“These reactions could include symptoms such as itching or hives or flushing. The patients included were all advised by allergy specialists after their dose one reaction,” explains co-lead author Matthew S. Krantz, MD, of Vanderbilt University Medical Center.

Among 189 patients, 32 (17%) experienced anaphylaxis after their first dose of mRNA COVID-19 vaccine. A total of 159 patients (84%) went on to receive a second dose.

All 159 patients tolerated the second dose. Thirty-two patients (20%) reported immediate and severe allergic symptoms linked to the second dose. But these were self-limited, mild, and/or resolved with antihistamines alone.

“One important point from this study is that these immediate onset mRNA vaccine reactions may not be mechanistically caused by classic allergy, called immediate hypersensitivity or Ig-E-mediated hypersensitivity.

Re-exposure to the allergen causes the same or even worse symptoms,” says co-senior author Kimberly G. Blumenthal, MD, MSc, co-director of the Clinical Epidemiology Program within MGH’s Division of Rheumatology, Allergy and Immunology.

It’s safe for most individuals to receive a second dose of the mRNA COVID-19 vaccine, notes co-senior author Aleena Banerji, MD, clinical director of the Allergy and Clinical Immunology Unit at MGH.

“After first dose reactions, allergy specialists may be useful to help guide risk/benefit assessments and assist with completion of safe vaccination,” she says.

Source: Medindia