Patients tolerate subsequent challenge after reaction to initial COVID-19 vaccine dose
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LOUISVILLE, Ky. — Most patients with an allergic reaction to an mRNA COVID-19 vaccine tolerated a subsequent challenge to it, according to a presentation at the American College of Allergy, Asthma & Immunology Annual Scientific Meeting.
These patients tolerated these challenges despite any underlying atopic comorbidities, Kristine Vanijcharoenkarn, MD, assistant professor in the division of pulmonary, allergy, critical care and sleep medicine at Emory University School of Medicine, said during her presentation.
“There have been multiple reactions that have been reported to these vaccines that were precluding a lot of patients from obtaining full vaccination status or even getting the first dose,” Vanijcharoenkarn said.
“We wanted to remove as many allergic barriers to vaccination as possible so we could vaccinate as many patients as possible and contribute to knowledge regarding these vaccine reactions,” she continued.
Also, Vanijcharoenkarn said, the researchers wanted to confirm the safety of the vaccine challenge protocol they developed for vaccinating patients with underlying severe allergic reactions and for revaccinations.
The study involved 53 patients (mean age, 52.4 years; standard deviation, 14.8; 89% women; 40.7% Black).
Common comorbidities included allergic rhinitis (50%), drug hypersensitivity (48%), food allergy (22%), eczema or dermatitis (19%), asthma (17%), anxiety (13%), depression (11%), autoimmune condition (11%), sinusitis (9%) and anaphylaxis (9%).
“The majority of these patients, 33 of them, had a first-dose reaction,” Vanijcharoenkarn said. “The rest of the patients had a history of severe underlying reaction that had precluded them from getting the vaccine.”
The patients in the group that had reacted to the first dose of the vaccine included 61% with an immediate reaction, 30% with a delayed reaction, and 9% with both an immediate and a delayed reaction.
The researchers gave the patients in both groups a challenge dose that was 10% of the standard vaccine dose, followed by 30 minutes of observation. When patients did not have any reactions, they then received the subsequent 90% of the dose.
Overall, 83% of the patients received the Pfizer vaccine for their first dose, and 17% received the Moderna vaccine. All of the patients then received Pfizer or Moderna for their subsequent dose, except for one patient who received the Johnson & Johnson vaccine.
All but one patient (98%) tolerated the full vaccine dose.
“She had immediate diarrhea, and we stopped the rest of the challenge,” Vanijcharoenkarn said.
Specifically, all the patients with type 1 hypersensitivity reaction concerns including hives and angioedema following mRNA COVID-19 vaccination tolerated subsequent vaccination with an mRNA vaccine. Most of these patients tolerated the same vaccine.
Similarly, all the patients who experienced a delayed reaction such as serum sickness to an mRNA COVID-19 vaccine tolerated subsequent mRNA COVID-19 vaccination, with 80% tolerating the same vaccine as their first dose.
All the patients who experienced immediate reactions to an mRNA COVID-19 vaccine tolerated the vaccine challenge as well, with 90% receiving the same vaccine that they had reacted to initially.
All three patients who experienced immediate and delayed reactions used the same vaccine for their second dose, with two of the three tolerating the challenge.
“Even with a first dose reaction, most patients tolerated the same exact vaccine,” Vanijcharoenkarn said. “Our challenge algorithm was a safe algorithm to use for vaccinating patients with this underlying history of allergy.”
The researchers additionally noted that further research is needed to elucidate the mechanism behind these reactions.