Another part of the Journal of Allergy and Clinical Immunology’s food allergy symposium addressed European research on food vaccines. Impetus for this research is the worldwide increase in food allergy and also the increasing frequency of anaphylactic shock from food allergy.
Since vaccine therapy has proven successful in treating respiratory allergies and has also worked to prevent recurrent anaphylaxis from insects, it stands to reason that it could help eliminate food allergy and prevent food-related anaphylaxis.
Four types of vaccines for food allergy have been studied in Europe (and other countries): oral, sublingual, epicutaneous and subcutaneous.
All of these methods have proven to be of some benefit. Unfortunately, the ones that lead to the best improvement seem to have more side effects. Between the two ingestion vaccines (immunotherapy), oral immunotherapy leads to better reduction in allergy than sublingual.
The oral route commonly leads to GI side effects such as heartburn, nausea, vomiting, cramps and diarrhea. The sublingual route was much less likely to cause these symptoms, but did lead to itching and swelling in the mouth. Epinephrine shots had to be given twice as often for reactions in the oral group as compared to the sublingual group.
But patients who were successfully treated from both groups were able to ingest the implicated food – such as peanut – without going into allergic shock.
Subcutaneous immunotherapy, which is how traditional allergy shots are given, was more effective than epicutaneous immunotherapy. But once again, the more effective format led to more frequent vaccine reactions and to greater need for epinephrine to treat some of the reactions. When either of these techniques was successful, it again allowed the patient to safely ingest the offending food.
The European study group is conducting new and longer studies of these various forms of immunotherapy. The studies will include children, adolescents and adults. They also are adding studies to compare the use of pharmaceutical-grade food extracts versus the use of the entire native food as a vaccine substrate to see which works better and is safer.