I was falling down; Fast heartbeat (heart rate went up to 118 beats per minute); It was hard for the patient to talk; Kinda dizzy; Weakness/ weak state; Feel weakness in legs / my legs were so weak/the patient could not stand up.; Difficulty breathing; Oxygen levels ''went down to 88%''; Got scabies; This spontaneous case was received on 07-Oct-2022 from other non-healthcare professional (consumer) via Communications and concerned a female patient of an unspecified age.  The patient's medical history inluded past procedure lung volume reduction surgery. The patient's concomitant medications were not reported.  On 12-Sep-2021, the patient was vaccinated with Fluad Quadrivalent (influenza vaccine inact sag 4v; dose: 0.5 ml; route of administration and anatomical location: not reported) for active immunization of persons 65 years of age or older against influenza. The batch number reported was 312832 and expiry date reported was 11-May-2022.  On an unspecified date in Sep-2021, around 14-Sep-2021, as reported, an unknown amount of time after receiving Fluad Quadrivalent, the patient experienced a bad reaction to flu shot. The patient felt weakness in leg and concluded that it just was a nightmare.  On 15-Sep-2021, the patient went to the doctor and told him of her complaints without realizing it had to do with the flu shot. It was hard for the patient to talk, as reported.  On 17-Sep-2021, the patient missed a dentist appointment because she simply could not go as a consequence of what she was feeling.  On 18-Sep-2021, reported as 'on the next day', the patient could not stand up.  On unspecified date in Sep-2021, the patient experienced weakness in legs, difficulty breathing, her oxygen levels went down to 88 percent, had weakness and was dizzy. The patient had never had problems with breathing and oxygen before.  On 23-Sep-2021, the patient experienced fast heartbeats, her heart rate went up to 118 beats per minute. On the same date, the patient went to the hospital, where she spent ten days (discrepant information).  On 30-Sep-2021, the patient was discharged from the hospital and she went home.  On an unspecified date, afterwards, the patient was sent to rehab for 43 days, because her legs were so weak that she kept fallin down. From there, the patient got scabies, even claiming she still had the dead eggs in her. From seeing a doctor, to being hospitalized, to rehab, the patient had gone through a series of treatment measures. In rehab, the patient was put on oxygen, she was taking it every day as reported and only recently stopped being on oxygen She was treated also with Breztri inhaler (budesonide, formoterol fumarate, glycopyrronium bromide).  At the time of the initial reporting on 07-Oct-2022, the patient had not recovered from the events of 'lower extremities weakness of', 'dizzy' and 'weakness', but was was recovering from the events of 'oxygen saturation low', 'difficulty breathing', 'falling down', 'heartbeats increased' and 'lower extremities weakness of'. The patient was still feeling weakness in legs and concluded it just had been a nightmare, she felt a lot better but still kinda dizzy and also weakness was not gone.  The outcome of the events of scabies and 'hard to talk' was not reported.   The reporter assessed all events as related to Fluad Quadrivalent, except for the events of scabies and 'hard to talk' for which causality was not reported. The patient stated she had a bad reaction to the flu shot and asked if she needs to get one this year.  The events the events  of 'dizzy' and 'weakness', 'saturation low', 'difficulty breathing', 'difficulty in standing','hard to talk', 'heartbeats increased' and 'lower extremities weakness of' were considered to be serious due to seriousness criterion of hospitalization.  Company comment: A female patient of an unspecified age was vaccinated with the suspect product Fluad Quadrivalent. As reported around 2 days after vaccination the patient developed weakness. On an unspecified date within the same month the patient experienced weakness in legs, difficulty breathing, oxygen levels went down to 88% and dizziness. As reported it was hard for the patient to talk. The patient also developed heartbeats 11 days following vaccination. The patient was falling down due to the weakness. During rehabilitation the patient developed scabies. Underlying medical history is significant for lung volume reduction surgery. Information regarding the concomitant medications has not been provided. More information regarding the related diagnostic findings is needed. Causality for the event fall is assessed as not related since it developed as a consequence of weakness. Causality for the event Scabies is assessed as not related due to biological implausibility. Causality for the events weakness, muscular weakness and dizziness could not be ruled out and is assessed as possibly related. Causality for the remaining three events is unassessable due to limited information provided.; Reporter's Comments: The patient stated she had a bad reaction to the flu shot and asked if she needs to get one this year.; Sender's Comments: A female patient of an unspecified age was vaccinated with the suspect product Fluad Quadrivalent. As reported around 2 days after vaccination the patient developed weakness. On an unspecified date within the same month the patient experienced weakness in legs, difficulty breathing, oxygen levels went down to 88% and dizziness. As reported it was hard for the patient to talk. The patient also developed heartbeats 11 days following vaccination. The patient was falling down due to the weakness. During rehabilitation the patient developed scabies. Underlying medical history is significant for lung volume reduction surgery. Information regarding the concomitant medications has not been provided. More information regarding the related diagnostic findings is needed. Causality for the event fall is assessed as not related since it developed as a consequence of weakness. Causality for the event Scabies is assessed as not related due to biological implausibility. Causality for the events weakness, muscular weakness and dizziness could not be ruled out and is assessed as possibly related. Causality for the remaining three events is unassessable due to limited information provided.