Passed out; Vertigo; Nausea; felt like he was going to pass out; Lost 12 pounds since getting the second shot; 103 fever; Severe chills/Shivering uncontrollably; Every inch of body ached; Headache; Low back pain; could barely walk; Blood in stool; This is a spontaneous report from a contactable consumer (patient). A 59-year-old male patient received the second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, lot number: ER8729), via an unspecified route of administration, administered in left arm on 09Apr2021 at 17:00 (at 59-year-old) at single dose for COVID-19 immunization. Patient medical history was reported as none. He had a family history of ulcers but he has never had any ulcers but that could maybe be related to the blood in stool. The patient's concomitant medications were not reported. No additional administered vaccines. The patient previously received the first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, lot number: EN6208), via an unspecified route of administration, administered in right arm on 20Mar2021 at 18:00 (at 59-year-old) at single dose for COVID-19 Immunization, and experienced soreness in the arms. On 10Apr2021 03:00 (reported as 10 hours after receiving the second dose of the vaccine), the patient had a 103 fever, severe chills, every inch of his body ached, headache, shivering uncontrollably and most of this was just for 2 or 3 days. Patient stated then in Apr2021 (reported as a week ago) he had severe low back pain where he could barely walk. Patient stated then last weekend in Apr2021 he had noticed blood in his stool, this started either on last Thursday (29Apr2021) or Friday (30Apr2021). Patient stated and on Tuesday (04May2021) he started getting vertigo, nausea, and passed out. Caller asked was that common side effects or was this an unrelated virus. For event headache, patient stated for 1 day it was a severe headache and then it was a bad headache for 2 or 3 days but he was still experiencing a headache currently. Patient stated the worst part of the headache he has recovered from but he still had a headache and it has gotten much better. For event low back pain, patient stated the back pain got really severe for a week then it got better then came back and right now it was minor but the severe pain was only for about a week. Patient stated that nausea comes and goes. That was another symptom he has lost 12 pounds since getting the second shot. He still felt like he was going to pass out but only passed out that one time. He still had symptoms that he could pass out at any minute. Patient clarified that he went to the emergency room the day after the second dose of the vaccine when his first set of symptoms started. He had also taken ondansetron hydrochloride (ZOFRAN), dimenhydrinate (DRAMAMINE), and paracetamol (TYLENOL). Patient did not visit physician office but he let the physician know. No relevant tests. The outcome of the event severe chills/shivering uncontrollably was recovered on 11Apr2021, events 103 fever and every inch of body ached were recovered on 12Apr2021, event passed out was recovered on 04May2021; outcome of events headache, low back pain, could barely walk, nausea was recovering; outcome of events blood in stool, vertigo, lost 12 pounds since getting the second shot, felt like he was going to pass out was not recovered.