White blood count went down from 16,600 to 11,400; on the 04Feb2021 in the ER, my hemoglobin was 14.6 and on 10Mar2021 it was 11.6; Achy; Fatigue; Headache; Higher HR; Difficulty breathing; This is a spontaneous report from a contactable consumer or other non hcp.   A 72-years-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, solution for injection, Batch/Lot Number: EN9581), via intramuscular route, administered in Arm Left on 17Feb2021 16:30 (at the age of 72-year-old) as dose 2, single for covid-19 immunisation. Medical history included hypertension (blood pressure high) from an unknown date and unknown if ongoing, pacemaker from an unknown date, Second degree heart block from 27May2021; ongoing (permanent dual lead pacemaker 27May2020); stage 1 breast cancer from 29Jun2021; ongoing (bilateral mastectomies reconstruction 26Aug2015); post menopausal vaginal bleeding benign from Mar2020 and ongoing (bilateral oophorectomy hysterectomy 18Mar2020). Concomitant medications included lisinopril oral taken for hypertension from Jun2015 and ongoing; glucosamine oral taken for an unspecified indication from an unspecified start date and ongoing; docusate sodium (STOOL SOFTENER) taken oral for an unspecified indication from an unspecified start date and ongoing; magnesium taken oral for an unspecified indication from an unspecified start date and ongoing. The patient previously took BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, solution for injection, Batch/Lot Number: EL 9264), via an intramuscular route, administered in arm left on 27Jan2021 at 16:30 (at the age of 72-years-old) as dose 1, single for covid-19 immunization and experienced tachycardia, pericarditis, pneumonia, fatigue, chest pain, dyspnoea, headache, pain, heart rate increased, back pain, illness, arthralgia. On 10Mar2021, the patient experienced white blood count went down from 16,600 to 11,400, her haemoglobin was 14.6 and on 10mar2021 it was 11.6. On an unknown date in 2021, patient experienced achy, fatigue, headache, heart rate increased, and difficulty breathing. The patient underwent lab tests and procedures which included computerised tomogram: abnormal on 04Feb2021 Bilateral infiltrates and right pleural effusion, full blood count: unknown on 04Feb2021 HGB-14.6, WBC-15,600 HOB dropped due to inflammation, haemoglobin: 14.6 on 04Feb2021, myocardial necrosis marker: normal on 04Feb2021 a friction rub was heard done before cardioversion, sedation: 48 on 10Mar2021 due to inflammation (pericarditis), electrocardiogram: atrial tachycardia on 14Feb2021 Abnormal-with pacemaker artifact, chest x-ray: normal on 23Feb2021, covid-19: negative on 05Mar2021, haemoglobin: 11.6 on 10Mar2021, full blood count: unknown on 10Mar2021 HGB-11.6, WBC-11,400 HOB dropped due to inflammation, echocardiogram: normal on 24Mar2021, white blood cell count: 16,600. On 24Mar, she had a cardioversion to try to deal with the tachycardia and in order to do that she had to take Eliquis which is a blood thinner so that was the other prescription she had, she was no longer on that one." Therapeutic measures taken as a result of events included prednisone, and Flecainide. Patient did not take the prednisone until 11Mar2021. The outcome of the events was unknown.  No further information was provided.