strange, frightening sensations in his lower spine.; strange, frightening sensations in his lower spine.\experienced strange behavior in lower spine probably L4-L5; This is a spontaneous report from a contactable consumer or other non-HCP (patient himself) via Medical Information Team. An 84-year-old male patient received BNT162b2 (PFIZER BIONTECH COVID-19 mRNA VACCINE, Solution for injection, Lot number- FA6780) via an unspecified route of administration in left arm on 22Jul2021 at a dose of 0.3 ml as dose 1, single (at the age of 84-years-old) for COVID-19 immunization. The NDC number of Pfizer COVID-19 vaccine was reported as 59267-1000-02. Patient medical history included surgery (surgery to lower spine L4-L5) from an unknown date and unknown if ongoing (had it 10-12 years ago) deep vein thrombosis from an unknown date and unknown if ongoing (had it 10-15 years ago). The concomitant medications included warfarin at a dose and frequency of 4mg tablet orally every day taken for deep vein thrombosis from an unspecified start date which he started taken around 10-15 years ago and ongoing. The patient experienced strange, frightening sensations in his lower spine\experienced strange behavior in lower spine probably l4-l5, on an unspecified date in 2021. An elderly male patient of unspecified age experienced strange sensations in his lower spine 15 days after his first dose of the Pfizer BioNTech Covid-19 Vaccine. Patient stated his first dose of the vaccine was on 22Jul2021. He stated that 15 days after vaccination he began experiencing strange, frightening sensations in his lower spine. He stated he had back surgery years ago, and his surgeon cleaned it out and since then he had felt terrific. Stated that he could have gotten the second shot last week but that he is due 11Aug2021 or next week. He wanted to know if it attacks a certain place and goes away will it come back in the same place for the second shot. He stated this feeling was scary. He stated he swims three times a week and never has had a reaction from that. He stated his primary doctor recommended he get the Covid-19 Vaccine. He stated that the strange sensations have been getting better. He reported improvement within the next 1 to 2 days and stated that now it was practically not bothering him at all. He almost reached out to his spinal surgeon from years ago when these sensations began. He was concerned that if he gets the second dose of the vaccine, the vaccine will attack the same part of his spine again. He was asking if this was possible and if this could be an expected side effect from the vaccine. First, COVID-19 mRNA vaccines are given in the upper arm muscle. Once the instructions (mRNA) are inside the immune cells, the cells use them to make the protein piece. After the protein piece is made, the cell breaks down the instructions and gets rid of them. Next, the cell displays the protein piece on its surface. Our immune systems recognize that the protein doesn't belong there and begin building an immune response and making antibodies, like what happens in natural infection against COVID-19. Patient did not receive treatment for the adverse events. The outcome of the events was unknown.