Paul A. Offit, MD says that "Delayed-type hypersensitivity reaction due to vaccinations" are nothing to be concerned about.... really???? Just what is meant by delayed hypersensitivity reaction and is it really nothing to be concerned about?

delayed-type hypersensitivity (DTH) - a delayed hypersensitivity. See also cell-mediated immune response.
http://medical-dictionary.thefreedictionary.com/Delayed-Type+Hypersensitivity

cell-mediated immune response n. - The immune response produced when sensitized T cells attack foreign antigens and secrete lymphokines that initiate the body's humoral immune response. Also called cell-mediated reaction, cellular immune response.
http://medical-dictionary.thefreedictionary.com/cell-mediated+immune+response

cell-mediated immune response - a delayed reaction of the immune system, mediated primarily by sensitized T lymphocytes rather than antibodies. Cell-mediated immune response reactions are responsible for defense against certain bacterial, fungal, and viral pathogens; malignant cells; and other foreign proteins and tissues. Allergic dermatitis is an example of a cell-mediated immune response. Also called cellular hypersensitivity reaction, delayed hypersensitivity reaction, type IV hypersensitivity. Compare anaphylactic hypersensitivity.
Mosby's Medical Dictionary, 8th edition. © 2009, Elsevier.
http://medical-dictionary.thefreedictionary.com/cell-mediated+immune+response

So basically it is not an IgE response but  a T lymphocyte response but it can still be an allergy....

allergy /al·ler·gy/ (al´er-je) a hypersensitive state acquired through exposure to a particular allergen, reexposure bringing to light an altered capacity to react. See hypersensitivity. aller´gic
http://medical-dictionary.thefreedictionary.com/allergy

hypersensitivity /hy·per·sen·si·tiv·i·ty/ (-sen″sĭ-tiv´ĭ-te) a state of altered reactivity in which the body reacts with an exaggerated immune response to what is perceived as a foreign substance. The hypersensitivity states and resulting reactions are usually subclassified by the Gell and Coombs classification (q.v.).hypersen´sitive
http://medical-dictionary.thefreedictionary.com/hypersensitivity

So can a delayed-type hypersensitivity reaction be serious?

Delayed-type hypersensitivity reaction to anthrax vaccine.

Greidanus TG, Honl BA.
Evans Army Community Hospital, Fort Carson, CO, USA.

RESULTS: Two patients, 39 and 23 years of age, were seen with acute optic neuritis 1 month and 2 weeks, respectively, after anthrax booster vaccination and successfully treated with intravenous methylprednisolone. The first patient had a typical presentation and course of unilateral retrobulbar optic neuritis with excellent visual recovery. The second patient had a bilateral anterior optic neuritis and has required chronic immunosuppression to maintain his vision. Retinal and optic nerve autoantibodies were present in the second patient. No cross-reactive epitopes between anthrax vaccine and retina/optic nerve were identified.

 CONCLUSION: Optic neuritis is a potential adverse reaction of anthrax vaccination.Mil Med 2002 Jan;167(1):74-5
http://www.vaccinationnews.com/Scandals/feb_8_02/AnthrVaxReactionsLS.htm

An Algorithm for Treatment of Patients With Hypersensitivity Reactions After Vaccines
Robert A. Wood, MDa , Melvin Berger, MD, PhDb , Stephen C. Dreskin, MD, PhDc , Rosanna Setse, MD, MPHd , Renata J.M. Engler, MDe , Cornelia L. Dekker, MDf , Neal A. Halsey, MDa,d the Hypersensitivity Working Group of the Clinical Immunization Safety Assessment (CISA) Network

...Although these per-dose estimates suggest that true hypersensitivity reactions are quite rare, the large number of doses that are administered, especially for the commonly used vaccines, makes this a relatively common clinical problem.... [And this is only an immediate allergic reaction to an ingredient in the vaccine that is being addressed. Since the food particles vary from shot to shot, food allergies to traces of food protein from the oils in the adjuvant may or may not occur when a vaccination is given. - bfg]

Delayed-type reactions occur hours to days after exposure.27 The longest possible interval between exposure and the onset of symptoms is not completely clear, although most immunologists agree that reactions may occur up to 2 to 3 weeks after exposure. Most delayed reactions are classified as type 3 hypersensitivity and are attributed to formation of immune complexes, although other less well-defined mechanisms, including T cell–mediated processes, may also play a role. The most common signs of delayed-type reactions are rashes, which may include urticaria, erythema multiforme, and/or maculopapular eruptions. Although urticaria and angioedema are generally thought of as manifestations of immediate-type reactions, they can occur in delayed reactions as well. In the context of a delayed reaction, this is likely attributable to non–IgE-mediated processes such as complement activation by immune complexes, but late activation of the IgE system cannot be ruled out.  Angioedema may also occur, especially in association with urticaria or erythema multiforme. Although uncommon, arthralgias, arthritis,[arthritis is an uncommon reaction? How do you know that? Arthritis is very common. Few doctors would connect arthritis with a shot given two weeks beforehand - bfg]  joint swelling, serum sickness, and Henoch-Schönlein purpura may occur, as can a variety of other hematologic, renal, and gastrointestinal manifestations....

