Data support second COVID-19 vaccine dose, even when allergic reaction occurs with first

Most patients with “immediate and potentially allergic reactions” to the Pfizer/BioNTech and Moderna COVID-19 vaccines tolerated a second dose, researchers reported in JAMA Internal Medicine.

Matthew Krantz, MD, a clinical fellow in the allergy/immunology fellowship program at Vanderbilt University Medical Center, and colleagues retrospectively analyzed data from 189 adults (mean age, 43 years; 86% of them women) from several regions of the United States who were administered either the Pfizer (n = 59) or Moderna (n = 130) vaccines from Jan. 1 to March 31.

According to the researchers, flushing or erythema (28%) were the most frequently reported first-dose reactions, followed by dizziness or lightheadedness (26%), tingling (24%), throat tightness (22%), hives (21%) and wheezing or shortness of breath (21%). Among the entire cohort, 17% met anaphylaxis criteria (ie, symptoms began within 4 hours of the first dose, patients experienced one or more allergic symptoms and they received a referral for an allergy/immunology consultation).

Krantz and colleagues reported that 159 patients (84%) received a second dose. Of these patients, 30% were given an antihistamine premedication before receiving their second dose.

“All 159 patients, including 19 individuals with first-dose anaphylaxis, tolerated the second dose,” Krantz and colleagues wrote. “Thirty-two reported immediate and potentially allergic symptoms that were associated with the second dose that were self-limited, mild, and/or resolved with antihistamines alone.”

The CDC has previously recommended that patients who experience allergic reactions to the first dose of the Pfizer or Moderna vaccines receive the Johnson & Johnson vaccine, according to the researchers.

However, given the new findings, “it may not be necessary to consider this, to our knowledge, largely unstudied alternative mixed-series approach,” Krantz and colleagues wrote.