severe anaphylactic reaction to the influenza vaccine; Initial information received on 25-Jun-2021 regarding an unsolicited valid serious case received from a physician.  This case involves an unknown age female patient who experienced severe anaphylactic reaction (anaphylactic reaction), while she received INFLUENZA VACCINE and TOZINAMERAN [PFIZER BIONTECH Coronavirus disease (COVID-19) VACCINE].  The patient's medical treatments, vaccinations, concomitant medications and family history were not provided.  At the time of the event, the patient had ongoing medical history of allergy to iodine and penicillin (Drug hypersensitivity).   On an unknown date, the patient received a dose of suspect INFLUENZA VACCINE produced by unknown manufacturer and a dose of suspect PFIZER BIONTECH COVID-19 VACCINE not produced by Sanofi Pasteur (batch number and expiry date not reported) via an unknown route in unknown administration site for prophylactic vaccination respectively.  On an unknown date, the patient experienced a serious severe anaphylactic reaction to the influenza vaccine (anaphylactic reaction) (unknown latency) following the administration of INFLUENZA VACCINE and PFIZER BIONTECH COVID-19 VACCINE. This event was assessed as medically significant.  It is unknown if the patient experienced any additional symptoms/ event. It is unknown if there were lab data/ results available.  Caller states that he is an Infectious Disease physician who is calling today in regards to the Pfizer (COVID-19) vaccine and his wife. He goes on to states that is wife has an allergy to iodine and penicillin and has previously had a severe anaphylactic reaction to the influenza vaccine. He states that since she has had these allergies and reactions in the past he is looking into some research to see if he would recommend his wife to get the vaccine. He is asking for any information regarding the administration of the vaccine in 4 smaller doses rather than the current two dose series that is recommended. He reports that he understands the information may be limited and just wanted to check and see if there had been in studies done in this case. Adverse Event recognized after the call of wife having reaction to flu vaccine in the past. Electronic-transmitting information. Response: Spoke from attached documents regarding the Health Care Professional (HCP) inquiry. Advised that there is limited information on this topic but relayed that there are currently ongoing trials for pediatric patients that are being studies with a variety of different dosage amounts that may be helpful for him. Disclaimers provided. Reporter was very thankful and happy to receive any information. Sharing information via email per HCP request. Request Name: PFIZER-BIONTECH (COVID-19) VACCINE Question: Pfizer has done a wonderful job being able to develop and supply a safe and very much effective vaccine in such a short amount of time based on previous vaccine and timelines. This has been so important and helpful for our country and I just want to thank Pfizer. Age group actually not provided. It is unknown if patient's physician provided consent to be contacted.   It was not reported if the patient received a corrective treatment for the event.  At time of reporting, the outcome of event was unknown.  Information on the batch number was requested for this case.; Sender's Comments: This case concerns an unknown age female patient who experienced severe anaphylactic reaction after vaccination with INFLUENZA VACCINE produced by unknown manufacturer and PFIZER BIONTECH Coronavirus disease (COVID-19) VACCINE not produced by Sanofi Pasteur. The time to onset is unknown. The patient has a known allergy to iodine and penicillin, and other medical history and lab tests was not reported. Based upon the reported information, the role of the suspect vaccines cannot be individually assessed.