had an anaphylactic reaction to the DTaP shot because it had traces of dairy in it; Initial information received on 22-Dec-2021 regarding an unsolicited valid serious case received via a consumer/non-hcp.  This case involves a 20 years old female patient who had an anaphylactic reaction to the dtap shot because it had traces of dairy in it while receiving vaccine DIPHTHERIA, TETANUS AND ACELLULAR PERTUSSIS VACCINE.   The patient's past medical history, medical treatment(s), and family history were not provided. The patient had Anaphylactic reaction to previous vaccines.  Concomitant medications included Tozinameran (Comirnaty) for Immunisation.  On an unknown date, the patient received a dose  dose of suspect Diphtheria, tetanus and acellular pertussis vaccine produced by unknown manufacturer (formulation, stremgth, dose and lot number not reported) via unknown route in unknown administration site for immunisation.  On an unknown date the patient developed a serious had an anaphylactic reaction to the dtap shot because it had traces of dairy in it (anaphylactic reaction) (unknown latency) following the administration of Diphtheria and tetanus and acellular pertussis vaccine. This event was assessed as medically significant.  Reporter was calling in regards to the COVID-19 vaccine. Her daughter got the first dose and the second dose and she was fine with both of those doses. The caller's daughter is scheduled to get her booster dose tomorrow. The caller explains she called Pfizer yesterday and started this process. She was looking to see if there was any different in ingredients and inactive ingredients from her daughter's Lots she had in June to the booster dose her daughter is scheduled to receive tomorrow. The caller states she sees on the website the inactive ingredients are based on the purple cap and gray cap, but only the purple is available. The gray cap is not released yet or something. The caller states her question today is based on her daughter's anaphylaxis to dairy. She was looking to see if there was any different in ingredients and inactive ingredients from her daughter's Lots she had in June to the booster dose her daughter is scheduled to receive tomorrow. The caller states she sees on the website the inactive ingredients are based on the purple cap and gray cap, but only the purple is available. The gray cap is not released yet or something. The caller states her question today is based on her daughter's anaphylaxis to dairy. She looked on Pfizer's allergen page and put in dairy and basically it says dairy products are used in the manufacturing process but are not expected to be in the final product. She always thought dairy wasn't used in the manufacturing process, therefore there wouldn't be any chance of dairy. The caller called the vaccine facility where her daughter will be getting her vaccine at to determine the Lot number because the caller wanted to find out if the Lot number of the booster dose was manufactured at the same place as the first two Lot numbers. Since her daughter did not have any reaction to the first two doses, she would feel better knowing if the Lot number for her booster dose was manufactured at the same place with the same quality control and cross-contamination process, things like that.  Action taken with Diphtheria, tetanus and acellular pertussis vaccine was not applicable.  It was not reported if the patient received a corrective treatment for the event.  At time of reporting, the outcome was Unknown for the event had an anaphylactic reaction to the dtap shot because it had traces of dairy in it.; Sender's Comments: Sanofi Company Comment on 22-Dec-2021: This case involves 20 years old female patient who experienced Anaphylactic reaction. The time to onset was unknown. Further information regarding medical history, concurrent condition during vaccination, previous vaccination, concomitant medication and tolerance, allergic history, laboratory investigations excluding alternative etiologies for the reported event are needed to fully assess this case. Based on the reported information, the role of the individual suspect vaccine cannot be assessed.