Concerned she may have cellulitis; Red, swollen, extremely painful appearing an inch away on her arm; Red, swollen, extremely painful appearing an inch away on her arm; Red, swollen, extremely painful appearing an inch away on her arm; had it subcutaneously; Exhausted; hard of hearing; This is a spontaneous report from a contactable consumer, the patient. A 65-years-old female patient received the first dose of bnt162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE; Lot Number: UNKNOWN), via an unspecified route of administration, administered in left arm on an unspecified date as a single dose for covid-19 immunization. Medical history included ongoing scoliosis (occurred 2 years ago), appendicitis perforated, tobacco user (she smoked 3-5 packs a day for 48 and a half years; she quit on 31Jul2020). The patient's concomitant medications were not reported. The patient got the vaccine on her left arm which was her non-dominant and weaker arm and was afraid that she was not able to get the vaccine intramuscularly as prescribed, instead she believed she had it subcutaneously. The patient was hard of hearing, uses hearing aids. Caller states that the needle needs to go into the middle of the deltoid when you receive the vaccine. She asked for it to be put on her left side. States the left is her weaker side due to her scoliosis. She didn't feel the vaccine and wasn't sure where the nurse put it at first. She mentioned that a friend went with her to help translate because the caller cannot hear people when they speak through the masks. She reported scoliosis has hunched her shoulders over the years. The nurse giving the vaccine found an ideal spot to put it per the caller. The reaction she has had isn't near where the vaccine was injected. She was worried it did not go in perpendicular. She reported that four hours after the vaccine she wasn't using her arm; she touched it though and shrieked. It was near her underarm. It was horribly painful. She could not lift her arm over her shoulder. She did some exercises and took a warm shower and that helped it stop. She went to bed early and was exhausted, not from the vaccine though; just because she was worried about things. The next day her entire left side of her arm, an inch from the deltoid towards the front, was red, swollen, and extremely painful appearing an inch away on her arm (description by the caller: red as a fire engine track, hot and swollen, extremely swollen, red agonizing pain almost felt like muscular pain). The area where the needle went was not swollen and red. Area where she located the redness and swelling was around 4 inches away from the injection site. Additional description she provided was if she had her biceps pop up- draw line from mid bicep to your shoulder- where the redness, close to underarm. She thinks the nurse gave her the vaccine subcutaneously. She realized it didn't hurt where the needle went in. She worried it was cellulitis. Also worried that she didn't have any protection from the vaccine. She is worried about what happens if you get a vaccine subcutaneously instead of in the muscle. The redness was pink now and it had calmed down. She doesn't know what to do. Caller denies any medications, labs, testing, or treatments relevant to events. States she would not have been concerned or contacted Pfizer if any part of the redness or swelling included the area where the needle was actually inserted. This past Saturday was the worst for the pain. She was most scared that she isn't vaccinated. Caller states she doesn't want to get sick because a nurse made a mistake. Caller states that she will call back to provide the Lot number for her vaccination. The patient main concern is about the safety and efficacy of the PFIZER-BIONTECH COVID-19 VACCINE if it was given on the subcutaneous site instead of the recommended (IM). Also, wanted to know if there is any problem if the vaccine is running around her bloodstream. And also asking what should she do about this. The patient was on hold with the hospital that administered the vaccine, and they told her to go to the ER. But caller refused to do so because she did not see the need to. Also, had to warm-transfer to CDC as caller is very persistent in insisting that the HCPs in the hospital where she got the vaccine is not able to help her and may not admit that the vaccine was given to them subcutaneous instead of intramuscular. Outcome of the event- red, swollen, extremely painful appearing an inch away on her arm was not resolved, while that for other events was unknown. Information on the lot/batch number has been requested.