Table. Characteristics of Patients Who Experienced Potential Immediate Allergic Reactions to the First Dose of an mRNA COVID-19 Vaccine and Second Dose Outcomes.
| Institution | Cases, No. | Female, No. (%) | Age, mean (SD), y | No. (%) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Moderna | Pfizer-BioNTech | First-dose anaphylaxisa | Allergist skin testing performedb | Dose 2 administered | Dose 2 premedication givenc | Dose 2 administered within guideline-recommended windowd | Immediate allergic symptoms with dose 2e | Dose 2 tolerancef | ||||
| MGH | 76 | 66 (87) | 39.5 (12.7) | 60 (79) | 16 (21) | 6 (8) | 34 (45) | 65 (86) | 7 (11) | 62 (95) | 8 (12) | 65 (100) |
| BWH | 54 | 45 (83) | 43.0 (12.6) | 41 (76) | 13 (24) | 5 (9) | 30 (56) | 50 (93) | 11 (22) | 44 (88) | 7 (14) | 50 (100) |
| VUMC | 27 | 22 (81) | 49.8 (18.2) | 6 (22) | 21 (78) | 8 (30) | 5 (19) | 19 (70) | 15 (79) | 18 (95) | 7 (37) | 19 (100) |
| YSM | 25 | 23 (92) | 46.3 (13.3) | 20 (80) | 5 (20) | 7 (28) | 11 (44) | 18 (72) | 16 (64) | 18 (100) | 7 (29) | 18 (100) |
| UTSW | 7 | 7 (100) | 47.0 (13.2) | 3 (43) | 4 (57) | 6 (86) | 0 | 7 (100) | 1 (17) | 6 (86) | 3 (43) | 7 (100) |
| Pooled values | 189 | 163 (86) | 43.2 (14.1) | 130 (69) | 59 (31) | 32 (17)g | 80 (42) | 159 (84) | 50 (31) | 148 (93) | 32 (20) | 159 (100) |
Abbreviations: BWH, Brigham and Women’s Hospital; MGH, Massachusetts General Hospital; mRNA, messenger RNA; UTSW, University of Texas Southwestern Medical Center; VUMC, Vanderbilt University Medical Center; YSM, Yale School of Medicine.
Anaphylaxis defined as meeting at least 1 of the following criteria: Brighton and/or the National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network criteria.
Skin testing was variably performed in some higher-risk patients, of whom none were positive for polyethylene glycol 3350 with percutaneous skin testing.
The most common pretreatment was nonsedating oral antihistamines (47 of 50 patients).
Forty-two days, US Centers for Disease Control and Prevention (https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html).
All reactions experienced with dose 2 were lower in severity compared with first-dose reactions and none required treatment with epinephrine or urgent care/emergency department visits. Reaction symptoms included: tachycardia (n = 6), dizziness/lightheadedness (n = 6), throat tightness (n = 6), flushing/erythema (n = 5), swelling (n = 4), hives (n = 3), wheezing/shortness of breath (n = 3), hypertension (n = 2), tingling (n = 2), and nausea/vomiting/abdominal pain (n = 1). Numbers do not sum to 32 because some patients had more than 1 symptom. No patients experienced hypoxia, hypotension, bradycardia, metallic taste, or tingling.
Tolerance was defined as no immediate symptoms present, or if immediate symptoms were present, they were self-limited, mild, and managed with antihistamines only.
Of these 32 patients, 19 (59%) received and tolerated dose 2 (2 for MGH, 4 for BWH, 6 for VUMC, 1 for YSM, and 6 for UTSW).