chills; 102 degree fever. She then had a low grade fever for the next few days; not feeling great; This is a spontaneous report from a contactable consumer (caregiver). A 14-years-old female (daughter) patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Batch/Lot number was not reported), via an unspecified route of administration on 23Aug2021 as dose 1, single for COVID-19 immunisation. Medical history included Covid-19 on Dec2020. The patient's concomitant medications were not reported. It was reported that the consumer was a caregiver for her 14 year old daughter who received the first dose of BNT162B2 on 23Aug2021. The next day on 24Aug2021, she had a 102 degree Fahrenheit fever and was not feeling great. She then had a low grade fever for the next few days. On 28Aug2021 (Saturday) she was feeling a little bit better. On Sunday (29Aug2021) she began experiencing chills, her fever rose, and she was given ibuprofen. On Monday (30Aug2021) morning she woke up with a fever above 102 degree Fahrenheit, and she brought her to the doctor. By Monday night she had a 103 degree Fahrenheit fever after 6 doses of ibuprofen during the day, going up and down. She had a little and then began alternating Tylenol and ibuprofen every 3 hours. Yesterday (31Aug2021) she was feeling a little better. She actually did have Covid-19 in Dec2020, but it was mild; It was suggested that she get an antibody test prior to vaccination so we did that the morning before she got the vaccine on 23Aug2021, but we went ahead and she got the vaccine anyway after that. Monday on 23Aug2021, when she went to the doctor the doctor said she was positive for antibodies. The doctor wants her to wait three months before she gets the second dose of BNT162B2 and then test her for antibodies. The caregiver was asking if this pattern of fever/malaise was consistent with side effects experienced by most after BNT162B2 vaccination. The caregiver was asking if her daughter's previous Covid-19 could have caused her side effects to be worse post-vaccination with BNT162B2. No seriousness was provided. Treatment received included ibuprofen and Tylenol for all events. The patient visited physician office for all events. The outcome of the events was recovering.  The Centers for Disease Control and Prevention (CDC) provides information regarding "Possible Side Effects After Getting a COVID-19 Vaccine". COVID-19 vaccination will help protect you from getting COVID-19. You may have some side effects, which are normal signs that your body is building protection. These side effects may affect your ability to do daily activities, but they should go away in a few days. Some people have no side effects. Serious side effects that could cause a long-term health problem are extremely unlikely following any vaccination, including COVID-19 vaccination. Vaccine monitoring has historically shown that side effects generally happen within six weeks of receiving a vaccine dose. For this reason, the FDA required each of the authorized COVID-19 vaccines to be studied for at least two months (eight weeks) after the final dose. The FDA-approved COMIRNATY (COVID-19 Vaccine, mRNA) and the FDA authorized Pfizer-BioNTech COVID-19 Vaccine under Emergency Use Authorization (EUA) have the same formulation and can be used interchangeably to provide the COVID-19 vaccination series. There was a remote chance that the vaccine could cause a severe allergic reaction. A severe allergic reaction would usually occur within a few minutes to one hour after getting a dose of the vaccine. For this reason, your vaccination provider may ask you to stay at the place where you received your vaccine for monitoring after vaccination. Signs of a severe allergic reaction can include: Difficulty breathing, swelling of your face and throat, a fast heartbeat, a bad rash all over your body, dizziness and weakness, myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining outside the heart) have occurred in some people who have received COMIRNATY (COVID-19 Vaccine, mRNA) or the Pfizer BioNTech COVID-19 Vaccine. In most of these people, symptoms began within a few days following receipt of the second dose of vaccine. the chance of having this occur is very low. you should seek medical attention right away if you have any of the following symptoms after receiving the vaccine: chest pain, shortness of breath, feelings of having a fast-beating, fluttering, or pounding heart, side effects that you may experience throughout the rest of your body; (systemic side effects) including fever and chills were observed with the first 1 to 2 days after vaccination and resolved shortly thereafter.  This follow-up is being submitted to notify that the lot/batch number is not available despite the follow-up attempts made. Follow-up attempts have been completed and no further information is expected.