Neck hurts; Back of neck a little puffy; still hurts a little in the back; Neck has been pretty stiff/ couldn't just turn his neck; This is a spontaneous report from a contactable consumer (patient's mother). A 25-year-old male patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE), the second dose via unspecified route of administration in left deltoid on 03May2021 at 15:00 (lot number: EW0173) at single dose for COVID-19 immunization. The relevant medical history included autism from 07Dec1997 and ongoing (diagnosed with autism when he was 2 years and 3 months old/ able to get the patient into early intervention), bipolar disorder from 2016 and ongoing, anxiety from 2016 and ongoing, allergies from unspecified date and ongoing (has always struggled with allergies), psoriasis from Apr2020 and ongoing (the patient came to the doctor after nothing was working for what they thought was eczema. The patient went to a specialist and was just recently having flare ups and they took a biopsy to see if it was something else, but the result was leaning heavily to psoriasis. The patient sometimes needs Kenalog or steroid injections to suppress if there is a flare-up, but it's better), mood stabilizer from unspecified date, broke his foot from unspecified date (playing basketball in the Special Olympics and went 2 weeks without saying anything). Concomitant medications included valproate semisodium (DEPAKOTE) from 2016 and ongoing for bipolar disorder; asenapine maleate (SAPHRIS) from 2016 and ongoing for mood stabilizer; hydroxyzine from 2016 and ongoing for anxiety; loratadine from 2016 and ongoing for allergy; ixekizumab (TALTZ) from Apr2020 and ongoing for psoriasis. The patient previously received flu vaccine on an unspecified date (patient had a flu vaccine but that was back in flu season) and the first dose of BNT162B2 (Lot Number: ER8737; Anatomical Location: Left Deltoid) on 31Mar2021 at the age of 25 years old for COVID-19 immunization. The consumer reported that her adult autistic son, the patient, had the Covid-19 vaccine. Caller reported that the patient went for his checkup last week and the caller mentioned that the patient's neck had been pretty stiff since receiving the second dose of the Covid-19 vaccine. Caller reported that the patient's doctor said that she should call the line for Pfizer and report it. Caller reported that when the patient turns his neck, he says that it still hurt a little in the back. Neck had been pretty stiff: Caller reported that the patient couldn't just turn his neck, he turned the whole body. Caller reported that she noticed that the patient was turning his whole body and she asked him why he was not turning his neck. Caller reported that the patient responded that he thought he was just turning his neck. Caller reported that it wasn't immediately after the second dose that the patient developed the stiff neck. Caller reported that some weeks went by and she started to notice it. Caller reported that she couldn't think of any other thin that could have caused the patient's stiff neck. Caller reported that she asked the patient if he had curled up funny. Caller stated that she didn't even think to call and report the patient's stiff neck until his physician recommended that she call. Caller reported that originally, it seemed like the back of the patient's neck was a little puffy but it isn't any more. Caller reported that the patient was seen at the hospital. Caller reported that the physician there prescribed the patient's meds. Caller reported that he did see another doctor there about once a year for a physical, but he primarily saw them for med checks every 3 months. She didn't think about reporting the patient's stiff neck and that's the only issue. Caller reported that the patient has never had issues with other medications. Caller reported that the pain was just in the patient's neck area and he was doing fine otherwise. Caller reported that the patient had a very high tolerance for pain. Caller reported that the patient typically didn't complain, but he did complain about his neck. Neck had been pretty stiff: Caller reported that she noticed that the patient's neck seemed stiff about 2 weeks after the second dose of the Covid-19 vaccine. Caller reported that she didn't think that that the Covid-19 vaccine could have caused the patient's stiff neck. Caller reported that she was asking the patient why he was moving so stiff, then she thought 3 weeks ago maybe it's connected to the Covid-19 vaccine. Caller reported that the patient's stiff neck was about the same. Caller reported that the patient was still turning stiffly but stated that he was trying to turn his neck. Caller reported that she didn't think that the patients neck hurt as much. Caller reported that the patient stated that his neck hurt just a little, but he had a high pain threshold. The patient underwent lab test included biopsy on his wrist: didn't even flinch on an unspecified date in 2021 (biopsy on his wrist  few weeks ago and didn't even flinch); Biopsy: leaning heavily to psoriasis on an unspecified date; blood work: fine (to watch his liver and all that for the Depakote, and he's been fine) on an unspecified date. The outcome of the event back of neck a little puffy was recovered on an unspecified date in 2021, while other events were not recovered.  Follow-up attempts are completed. No further information is expected.