To the Editor:I read with great interest the special article entitled “mRNA vaccines to prevent COVID-19 disease and reported allergic reactions: current evidence and suggested approach” by Banerji et al in the Journal of Allergy and Clinical Immunology: In Practice.I would like to ask the authors to justify their recommendation for polyethylene glycol (PEG) skin testing for those patients in the “higher risk” for reaction to vaccine category.The authors state that they do not recommend skin testing with the vaccine because of “lack of information about sensitivity or specificity (and) unclear safety of skin testing.”The authors also state that PEG skin testing “could be considered” and “may be of value in shared decision making” in spite of also stating that “there is no confirmation IgE mediated reactions to PEG are responsible for reported reactions to the....COVID-19 vaccines.” Therefore, a skin test could be helpful when positive but does not rule out allergy when negative.Allergists performing PEG skin testing can therefore be deluding themselves until they stumble across a false negative. If lack of information about sensitivity is a reason not to skin test with the vaccine, why isn't it a reason not to skin test with PEG?