inflammation of the lining of the heart; had a difficult night sleep; shortness of breath/struggling to breathe; palpitations; first jab on 21Aug, 04Dec a second vaccination; has been turned upside down. He can't go to the cinema. He had a party to go to can't do anything; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP). The reporter is the parent.  A 17 year-old male patient received bnt162b2 (BNT162B2), administration date 04Dec2021 (Batch/Lot number: unknown) as dose 2, single for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Bnt162b2 (Dose 1, single, Had no reaction to his first jab), administration date: 21Aug2021, for Covid-19 Immunization, reaction(s): "No adverse Effect". The following information was reported: CARDITIS (hospitalization, medically significant) with onset Dec2021, outcome "unknown", described as "inflammation of the lining of the heart"; INSOMNIA (non-serious) with onset 08Dec2021, outcome "unknown", described as "had a difficult night sleep"; DYSPNOEA (non-serious) with onset 08Dec2021, outcome "unknown", described as "shortness of breath/struggling to breathe"; PALPITATIONS (non-serious) with onset 08Dec2021, outcome "unknown", described as "palpitations"; IMPAIRED QUALITY OF LIFE (non-serious) with onset Dec2021, outcome "unknown", described as "has been turned upside down. He can't go to the cinema. He had a party to go to can't do anything"; INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (non-serious) with onset 04Dec2021, outcome "unknown", described as "first jab on 21Aug, 04Dec a second vaccination". The patient was hospitalized for carditis (start date: 06Dec2021, discharge date: 12Dec2021, hospitalization duration: 6 day(s)). The patient underwent the following laboratory tests and procedures: blood test: (Dec2021) unknown results; cardiac monitoring: (Dec2021) unknown results, notes: was put on a heart monitor; electrocardiogram: (Dec2021) unknown results, notes: three electrocardiograms (ECCS); (Dec2021) unknown results; (Dec2021) unknown results.  Clinical course: A distraught mum reported her 17-year old son's has been turned upside down after the patient suffered a rare severe reaction to a Covid 19 vaccination. spent six days in hospital with inflammation of the lining of the heart and was now confined to home for six weeks. The reporter warning other parents to be vigilant after the patient suffered shortness of breath and palpitations following second jab. A consultant at hospital confirmed symptoms were due to the vaccine and after the patient was discharged on Sunday (12Dec2021), was advised to rest with no strenuous activity, consultant told would recover in time, but the patient must not have the booster vaccine. The reporter stated, "He's been very poorly," "What's so traumatic was he's not allowed to move from the house for six weeks. The patient was a 17-year-old boy has been turned upside down. The patient can't go to the cinema, had a party to go to can't do anything. The reporter had gone on Saturday 04Dec2021 for a booster jab for her and husband and a second vaccination for the patient. The patient had no reaction to first jab on 21Aug2021. It was not until last Wednesday (08Dec2021) that patient had a difficult night's sleep because the patient was struggling to breathe and had started to have palpitations. After ringing, they turned down advice to attend Hospital, as the family had a complaint upheld over the care of dad four years ago, so reporter took the patient who was studying for A-levels in maths, computer science and business studies at withheld had three electrocardiograms (ECCS) and blood tests and was put on a heart monitor before the hospital confirmed the Pfizer vaccine was the cause. Reported staff at the hospital had been "totally amazing", but reporter was devastated over what the patient had to go through, stated "My child Was a guinea pig." she said, "I would never have put him through it, and if I could take the pain I would To see that kid lying in hospital. "This is the most crucial time in his education. I don't know how long it will be before we can have a normal life again. The reporter had been told the reaction patient suffered affected one in people, with young men most at risk. and she wants parents to know about the dangers and stated "I just want people to know that it's important to be vigilant.  The lot number for bnt162b2 was not provided and will be requested during follow up.