How do allergy shots work? Allergy shots work by stopping Th2 cells from making IgE antibodies. The goal of Allergy shot immunotherapy is to change Th2 cells into Th1 or Treg cells. This way IgE antibodies are decreased. If IgE antibodies are decreased then your main allergy cells, the mast cell, cannot function and release histamine. Histamine is one of the main molecules responsible for allergy (runny nose, itchy eyes, hives, swollen throat). Allergy shots, or allergy immunotherapy, can help many people decrease their allergy responses. Although not everyone will respond to this type of treatment. Often adults with peanut allergy have such severe symptoms that they do not benefit from allergy shots. However, many other types of allergies can be improved with allergy shots over the course of a year. If you have any other questions please leave them in the comments section! I would be happy to go into additional details.

Sources:
https://www.ncbi.nlm.nih.gov/pmc/arti...

https://www.jacionline.org/article/S0...