered in arm left, administration date 13Jan2022 17:30 (Lot number: FIC9729) at the age of 13 years as dose 3 (booster), single for covid-19 immunization. Relevant medical history included: "Nosebleed" (unspecified if ongoing). Concomitant medication(s) included: INFLUENZA VACCINE taken for immunization, administration date 30Dec2021. Vaccination history included: Bnt162b2 (Dose number: 1), administration date: 17May2021, when the patient was 13 years old, for COVID-19 Immunization, reaction(s): "he had no reaction to the first or second shot"; Bnt162b2 (Dose number: 2), administration date: 07Jun2021, when the patient was 13 years old, for COVID-19 Immunization, reaction(s): "he had no reaction to the first or second shot"; Flu shot (Dose: 1, No. of Previous Doses: 2); Flu shot (Dose: 2, No. of Previous Doses: 2). The following information was reported: EPISTAXIS (non-serious) with onset 14Feb2022 17:00, outcome "not recovered", described as "Nosebleeds"; CONDITION AGGRAVATED (non-serious) with onset 14Feb2022 17:00, outcome "not recovered", described as "Nosebleed was reported as worsened"; DIZZINESS (non-serious) with onset 18Feb2022, outcome "recovered" (25Feb2022), described as "Dizzy". The events "nosebleeds" and "nosebleed was reported as worsened" were evaluated at the physician office visit. Therapeutic measures were taken as a result of epistaxis, condition aggravated.  Additional information: No History of previous immunization with the Pfizer vaccine considered as suspect. No Additional Vaccines Administered on Same Date of the Pfizer Suspect. Prior Vaccinations (within 4 weeks) or other vaccinations within four weeks prior to the first administration date of the suspect vaccine included: Flu shot. The patient had Flu shot two weeks before booster. Stated that she thinks that it was around 30Dec2021. The reporter stated that on 13Jan2022, her 14-year-old son got the Pfizer booster shot on left upper arm. Stated that he had no reaction to the first or second shot. Stated that since he got the Pfizer booster shot that his nose has been bleeding and they cannot get it to stop. Stated that they went to the pediatrician and was sent to a pediatric ear, nose and throat doctor who sent them to a hematologist/oncologist. Stated that she has not received those results not until 16Mar. Stated that his last one lasted one hour and was hard to clot. Stated that he gets dizzy. Stated that traditionally he got a nosebleed when he was sick with any type of cough, cold, flu or pneumonia but never bled when he was healthy and not sick. Stated that she does not know if the Pfizer booster caused that or not but felt that she should report. Stated that the timing of getting the Pfizer booster shot was close. Stated that he got nosebleeds the day after the Pfizer booster shot. Stated that he got the Pfizer booster shot on 13Jan and his nose started to bleed the next day. Stated that with the last nosebleeds that he got dizzy with them but not at any other time. Stated that he got dizzy with the nose bleeds on 18Feb2022 and 25Feb2022. Stated that he has had two nose since then but has not reported any since. Stated that the nosebleed on 25Feb2022 was an hour-long nosebleed. Stated that they would go back to hematologist on 15Mar2022. Stated that they have not been able to determine the cause yet. Stated that they have been using Afrin, ice and pressure for the nosebleeds. Stated that he had rest for the dizziness.   No follow-up attempts are possible. No further information is expected.