NECK PAIN; LOW BLOOD CIRCULATION; SINUSITIS; STIFF LEG; VISION WAS VERY VERY UNUSUALLY SHARP; RASH ON LEG; HEAVY HEADACHE; COULDN'T CONCENTRATE; ANAPHYLAXIS; SWOLLEN LYMPH NODE; MUSCULAR PROBLEM; ITCHY LEGS; LITTLE ANXIOUS; This spontaneous report received from a patient concerned a 42 year old female unspecified race and ethnic origin.  The patient's height, and weight were not reported. The patient's concurrent conditions included microcytic anemia (which was inherited). She had her period on the day of the vaccine. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin, and batch number: Unknown, expiry date: unknown) dose was not reported, 1 total administered on 07-APR-2021 for prophylactic vaccination. The batch number was not reported and has been requested. No concomitant medications were reported. On the first day of vaccination (07-APR-2021), she was feeling very alert and she had very heavy headaches, as if her head was heating up like the laptop when overheated. On the second day (08-APR-2021), she woke up with a very stiff leg, and a rash on the same leg, which went away after she took a cold shower. She blamed the walk from the day before. Her headaches continued, but her vision was very unusually sharp. She couldn't concentrate or be in front of the computer for very long, which was also very unusual. On Monday (unspecified date in APR-2021), she experienced more headaches and strange sensations on the left side of my face. However, she suffered from sinusitis so she blamed that. On an unspecified date, she was driving. Her leg was still stiff; it was less stiff than before but it, intensified with the driving. She made sure that she was taking regular stops and did some icing, which however didn't seem to help. Her blood circulation was quite slow. On an unspecified date in APR-2021, she suddenly had anaphylaxis (rush of heat all over the body, confused) which she never had before. Her head was still feeling very weird. She was taken to hospital that night. It looked like it could have been a delayed reaction from the vaccine, since she never had any of these episodes before. She had similar intense episode on 25-APR-2021. Very intense leg stiffness, followed by a rush of heat all over the body, headaches and neck pain. She was very confused and scared because none of these intense episodes ever happened to her before. The hospital didn't find anything, other than muscular problems, but it seemed very weird to her that these effects happened so close to each other. She had a few lymphatic massages from a friend, who said the lymph nodes were very swollen, and that was possibly from the vaccine. The massages reignited the circulation, the legs were now feeling very itchy and she began to feel a little better. However, the doctors were investigating these events further with allergy tests. At the time of report, she felt like her body had returned to normal, she was just a little anxious (unspecified date) it would happen again. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from anaphylaxis, sinusitis, rash on leg, stiff leg, low blood circulation, swollen lymph node, couldn't concentrate, neck pain, muscular problem, itchy legs, and heavy headache, and the outcome of little anxious and vision was very unusually sharp was not reported. This report was serious (Other Medically Important Condition).; Sender's Comments: V0: 20210511816-COVID-19 VACCINE AD26.COV2.S-Anaphylaxis. This event(s) is labeled per RSI and is therefore considered potentially related.