When deciding on administering additional doses of a vaccine that has been temporally associated with a hypersensitivity reaction, the risks for immediate and delayed type reactions differ considerably. IgE-mediated reactions have far more potential to cause life-threatening symptoms, such as airway obstruction, hypotension, and full-blown anaphylaxis. Although non–IgE-mediated delayed-type reactions may be very uncomfortable, they are rarely dangerous.... [But since they have not even considered the food allergies as being caused by the vaccines, and the other health problems that they are probably discounting as being due to the vaccine, "rarely dangerous" means what? The risk of getting sick from a disease that the vaccine supposedly prevents is less than getting a serious side effect from the vaccine. But they haven't added in all of the serious side effects! - bfg]

Published online September 1, 2008
PEDIATRICS Vol. 122 No. 3 September 2008, pp. e771-e777 (doi:10.1542/peds.2008-1002)
http://pediatrics.aappublications.org/cgi/content/full/122/3/e771
 

First, what is the difference between an allergy and a side effect? As with any medication, vaccines can have side effects such as fever, rash or local redness or swelling. This is not an allergy. An allergy is when the body reacts to a specific substance. An allergic reaction can be a rash, shortness of breath or swelling of the face, and these, almost immediately, or within an hour after the injection. As an example, the MMR (Measles, Mumps, Rubella) vaccine can cause a rash that occurs 7-10 days after the infection. This is not an allergic reaction. This is a side effect of the MMR vaccine itself. [So the allergy that the MMR may cause to one of the ingredients in the vaccine, if it doesn't react immediately, is a side effect and not an allergy because IgE may or may not be involved? But what about all the other Ig- responses - IgM... etc?  How many ways can we split a hair? - bfg]

http://www.drpaul.com/library/VACALLERGY.html

She says she’s allergic to penicillin, but her doctor calls it a “drug hypersensitivity.” What’s the difference?

December 2007

Q. My wife can’t take penicillin or any drug in the penicillin family. She says she’s allergic to penicillin, but her doctor calls it a “drug hypersensitivity.” What’s the difference? [Splitting hairs.... terminology.... medical BS..... - bfg]

A. An allergic reaction to a drug is one form of drug hypersensitivity. Both fall under the larger category of adverse drug reactions—unwanted effects of a particular medication. Most adverse drug reactions don’t involve the immune system, but both allergy and hypersensitivity do. They occur when a person’s immune system reacts to the medication or to substances produced when the body processes the medication.

An allergic reaction most frequently occurs when the drug is given either intravenously (into a vein) or by injection. It is less likely when a drug is taken by mouth. [Read it again. An allergic reaction is more likely to occur from an injection than eating something... - bfg]    The allergic reaction occurs only when a person has had a previous exposure to the medication....    [Babies are not BORN ALLERGIC!! It comes from the vaccination they are given often before they leave the hospital to go home!!! - bfg]   

Symptoms of drug hypersensitivity include hives or a skin rash, wheezing, and swelling. The most serious reaction is anaphylaxis, which is potentially life-threatening and thus a medical emergency. Although these symptoms generally occur within minutes to hours after taking the drug, they can also appear a week after the medication has been discontinued. [And is there any reason to think that this cannot occur from a vaccination? -bfg]

http://www.healthmonitor.com/asktheexperts/allergiesasthma/

The first DTH reaction described used only the tuberculin antigen (tuberculin reaction), but the definition was later expanded to include cell mediated reactions to other bacterial and viral antigens, responses to pure protein with adjuvant or haptens, and host responses to allograft.

Tuberculin Reaction
The classic form of DTH is induced by injecting an antigen preparation of Mycobacterium tuberculosis intradermally....


Jones-Mote Hypersensitivity: Protein-Adjuvant Reactions
            Closely related to the tuberculin reaction, is the host response to pure protein mixed with an adjuvant. This form of DTH was discovered in 1929 by Louis Dienes. He demonstrated that when ovalbumin, an egg white protein that is normally not immunogenic, is injected into a tuberculosis tubercule, the patient would become sensitized to the protein.[10] Later with the introduction of Freund's adjuvant, the reaction could be mimicked by mixing the protein with killed mycobacterium in oil.[11] When it was discovered that any pure protein mixed with adjuvant could induce an immune response, the DTH reaction was termed the Jones-Mote reaction since it was fundamentally different from the tuberculin reaction in one remarkable aspect.[12,13] ...

Finally, it is necessary to view DTH not as an individual phenomenon but rather a group of related responses to antigen. These include the tuberculin reaction, Jones-Mote reaction, contact hypersensitivity and graft vs. host disease.... It is clear that cell mediated immunity must be highly adaptable and therefore variable. The phagocyte (monocyte/macrophage) is involved in all of these responses, sometimes as a host for the pathogen, but more often as an effector cell. The exact mechanism by which the macrophage is activated is still being debated but it is clear that a T cell is required to initiate the response. When T cell or macrophage function is compromised the entire complement of cell mediated immunity is affected. This leads to a profoundly immunocompromised state in the host. Of course, in infection this can be lethal, but in allograft rejection it can be life saving. Finally, DTH must be viewed not as a host response in and of itself but rather one component of an interrelated coordinated host response to disease.
http://dermatology.cdlib.org/DOJvol5num1/reviews/black.html

Basically, I would say that all food allergy reactions fall under the delayed-hypersensitivity reaction immune responses. And a food allergy that leads to anaphylaxis is definitely serious. Having a "profoundly immunocompromised state sounds serious to me. So does arthritis, juvenile rheumatoid arthritis, and optic neuritis. I submit that the medical community has basically ignored delayed-hypersensitivity reactions and when they have occurred have attributed them to something other than the vaccination.