Patient came into clinic for first dose COVID-19 vaccine. Patient preferred to receive Moderna vaccine. Vaccine Screening checklist completed by patient, EUA Moderna Fact sheet given and reviewed with patient. Patient received Moderna Lot # 007M20A in Left deltoid Given by RN at 1120 AM. Informed to remain in clinic for 15 minutes after receiving vaccine. At 11:30AM patient reported to administrative assistant that she ?wasn?t feeling well.? Administrative assistant notified RN. RN brought patient into exam room to assess patient reports ?feels like my heart is pounding.? Vital signs at 1133AM BP 133/93, OZ 99% on room air, 99.1 F temperature, Heart rate 77, and respiratory rate 16. Radial pulse felt normal, not bounding or thready.  Heart rate on auscultation was WNL. Patient denied any feelings of difficulty breathing, tingliness in lips or face, just states ?I can feel my pulse in my ears.? Patient sitting up and able to have a conversation with RN without difficulty. Patient states the only medication she takes is her inhaler for asthma, and she ate breakfast of grits this morning. RN brought patient some water. At 1145 patient stated she felt slightly dizzy. Patient was wearing a heavy jacket, and two sweatshirts, RN advised patient to take off a couple of layers to try and cool body down a little bit. Patient laid back on bed on right side and rested.  Vital signs at 1153, patient back to sitting up, Blood pressure of 114/81, temp 98.9F, O2 saturation of 100% on room air, Heart rate 75bpm, Respiratory rate 16. RN opened window in exam room, patient felt better with some fresh air. Patient states she ?isn?t dizzy anymore and her heart still feels like it is pounding but not as bad.? RN attempted to call Medical director  to report but call from exam room phone did not go through. RN opened patient?s chart and noted allergies of azithromycin (hives), seafood (severe but unknown response), and seed (anaphylactic reaction). On patient?s vaccine screening form patient only notified or admitted to azithromycin allergy. RN educated patient on allergic responses and caution to take with vaccines, as patient has had an anaphylactic reaction in the past. Patient used to have an epi pen but does not carry one anymore. Patient still denies any tingliness around lips/face, difficulty breathing, no swelling noted. Vital signs checked 1215pm blood pressure 126/90, O2 saturation 100% on room air, Heart rate 74, temp 98.9, and respiratory rate 17.  Patient denies feeling dizzy, states her heart doesn?t feel like it is bounding, it?s better but maybe not totally back to normal yet. Patient able to stand and walk around without getting faint or dizzy. RN called Medical director  phone went through and notified of patient?s response and current status. RN informed patient to call 911 or go to the ER if she feels dizzy again or like her heart is racing. PHN reviewed emergency signs of an allergic reaction (anaphylaxis) and patient able to teach back that she will go to the ER immediately if she starts feeling those symptoms of chest pain, difficulty breathing, tingliness around mouth/face/throat, or any swelling. RN suggested to patient to maybe receive her 2nd dose of the vaccine at the hospital. RN walked with patient out of clinic, patient doing well, and is ?feeling better.?