noticed diminished hearing in the right ear/couldn't hear a tick at all; he felt fullness in his right ear; sore left arm where he got injection; This is a spontaneous report from a contactable physician (patient). A 71-year-old male patient received first dose of bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE; lot number: EM9809, expiry date: unknown), via an unspecified route of administration on 10Feb2021 12:30 (at 71-year-old) at single dose (left arm) for COVID-19 immunization. Medical history included hypertension (mild hypertension and it is well controlled, it was diagnosed 5-6 years ago), hyperlipidemia (mild hyperlipidemia and it is well controlled, it was diagnosed 5-10 years ago). He stated in Aug, he tested positive for antibodies through Lab and was still positive a month later. He wondered how that might effect the decision of if he should get the second dose, if he is potentially immune. He had no symptoms but tested negative with PCR test. His girlfriend who he lives with tested negative for antibodies. Height was reported as 6 feet to 6 feet one inch tall. Weight was reported as 176-178lbs, he thought he may have gained a few pounds. There were no concomitant medications. The caller had the first dose of the vaccine 10Feb2021 12:30. 5 days later he felt fullness in his right ear (Feb2021) and noticed diminished hearing in the right ear (Feb2021), maybe 20-30% less. He was comparing how much he could hear the ticking of his watch in his left and right ear and couldn't hear a tick at all. He went to an ENT and they found that it was reduced in the right ear secondary to a nerve problem and wasn't secondary to anything else. The doctor read online on an ENT site, a couple of people had acute bouts of decreased hearing. They were treated with steroids and resolved. His provider prescribed him with a high dose of steroids, 70 mg. He was going to take it after dinner but all of the sudden he could hear the ticking better. He held off on taking the steroid and the next morning his hearing was fine. He went back and they retested and it was back to normal. He had taken Naprosyn and is not sure if that played a part in improving things. It resolved not even 24 hours after the initial symptoms. It resolved on its own. He asked, is this a side effect that has been reported? Are there any cases of this happening in one ear rather than 2? Could it be a contraindication getting the second dose? His doctor is researching it and he is supposed to call early next week about this. He asked how many people were in the clinical trials that the side effect data is based on. The caller stated he heard someone report that he doesn't believe that people getting the vaccine necessarily need both doses of the vaccine. They are finding after a week after the first dose they have relative immunity and might not need the second dose. The caller asked how effective this vaccine might be on new variants, how effective just one dose of the vaccine is, if Pfizer is looking into mixing the vaccines- whether it will be something that can be interchanged with other Covid-19 vaccines, asked where he could find updates on medical information about  this in the future. The caller stated he wanted to thank Pfizer for developing the vaccine as quickly as they did. Retired psychiatrist calling about Pfizer COVID-19 vaccine who says he got his first dose on 10Feb in (State name), and had a sore left arm where he got the injection (Feb2021) then 5 days later had fullness in his right ear with his hearing diminished. He says he called his otolaryngologist because he had had a hearing test a few months ago, and was tested again now and there was a moderate decrease of hearing in his right ear. He says he would like to know if this could be a possible side effect, since he has read of reports and his otolaryngologist knew of two reports where people did report hearing loss. He says that he was treated acutely with steroids at high dose of 70mg for which he filled the script, then called his internist who was ambivalent with him taking a high dose. Caller says then within a few hours, his hearing was better, and by the next morning it was normal, and he went back to the ENT and his hearing was the same as it was a few months ago. He says he did not take the steroid he was prescribed, the Prednisone, he took Naproxen, and since it may have been a nerve problem with hearing diminished related to auditory nerve, it seemed to get better in a number of hours. He says he has reported this already to VAERS. Caller says his right ear is better now, it got better within a a few hours after he saw his doctor, then it was completely better by the next morning. He says that after they tested his hearing due to the fullness in his ear and hearing being diminished it got  better on its own. He says on the next hearing test his hearing was exactly back to normal. He says he did take Naproxen once or twice during that time period, 20 or less hour period, more like 12 hours, one 220mg tablet each time, he doesn't know whether that contributed to helping. Naproxen (EXP Jan2022, LOT: ODRO445). He says that the reason he is calling is to see whether Pfizer has had similar reports. He says that he saw on a website that 12 people were reporting deafness or blindness, but it seemed to be an (name), so he took it with a grain of salt. He says he would like to know whether people have been reporting with issues for hearing, unilaterally or bilaterally, or what results have been with some people. Caller says unfortunately the website he mentioned was obviously anti vaccine and claimed to be with the (name) or version of the CDC and said that they were reporting they had 12 people reporting deafness and blindness from COVID vaccine and made it sound like the most dangerous vaccine in the world, but it was a conspiracy website that claimed it was with the equivalent of CDC. Caller does not have website addresses to provide or details about reports on that site.  Caller says he looked at the (name) and it said nothing about this kind of possible side effect. He says he doesn't know if his could be related to getting the vaccine, or if he should still get a second dose of the vaccine. The outcome of the event "noticed diminished hearing in the right ear/couldn't hear a tick at all" and "he felt fullness in his right ear" was recovered in Feb2021, while for other event was unknown.; Sender's Comments: Based on available information the reported unilateral  deafness was unlikely related to bnt162b2.  This was  an intercurrent medical condition.  Case will be reassessed if additional information is received.    The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate.