shaking like I had a chills/trembling; feeling real weak and tired; arm was sore; flashes; This is a spontaneous report from a contactable consumer or other non-hcp (Patient). A 44-year-old male patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Formulation: solution for injection; Batch/Lot Number: Unknown, Expiration date: Unknown) via an unspecified route of administration (Age at vaccination 44-year) in right arm on 04Mar2021 as dose 1, single for COVID-19 immunization. The patient medical history was not reported. Concomitant medication included testosterone taken for an unspecified indication, start and stop date were not reported. On an unspecified date in Mar2021 the patient experienced arm was sore and flashes, on 05Mar2021 the patient experienced feeling real weak and tired, on 11Mar2021 the patient experienced shaking like he had a chills/trembling. It was reported that "He used Testosterone gel. He had been on that about a year now. He used it every morning, it was recommended by the doctor 2 pumps of the gel and he rubs it on his upper arms. He was going to look up his prescription because there is a specific dosage in each pump. Each pump was 20.25 mg, and he uses 2 pumps once daily, 40.5 mg once daily total. He says he had a question; he was having a side effect and he was not sure if it was related to the vaccine. He had the first one, he hadn't had the second one, but he had the first 04 Mar and he felt sick, he felt real weak the next day. He was fine after that, that Friday his right arm was sore and that was sore for a couple days but that subsided, it was fine and then a week later 11Mar, he was trembling, his whole-body trembles and he had hot flashes as well and he does not know if it was related to the vaccine, but he had not been able to stop shaking since last Thursday. He was trying to see if that was associated with product. He confirms he had the first dose 04 Mar and the next day 05 Mar he had weakness. His arm was sore a couple days. He says all of that was recovered completely now. He says the trembling began 11Mar. He says hadn't had a fever, he was trying to explain, it feels like if he was fighting off an infection or something, there was constant shaking as if he did have the chills, but he doesn't. He had hot flashes like he will get hot then he will get cold, but he doesn't run a fever at all, there was constant shaking. Caller was a 44-year-old male who received his first dose of the Pfizer BioNTech COVID-19 vaccine on 4MAR2021 and reports that his arm was sore for a couple of days after. He then states that the next day he began to experience "feeling real weak and tired" but states that passed. He also mentions that that Saturday, his arm was no longer sore. However, the following week on a Thursday, he reports he was trembling and "shaking like he had a chill" but reports not having a fever. He states that it had been "constant shaking" since last week that will "ease up some" but does not fully go away. He also reports hot flashes where he will get cold and then get "real hot" but again reports no fever. Caller states that the only medication he tooks was testosterone gel once a day in the morning and had been taking this for about a year. Caller would like to know if there have been any other reports of this trembling and "constant shaking" after receiving a dose of the vaccine." The clinical outcome of "arm was sore, feeling real weak and tired" was resolved on an unspecified date in Mar2021; outcome of "shaking like he had a chills/trembling" was not resolved; outcome of another event was unknown.  Follow-up attempts completed. No further information expected.