2nd dose of Covid-19 vaccine scheduled for greater than 21 days after 1st dose; Dull headache/headache comes and goes; Once or twice per day he can feel something that feels like someone is putting their fingers in the back of his head; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 60 year-old male patient received bnt162b2 (Formulation: Solution for injection), administered in arm left, administration date Apr2021 (Batch/Lot number: unknown) at the age of 60 years as dose 1, single for covid-19 immunisation. Relevant medical history included: "Hypertension", start date: 1990 (ongoing), notes: Verbatim: Blood pressure high; "Blood potassium decreased" (ongoing), notes: Caller reported that his potassium was low a couple of years ago. Caller reported that his potassium levels have been fine here lately.; "Diabetes mellitus" (ongoing), notes: Caller reported that he was diagnosed with diabetes 2 or 3 years ago.; "Arthritis" (ongoing), notes: Caller reported that he was diagnosed with arthritis within the last 5 years. Concomitant medication(s) included: LOSARTAN taken for hypertension, start date: 1990 (ongoing); HYDROCHLOROTHIAZIDE taken for hypertension, start date: 1990 (ongoing); ATENOLOL taken for hypertension, start date: 1990 (ongoing); METFORMIN taken for diabetes mellitus (ongoing); POTASSIUM taken for blood potassium decreased (ongoing); MELOXICAM taken for arthritis (ongoing). Past drug history included: Niacin, reaction(s): "Hot flushes", notes: he was previously taking Niacin as his Niacin was low, too. Caller reported that he was getting hot flushes real bad with the Niacin and passed out one day. Caller reported that he stopped taking the Niacin 5-10 years ago. The following information was reported: HEADACHE (non-serious) with onset Apr2021, outcome "not recovered", described as "Dull headache/headache comes and goes"; HEAD DISCOMFORT (non-serious) with onset Apr2021, outcome "not recovered", described as "Once or twice per day he can feel something that feels like someone is putting their fingers in the back of his head"; CIRCUMSTANCE OR INFORMATION CAPABLE OF LEADING TO MEDICATION ERROR (non-serious), outcome "unknown", described as "2nd dose of Covid-19 vaccine scheduled for greater than 21 days after 1st dose".  Additional Information for Concomitant Products Losartan: Caller reported that he used to take a combination pill of Losartan and Hydrochlorothiazide.  Caller reported that a year or two ago, he began taking the 2 medications separately. Dates for Concomitant Products, Hydrochlorothiazide: (Start: 1990 Stop: Ongoing);  Caller reported that he began taking Metformin 2 years ago. Additional Information for Concomitant Products Meloxicam: Caller reported that he began taking Meloxicam within the last 5 years or so. Caller reported that his hands had been real tight and have been a lot better since starting Meloxicam. Additional Information for Other Conditions: Caller reported that his potassium was low a couple of years ago.  Caller reported that his potassium levels have been fine here lately. Caller reported that he was diagnosed with diabetes 2 or 3 years ago. Caller reported that he was diagnosed with arthritis within the last 5 years. Additional Context: Caller is a consumer calling in regards to the Pfizer Covid-19 vaccine. Caller reported that he has been experiencing a dull headache. Caller reported that his headache began about a week after receiving the first dose of the Covid-19 vaccine. Dull headache: Caller reported that the headache is not real bad, it's more annoying. Caller reported that the headache is at the back of his head and its never too bad, but sometimes if he shakes or moves his head, it feels a little bit like the headache is there. Caller stated that he wasn't going to report the dull headache to Pfizer because the headache isn't really a real issue.  Caller reported that the headache is just kind of there every now and then. Caller reported that he feels the headache once or so every day. Caller reported that he doesn't have his vaccination card with him.  Caller reported that he got his first dose of the Covid-19 vaccine on 22Apr2021 or 29Apr2021. Caller reported that he is due to get the other dose of the Covid-19 vaccine on 25May2021. Caller reported that he got the first dose of the Covid-19 vaccine within the last 2 weeks of Apr2021.  Caller reported that he didn't get the headache until a week after the Covid-19 vaccine. Caller reported that he just keeps getting the headache and it's there every day. Caller reported that the headache is nothing real painful, it is just kind of annoying.  Caller reported that the headache doesn't really hurt but he can just tell it's there. Caller unable to provide product details for Covid-19 vaccine as he does not have his vaccination paperwork with him. Indication: Caller reported that his girlfriend had just gotten the Covid-19 vaccine and a couple of other people he knows had as well.  Caller reported that he works for (withheld).  Caller reported that he thought that his employer was going to give the employees the Covid-19 vaccine. Caller reported that he went to get the Covid-19 vaccine elsewhere when he had the opportunity. Potassium: Caller reported that he is getting off of the Potassium and that he has weaned down to 3 tablets daily from 6 tablets daily with consent of his doctor. Caller reported that he is dropping his potassium dosage little by little. Caller reported that he was previously taking Niacin as his Niacin was low, too. Caller reported that he was getting hot flushes real bad with the Niacin and passed out one day.  Caller reported that he stopped taking the Niacin 5-10 years ago.  Caller unable to provide product details for the Niacin. Caller reported that he debated calling Pfizer to make a report. Caller reported that he was debating if his headache was really a thing or not. Caller reported that since the last week or so that hes had the headache, he thinks it's only  been once or twice that he has taken Tylenol or something like that for his headache just to see if it would go away and it did. Caller reported that his head is not really hurting and the headache is not really a pain.  Caller reported that it is hard to describe, but once or twice per day he can feel something that feels like someone is putting their fingers in the back of his head.  Caller reported that it is not real hard, but it just kind of there, then he doesn't feel it anymore. Caller reported that he was not feeling the headache at time of call on 04May2021, but that he felt it earlier that morning. Caller reported that the headache comes and goes, or maybe increases to where the caller knows it's there and then it's gone again.   No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.