This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the parent. Other Case identifier(s): US-PFIZER INC-202101721174. A 5 year-old male patient received bnt162b2 (COMIRNATY), administered in arm left, administration date 23Nov2021 (Lot number: FK5127) at the age of 5 years as dose 1, single for Covid-19 immunisation. Relevant medical history included: "autism" (ongoing), notes: Diagnosed with autism at age 3 years old and this is mostly the reason he got Pfizer Covid vaccine. There were no concomitant medications. The following information was reported: SOMNOLENCE (non-serious) with onset Nov2021, outcome "recovered" (Nov2021), described as "sleepy"; VOMITING (non-serious) with onset Nov2021, outcome "recovered" (Nov2021), described as "vomiting/puking"; SKIN DISORDER (non-serious) with onset Nov2021, outcome "recovered" (Nov2021), described as "bump near his ear/had sort of a bump by the side of his ear and another bump near his cheek"; ASTHENIA (non-serious) with onset Nov2021, outcome "unknown", described as "he did not have any energy"; RASH (non-serious) with onset 26Nov2021, outcome "recovering", described as "the bumps the patient had were more like a rash"; DECREASED APPETITE (non-serious) with onset Nov2021, outcome "recovered" (Nov2021), described as "did not want to eat or drink anything"; FLATULENCE (non-serious) with onset 23Nov2021, outcome "unknown", described as "a lot of gasses". The event "vomiting/puking" was evaluated at the physician office visit and emergency room visit. The event "did not want to eat or drink anything" was evaluated at the emergency room visit. The event "a lot of gasses" was evaluated at the physician office visit. Relevant laboratory tests and procedures are available in the appropriate section. Therapeutic measures were taken as a result of vomiting, asthenia. Additional information: As noted in the Fact Sheet for Recipients, you should not get the Pfizer-BioNTech COVID-19 Vaccine if you had a severe allergic reaction after a previous dose of the vaccine or if you had a severe allergic reaction to any ingredient of the vaccine. The decision to receive the second dose for any other reason cannot be made by Pfizer. We refer you to speak to your healthcare provider about the risks of the vaccine compared to the risks of potentially not being fully protected against COVID-19 infection. Your healthcare provider knows your health situation and has access to information that can better help inform this decision. The following adverse reactions have been identified during post authorization use of Pfizer-BioNTech COVID-19 Vaccine. Because these reactions are reported voluntarily, it is not always possible to reliably estimate their frequency or establish a causal relationship to vaccine exposure. Cardiac Disorders: myocarditis, pericarditis, Gastrointestinal Disorders: diarrhea, vomiting. States the patient got the Pfizer Covid vaccine last week and before Thanksgiving she had taken him to the pediatrician who recommended the vaccine and said it was a good idea to get the vaccine and it was fine and safe and states the patient got the vaccine on 23Nov2021 and Wednesday he woke up and was fine and she thought oh he didn't feel anything that is good and on Thursday he woke up and was puking and did that Friday and Saturday and then she took him to the emergency room. States the patient is not currently vomiting but on Saturday she decided to take him to the emergency room but he was like that for 2-3 days and they put him on something with an IV and did an x-ray on his stomach and did a blood exam and checked his haemoglobin to see if it was fine or if he was dehydrated; states on Saturday he did not take water or retain any liquid or anything and the exam did say he was not aneamic or dehydrated and that was fine so they put some saline in an IV because he was very down. States he did not have any energy and they gave him the IV so he could get better. Caller states the bumps the patient had were more like a rash because it was small but one was like a stain on his cheek and was a bit bigger and more like a rash and she took pictures of the rash; states the rash is very minimal now but is still there and not completely gone away and he has just a little bit of the rash but it is mostly gone away and is very little; states the patient is special and has trouble with food and had very little food and she got worried at that time because he got these things before regarding the bumps and states he mostly gets a fever when that happens and the next day too and states she was very worried because of that; states the rash began around Friday 26Nov2021; despite further attempts at clarification, captured as stated by the caller. No follow-up attempts are possible. No further information is expected.