menstruation prolonged (over 17 days of bleeding); hormonal imbalance; this is a spontaneous report received from a contactable consumer from the ra-web. regulatory number: gr-greof-202200927. a 26 year-old female patient received bnt162b2 (comirnaty), administration date 01feb2022 (batch/lot number: unknown) at the age of 26 years as dose 1, single for covid-19 immunisation. the patient's relevant medical history and concomitant medications were not reported. the following information was reported: heavy menstrual bleeding (medically significant) with onset 01feb2022, outcome "not recovered", described as "menstruation prolonged (over 17 days of bleeding)"; hormone level abnormal (medically significant) with onset 01feb2022, outcome "not recovered", described as "hormonal imbalance". no history of allergies or hormonal disorder. no follow-up attempts are possible; information about lot/batch number cannot be obtained. no further information is expected