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Population-Based Incidence, Severity, and Risk Factors Associated with Treated Acute-Onset COVID-19 mRNA
Eric Macy1, Shalin Pandya2, Javed Sheikh2
1Allergy Department, Kaiser Permanente Southern California, San Diego, Calif.
Background:
COVID-19 mRNA vaccination-associated acute-onset hypersensitivity reactions have caused anxiety and may be contributing to vaccine hesitancy.
Objective:
To determine the incidence, severity, and risk factors for treated acute-onset COVID-19 mRNA vaccination-associated hypersensitivity reactions in a well-characterized population.
Methods:
All Kaiser Permanente Southern California (KPSC) members who received COVID-19 mRNA vaccinations between December 15, 2020, and March 11, 2021, at a KPSC facility were identified and characterized, along with all treated acute-onset vaccination-associated hypersensitivity events.
Results:
We identified 391,123 unique vaccine recipients (59.18% female, age 64.19 ± 17.86 years); 215,156 received 2 doses (53.54% Moderna), 157,615 only a first dose (50.13% Moderna) (1961 [1.46%] >2 weeks late getting a second dose), and 18,352 (74.43% Moderna) only a second dose. Only 104 (0.028%) (85.58% female, age 53.18 ± 15.96 years) had treated first dose events, 68 (0.030%) Moderna. Only 32 (0.014%) (93.75% female, age 57.28 ± 17.09 years) had treated second dose events, 21 (0.016%) Moderna. Only 2 (0.00033%) vaccinations resulted in anaphylaxis. Only 27 (20.77%) of those with treated first dose reactions failed to get a second dose. Only 6 of 77 (7.8%) with first dose reactions also had second dose reactions. Individuals with treated events were more likely to be female (P < .0001), younger (P < .0001), and had more pre-existing drug "allergies" (2.11 ± 2.12 vs 1.02 ± 1.41 [P < .0001] for average recipients).
Conclusions:
Treated acute-onset hypersensitivity events were mostly benign, more common with first COVID-19 mRNA vaccine doses, more likely to occur in younger females with typical risk factors associated with multiple drug intolerance syndrome, and very unlikely to be primarily immunologically mediated.
Insights
Acute hypersensitivity reactions following COVID-19 mRNA vaccines are rare and typically benign. These events are more common in younger females and unlikely to be immunologically mediated.
Area of Science:
- Immunology
- Vaccinology
- Public Health
Background:
- Acute-onset hypersensitivity reactions to COVID-19 mRNA vaccines can cause public anxiety and contribute to vaccine hesitancy.
- Understanding the incidence, severity, and risk factors of these reactions is crucial for public health initiatives.
Purpose of the Study:
- To determine the incidence, severity, and risk factors for treated acute-onset hypersensitivity reactions following COVID-19 mRNA vaccination.
- To characterize these events in a large, well-defined population.
Main Methods:
- A retrospective analysis of Kaiser Permanente Southern California members who received COVID-19 mRNA vaccinations between December 15, 2020, and March 11, 2021.
- Identification and characterization of all treated acute-onset vaccination-associated hypersensitivity events.
Main Results:
- Out of 391,123 vaccine recipients, treated hypersensitivity events were rare: 0.028% after the first dose and 0.014% after the second dose.
- Anaphylaxis occurred in only 0.00033% of vaccinations.
- Individuals experiencing treated events were more likely to be female, younger, and have a history of drug "allergies".
Conclusions:
- Treated acute-onset hypersensitivity events following COVID-19 mRNA vaccination are generally benign.
- These reactions are more common with the first vaccine dose and occur more frequently in younger females with risk factors for multiple drug intolerance syndrome.
- The events are unlikely to be primarily immunologically mediated.
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