Did not go back for second dose; she was a little tired; her arm is sore; she got her second shot yesterday after a three month gap; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP) from medical information team for a Pfizer sponsored program. The reporter is the patient. Other Case identifier(s): US-PFIZER INC-202101698117 (Pfizer).  A 51 year-old female patient received bnt162b2 (BNT162B2), administration date 29Nov2021 (Lot number: FG3527, Expiration Date: 31May2021) at the age of 51 years as dose 2, single for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Bnt162b2 (Dose 1, Exp date: 30Sep2021), administration date: 23Aug2021, when the patient was 50 years old, for Covid-19 immunization, reaction(s): "Menstrual Disorder", "Heavy menstrual  bleeding", "Blood pressure increased"; Bnt162b2 (Dose 1, Exp date: 30Sep2021), administration date: 23Aug2021, when the patient was 50 years old, for COVID-19 immunization, reaction(s): "Menstrual cycle prolonged". The following information was reported: INTENTIONAL DOSE OMISSION (non-serious), outcome "unknown", described as "Did not go back for second dose"; INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (non-serious) with onset 29Nov2021, outcome "unknown", described as "she got her second shot yesterday after a three month gap"; FATIGUE (non-serious), outcome "unknown", described as "she was a little tired"; PAIN IN EXTREMITY (non-serious), outcome "unknown", described as "her arm is sore". Relevant laboratory tests and procedures are available in the appropriate section.  Additional Information:  Women have complained about affecting menstrual cycles, isn't that considered kind of serious. They need to stop. Do we see that as alarming. What was the benefit if they were going to experience the same symptoms. Does it say how many, percentage wise. Received first dose in Aug. One month post dose (Sep, middle) longer, heavier menstrual cycle. Oct still waiting. She does not know if she was going to fall into that category. Blood pressure previously in Jun 112, went in 130s. Maybe the stress of the vaccine because she does not normally get vaccines. She always worry about stuff like this. She felt a little pressured. What information was available regarding menstrual changes. Did not go back for second dose. No further demographics provided.  New AE information obtained from the caller. During the call, caller stated that after getting her 2nd dose of the Pfizer-BioNTech Covid19 Vaccine yesterday, she was a little tired and her arm was sore. She thought that the vaccine was not working for her and that her body was not building immunity because the interval of the dose was too long. Description of complaint: This was a follow up report. Pfizer Reference: #. Caller requests no further follow up letters be sent. Pfizer COVID 19 vaccine NDC/LOT/EXP: Unknown, caller says she doesn't have this information handy to provide. Caller says she made a huge error after she went to the vaccine system and read things that were disturbing so she didn't take the second shot, and now she understands how getting the second dose in three weeks prevents getting COVID. She says she got her first dose of Pfizer COVID-19 vaccine on 23Aug2021 and never went back to get her second dose in September. She says she got diagnosed with a light case of COVID on 25Oct2021, and has had no long term COVID. She says after getting COVID she came to the judgement that she made an error not getting her second shot, and she got her second shot yesterday after a three month gap.  Caller states she had her first dose of Comirnaty 23Aug2021 and her second dose was not until 29Nov2021. Caller states she had "a mild case of Covid-19 in OCT2021" between her two doses. Caller states the expiration date for her first dose as noted on her vaccine card was 30Sep2021, while the expiration date for her second dose as noted on her vaccine card was 31May2021. Caller asking if this was correct and if this can be explained. Consult transfer with Customer Service agent, (name), confirmed correct EXP date for LOT FG3527. Caller asking if LOT numbers are all six characters in length. Caller asking how effective her vaccination series was since she did not receive her doses 3 weeks apart. Caller asking if Pfizer was developing a vaccine tailored specifically to Omicron variant.   No follow-up attempts are possible. No further information is expected.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202101211880 Same patient and drug, different dose/event