passed out; almost delirious; couldn't lift leg; pain went all the way down left side of body; sweating; chills; felt heavy weight on chest; left leg hurting so bad like a charley horse; weak all over; allergic reaction; pain in left arm at injection site; felt extremely tired; A spontaneous report was received from a consumer, via notification from another manufacturer, concerning a 79 year-old female patient who experienced an allergic reaction (hypersensitivity); passed out (loss of consciousness); almost delirious (delirium); couldn't lift leg (femoral nerve injury); pain radiating down leg (pain); sweating (hyperhidrosis); chills; heavy weight on chest (chest discomfort); leg hurting like Charlie horse (muscle spasms); weak all over (asthenia); pain in left arm where she got the shot (injection site pain); felt extremely tired (fatigue).    The patient's medical history included sinus issues and drug allergies to glycopyrrolate, sulfa, meloxicam, erythromycin and azithromycin.  The patient stated that she had a long list of names and ingredients of things she is allergic to.  Products known to have been used by the patient, within two weeks prior to the event, included Amiodipine.    On 28 Jan 2021, approximately 12 hours prior to the onset of the symptoms, the patient received their first of two planned doses of mRNA-1273 (Batch number: 028120A) intramuscularly in the left arm for prophylaxis of COVID-19 infection.   The patient reported that she received the vaccine dose around 12:00 or 12:30 pm.  The patient reported that she woke up with extreme pain in the left side and in the left arm where she got the shot.  The pain went all the way down her body and she reported it as severe pain.  She reported that the pain would not go away.  The patient reported that she started sweating, had chills, and she felt heavy like a weight on her chest, but she was breathing okay.  Her leg on the left side started hurting so bad that it was like a big Charley horse that would not go away.   She got out of the bed and tried to see if she could stand on it, but she could not.  She tried to rub it, but it did not help.  She tried to walk on it, but by that time she was almost delirious.  She was sweating so bad and she was weak all over.  She had become extremely tired and she ended up laying on the floor because she could not get her leg to lift in order to get back in the bed so she just laid on the floor.  By that point, she did not know if she had passed out or fallen asleep, but she does not think she fell asleep because it was too much pain to sleep.  When she woke up and came to, the pain in her leg was gone.  However, she was still sweating.  She could not get back in the bed.  The following morning, she was extremely weak and tired.  She still felt heavy on her chest like something had been pushed on her.  She was hurting, weak, and tired, but the pain was not extreme like it had been that night.  She clarified the time of onset for this event was around midnight, but she could not look at the clock to confirm the exact time.  She reported the event either started the night of 28 Jan 2021 or early in the morning hours of 29 Jan 2021.  She called her doctor, Moderna, and the pharmacist to ask about the ingredients of the vaccine.  Treatment information was unknown.   Action taken with mRNA-1273 in response to the events  was withdrawn.  The events, passed out and pain in left leg, was considered resolved the following day.  The events of sweating, weakness, tiredness, and heavy chest was improved the following day.  The outcome of the events, allergic reaction, delirious, pain in left arm, pain in left side of body, chills, couldn't lift leg, was unknown.; Reporter's Comments: Based on the current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded.