Q:

8/22/2013
My patient, a nurse was treated with epi and benadryl for throat closing/breathing difficulties immediately after receiving a flu vaccine in 2001. She is not nor ever was egg allergic. Will skin testing with flu vaccine be of any help in reassuring her that she may now safely receive a flu vaccine?

A:

Thank you for your inquiry.

Generically, one can answer your question in the positive. That is, yes, skin testing to influenza vaccine might be of assistance to you if your patient did have an IgE-mediated reaction to influenza vaccine administration. The fact that she is not allergic to egg would indicate, if this was truly an IgE-mediated event, sensitivity to another ingredient. This issue becomes complex because there are varying ingredients in different influenza vaccines, and there are several vaccines presently on the market. To illustrate this point, I have copied below (brand name withheld), randomly, the contents of three available influenza vaccines. As you can see there are different potentially culpable ingredients in each example. Each one of these ingredients could probably be detected by skin tests. For example vaccine 3 contains gelatin. Other potential culprits are the antibiotics.

Having said this, I think it would be helpful if you could find the vaccine that was given to her at the time of the event, and obtain the ingredients of that vaccine. You could then make sure that the vaccine you were going to administer (should you decide to do so) contained different ingredients if possible. For example, if the responsible vaccine contained gelatin, you could certainly easily find brands for readministration which do not contain gelatin (and I would still skin test before giving her the vaccine).

The other strategy you might employ would be a graded dosage regimen. If the skin test was negative, you might start with 0.1 cc as the initial dose and follow an hour later with 0.2, and an hour or so later with another 0.2.

In summary:
Assuming that your patient did have an IgE-mediated event, I would suggest the following:
a. Trying to obtain the vaccine she was given, and using a vaccine with different ingredients if possible.
b. Skin testing regardless to the vaccine you choose to use.
c. Considering, even if skin tests were negative, a graded dosage regimen as described above.

Finally, you can conveniently obtain the contents (via the package inserts) of all available influenza vaccines at the link copied below, which will connect you to the Institute for Vaccine Safety.

Thank you again for your inquiry and we hope this response is helpful to you.

VACCINE 1) contains sodium chloride (4.1 mg), monobasic sodium 342 phosphate (80 mcg), dibasic sodium phosphate (300 mcg), monobasic potassium phosphate 343 (20 mcg), potassium chloride (20 mcg), and calcium chloride (1.5 mcg). From the 344 manufacturing process, each 0.5 mL dose may also contain residual amounts of sodium 345 taurodeoxycholate (¡Â 10 ppm), ovalbumin (¡Â 1 mcg), neomycin sulfate (¡Â 3 nanograms [ng]), 346 polymyxin B (¡Â 0.5 ng), and beta-propiolactone (¡Â 2 ng).

VACCINE 2) Each 0.5 mL dose may contain residual amounts of egg proteins (<0.4 mcg), formaldehyde (¡Â10 mcg), polysorbate 80 (¡Â50 mcg), and CTAB (¡Â12 mcg). Each dose may also contain residual amounts of neomycin (¡Â0.02 mcg by calculation) and kanamycin (¡Â0.03 mcg by calculation), which are used during the initial stages of manufacture. The tip caps of the syringes may contain natural rubber latex. The syringe plunger does not contain natural rubber latex.

VACCINE 3) sodium chloride solution volume volume

Formaldehyde ©÷50 mcg ©÷100 mcg
Octylphenol Ethoxylate ©÷75 mcg ©÷150 mcg
Gelatin

Institute for Vaccine Safety

Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology