Briefly, patient had severe side effects until 16 days post vaccination #1, when she developed hives. Unfortunately, by that time, an new medication had been introduced which clouded the picture as to which product was the offending agent. Please see continuation page for further details. Chronologically, the events occurred as follows: Day 1, 01/02/2021, first shot, Right Deltoid. Headache (HA), muscle cramps, especially right side of neck and right trapezius area (expected side effects). Day 9, 01/11/2021, Right upper arm(posterior) deltoid area, red, hot, swollen, but no itching or significant pain. Erythema covers greater than half the circumference of the upper arm. Center of erythema is the injection site. Day 11, 01/13/2021, Patient see her Ophthalmologist for xerophthalmia, possibly secondary to ocular rosacea, given Rx for Doxycycline 100mg, 1 BID x 14 days. Has not taken Doxycycline previously. No know sensitivity. Day 13, 01/15/2021, Hives. Started on chest. Patient adds liquid Benadryl and OTC Cortaid HC topical cream (hydrocortisone) 0.5% to daily medications. Breathing has not been affected. Day 19, 01/21/2021, First patient visit with history as above, Is it the vaccine or the Doxycycline that has caused the hives?  Consider the vaccine but the Doxycycline is more likely because of timing. Discontinue the Doxycycline. Day 19, 01/21/2021 continued, Start prednisone taper per usual instructions for asthma (10mg tabs, # tabs: 5/d, 4/d, 3/d, 2/d, 1/d, 1/2/d x 4d and stop). Rx for mometasone topical ointment 0.1% use until hives/discomfort resolved. Continue other allergy medications. Discontinue the Benadryl (too sedating). Until this time, reactions were considered at the upper end of expected side effects for the vaccine, i.e. redness around injection side, HA, muscle cramps.  (? Will taking the prednisone cause the vaccine to be ineffective? Unknown.) Since the allergen is considered to be Doxycycline, and the patient works at a large medical facility, she is advised to get the second dose of vaccine as planned. Day 21-22, 01/23-24/2021, Hives gone within 48 to 72 hours of starting prednisone taper; Day 24, 01/26/2021, Second shot. Covid19, Moderna, Lot # 042L20A, Intramuscular, Right Arm. Hives begin within 12 hours of vaccination. More extensive than first hives. Continue all meds. HA and cramps worse than with first shot, patient told that this is common. No respiratory distress. The VAERS report asks about vaccines given with the previous month, but does not ask about subsequent months or vaccines requiring more than one injection. Day 25, 01/27/2021 day 2 after 2nd shot, Second patient visit. Increase prednisone back to 20mg/day, Rx written to cover extra tabs needed. Hives over trunk, anterior and posterior, and beginning to appear on extremities. No respiratory distress. Rx for updated EpiPen which she carries for asthma and allergic reactions.  Has had two episodes of anaphylaxis, unknown etiology, in the distant past, i.e. years ago. Day 33, 02/04/2021 or day 3 after 2nd shot, 3rd patient visit. Hives gone by Day 28, 01/30/2021, Saturday, 72 hours after prednisone increase to 20mg QD. Feeling better. Gather info for VAERS. Patient brings shot record from work, where shot was given for lot numbers. Day 34, 02/05/2021, Day 10 after second shot, Hives are back at 0200. They awaken patient from sleep because she feels her skin is "on fire." They are more extensive than the second episode, including buttocks and face this time. No respiratory distress. She increases the prednisone to 50 mg per day for the next 2 days.  Since the hives are not improving she goes to an ER/Clinic. The ER doctor has her begin taking 40mg prednisone per day for the next 5 days and then discontinue. Day 38, 02/09/2021, day 14 after second shot, Spoke with the patient on the phone. Hives had resolved by 72 hours. Has been back to work and is doing "OK," at the moment. She needs to restart the doxycycline but I advise she wait a full 2 weeks after this current resolution of the hives before re-trying the antibiotic in the event that she is sensitive to both the vaccine and the doxycycline. And to be prepared, that she may have hives again within 48 hours of starting the doxycycline.