Pain shoots up his leg; hard for him to walk; tenderness in the back of his calf and thigh/the back of his left leg above the knee and back of his calf feels a little weird, tender; Pain in the bottom of his heel; This is a spontaneous report from a contactable consumer or other non health professional (patient). A 77-years-old male patient received BNT162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE; Lot Number: EL3246), via an intramuscular route of administration in the left arm on 28Jan2021 at 9:30 (at the age of 77-years-old) as a single dose for COVID-19 vaccination. Medical history included low iron from unspecified date to ongoing (diagnosed about two years ago). Concomitant medication included iron infusion taking for about 2 years, they cannot seem to straighten it out, states it is uncurable. He had too many red blood cells due to bone marrow, he got on iron infusions, and if his red blood cells gets to high, then they will perform phlebotomy to have them taken out. This was his second year receiving the infusions. He goes in once a week and they test him and sometimes he was able to get the infusion and sometimes he had to wait till the next week. Stated they took a pint of blood out of him about a week and a half ago. He goes every Thursday and his red blood cell count was 15.7. The weight of the patient was 205-206. The patient did not receive any other vaccines within 4 weeks prior to the COVID vaccine. No additional vaccines administered on same date of the Pfizer suspect. On 28Jan2021, the patient had no problem with his arm, not really too many problems at all, except after he got home, the back of his left leg above the knee and back of his calf feels a little weird, tender. Stated he had a crazy feeling on the bottom of his heel, it was killing him, he can barely walk, he did not have this prior to getting the vaccine. He was worried about getting the second dose. Advised to contact hcp. Him and his wife have their second shot scheduled for 28Feb2021. He was told that it can be given up to 4 days ahead or anytime after. He read that Pfizer recommends 21 days between doses The feeling in his heel has stayed the same. States he slept ok. He does had a bad back. When he woke up and tried to put the weight on his left leg he can walk a couple of steps and his heel was killing him. Pain shooted up his leg. It was hard for him to walk. The back of his knee and calf are not really that bad, but he can feel it, he can barely walk. Caller asked have there been any reports of this and how long does it take for the pain to disappear. Caller stated the clinic where they received the vaccine told them the second dose can be scheduled 4 days before 21 days or a week or so after 21 days. Caller also asked if that was going to cause a problem if the second dose is scheduled 28 days after dose 1? they responded saying that "The Pfizer-BioNTech COVID-19 Vaccine vaccination series was 2 doses given 3 weeks apart. This was how Pfizer-BioNTech studied the vaccine. Provided disclaimers that Pfizer was unable to speak outside of the EUA fact sheet and Pfizer was independent of a company guidelines and recommendations. He hoped the heel pain was going to go away and it was something from the vaccine, not something else. The outcome of the event was not recovered.