After I went to bed, I started developing chills; I spent all day, Saturday in bed. I was just that tired.; a low grade fever of 99.3; Achiness; generalized muscle pain; nausea; general unwell feeling; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 65-year-old female patient received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 21Oct2022 as dose number unknown (booster), single (Lot number: GJ6665, Expiration Date: 30Jun2023) at the age of 65 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "Anxiety" (unspecified if ongoing), notes: Comments: Anxiety; "Stress" (unspecified if ongoing), notes: Comments: Stress; "High Blood Pressure" (unspecified if ongoing), notes: Comments: High Blood Pressure; "Hypothyroidism" (unspecified if ongoing), notes: Indication for use in the case: Hypothyroidism; "Cholesterol" (unspecified if ongoing), notes: Indication for use in the case: Cholesterol. Concomitant medication(s) included: LEVOTHYROXINE taken for hypothyroidism; SYNTHROID taken for hypothyroidism; PRAVASTATIN taken for blood cholesterol; METOPROLOL SUCCINATE taken for hypertension; ALENDRONATE SODIUM taken for bone disorder. Vaccination history included: Covid-19 vaccine (primary immunization series completed, unknown manufacturer), for COVID-19 Immunization. The following information was reported: PAIN (non-serious) with onset 22Oct2022, outcome "unknown", described as "Achiness"; CHILLS (non-serious) with onset 22Oct2022, outcome "not recovered", described as "After I went to bed, I started developing chills"; FATIGUE (non-serious) with onset 22Oct2022, outcome "unknown", described as "I spent all day, Saturday in bed. I was just that tired."; PYREXIA (non-serious) with onset 22Oct2022, outcome "recovered", described as "a low grade fever of 99.3"; MALAISE (non-serious) with onset 22Oct2022, outcome "unknown", described as "general unwell feeling"; MYALGIA (non-serious) with onset 22Oct2022, outcome "unknown", described as "generalized muscle pain"; NAUSEA (non-serious) with onset 22Oct2022, outcome "unknown". Relevant laboratory tests and procedures are available in the appropriate section.  Additional Information: It was reported that she just wanted to report some very mild side effects, she received Covid Bivalent Booster shot (Clarified as: Pfizer Covid-19 Vaccine Bivalent). She received it on Friday in the early afternoon and she was just fine all Friday, came back home, did everything. But after she went to bed, she started developing chills, a low grade fever of 99.3, achiness, generalized muscle pain, nausea, no vomiting, and just a general unwell feeling. She spent all day, Saturday in bed. She was just that tired. She would get up, attend to her cats and go back to bed. On Sunday, She was feeling a little bit better but she took the precaution of calling in for work tomorrow because She was still not feeling a 100 percent, She still felt chills, She did not check her temperature but she said probably. She do not know, if she was normal yet or not? But they are all very mild, nothing that she would be terribly concerned about but she though. Treatment: Consumer reported that No. she stayed home and in bed. She was doing the same except she was actually managing to get out of bed and just maintaining good fluids, drinking some orange juice, lots of water, keeping herself warm since she was still experiencing the chills though she did check her temperature, she do not have a fever at that point. But still have the chills. She had the temperature up to 78 Degrees in her house but she was still feeling cold. Other medical conditions and concomitant medications: Consumer reported that she took other medications and yes one of them is for High Blood Pressure. Her prescription medications she took Synthroid or Levothyroxine 50mcg for Hypothyroidism(not clarified hence, captured both), Pravastatin 40mg, that's for Cholesterol, Buspar Hydrocloride' 5mg (further not clarified). One Tablet twice a day that's for Anxiety and stress, Metoprolol Succinate 25 mg, One Tablet, Twice a day for High Blood Pressure and Alendronate Sodium otherwise known as Fosamax 70 milligrams, getting her bones back to their good health.  No follow-up attempts are possible. No further information is expected.