knocked her out for 1 day; she could not eat, sleep and drink; She lost 13 pounds; had pain in her arm and leg, her body ached in every bone, her toes and fingers were all crunched up; chest pain; Initial information received on 19-Jan-2021 regarding an unsolicited valid serious case was received from a consumer/non-health care professional via Agency (Reference number-00435692) and transmitted to Sanofi on 19-Jan-2021.  This case involves a female-patient of unknown age who could not eat, sleep and drink (loss of personal independence in daily activities), knocked out for 1 day (loss of consciousness), lost 13 pounds (weight decreased), pain in her arm and leg, her body ached in every bone, her toes and fingers were all crunched up (pain) and chest pain, while she received vaccine INFLUENZA QUADRIVAL A-B HIGH DOSE HV VACCINE [FLUZONE HIGH-DOSE QUADRIVALENT].  The patient's medical history, past medical treatment(s), concomitant therapy, vaccination(s) and family history were not provided.  On an unknown date, the patient received a dose of suspect INFLUENZA QUADRIVAL A-B HIGH DOSE HV VACCINE (lot number and expiry date not reported) via an unknown route in unknown administration site for prophylactic vaccination.  On an unknown date, the patient was knocked out for 1 day (loss of consciousness) (Unknown latency) following the administration of INFLUENZA QUADRIVAL A-B HIGH DOSE HV VACCINE. This event was assessed as medically significant.  On an unknown date, the patient could not eat, sleep and drink (loss of personal independence in daily activities) and lost 13 pounds (weight decreased), pain in her arm and leg, her body ached in every bone, her toes and fingers were all crunched up (pain) and chest pain (Unknown latency) following the administration of INFLUENZA QUADRIVAL A-B HIGH DOSE HV VACCINE.  It was reported that this year patient went to get her flu shot again, but requested that it was not the Fluzone High Dose Quadrivalent again. She was informed this year was different. She said as long as the pain does not last longer than 1 day. This time it lasted 15 days and the suffering was so bad. She also called her HCP (health care professional) to inform him of the chest pain earlier and he told her to go to ER (emergency room). She told the HCP that she felt fine and it was due to the Fluzone High Dose Quadrivalent Vaccine which had affected her muscles including her heart and was finally not causing anymore side effects after 13 days.  Details of laboratory data were not reported.   The patient took 3 aspirin and 1 pain pill. The patient then went to sleep. Three hours later, the patient woke up and felt fine.   On an unknown date, outcome for weight loss was unknown and she had recovered from rest other events.  Reporter assessed the causal relationship with suspect vaccine as not reported via global introspection.  It was also reported that the patient was on her way to her HCP and could not provide any further information.  Information on the batch number was requested.; Sender's Comments: This case involves a female-patient of unknown age who experienced loss of personal independence in daily activities, loss of consciousness, weight decreased, pain and chest pain after vaccination with FLUZONE HIGH-DOSE QUADRIVALENT. The time to onset was unknown. Further information regarding medical history, concurrent condition during vaccination, previous vaccination and tolerance, allergic history, laboratory investigations excluding alternative etiologies for the reported event are needed to fully assess this case. Based upon the reported information, the role of the suspect vaccine cannot be assessed.