Half a flu shot for patients on immunotherapy? Seattle, WA


I work at an allergy/immunology clinic where most of our patients are on monthly immunotherapy injections for chronic allergies. Many of these patients are severely allergic to many things and are often very concerned about receiving a flu vaccine. For some reason I have had several patients request that they receive half a dose of a flu vaccine one week and the other half the next week in order to decrease the likelihood of a reaction. I am fairly new to this field and have never heard of this before. However, patients are telling me that the previous nurse administered their flu vaccine in this fashion for the past few years. CDC guidelines do not indicate giving a decreased dose for any reason. If an anaphylactic reaction has occurred in the past from a flu vaccine I know that that person is not a candidate for receiving the vaccine. Has anyone heard of this before? Please offer your thoughts.

Specializes in Reproductive & Public Health. Has 10 years experience.

hmmm. I know that half doses have been theoretically shown to be effective (in studies assessing best guidelines for flu vax shortages). HOWEVER, we know that an immunocompromised person would already be LESS likely to mount a good antibody response to the vaccine, and spacing the dose like that seems like it would decrease the efficacy. But I am not an immunology nurse, and that is pure conjecture on my part.

I'm assuming that the nurse administered the vaccine in a split dose based on the orders of the provider. Otherwise she has no business messing with dosages like that.

BeachsideRN, ASN

1,722 Posts

Specializes in NICU, Trauma, Oncology. Has 9 years experience.

They do half doses in children under 1 year.

Has 33 years experience.

I have never heard of this practice. IF the vaccine is not given in a full dose at one time is it still as effective as the one dose?? I do question this practice. If the patient was going to have an allergic reaction wouldn't it be with any egg derivative? I know we have given flu shots to CA patients who were not on chemo.

tyvin, BSN, RN

1,620 Posts

Specializes in Hospice / Psych / RNAC.

What does their doctor say?

Trauma Columnist

traumaRUs, MSN, APRN

165 Articles; 21,214 Posts

Specializes in Nephrology, Cardiology, ER, ICU. Has 31 years experience.

From the CDC website:

Flu vaccine is still available and recommended for almost everyone 6 months of age and older. If an adequate supply of adult formulation is available in the community, CDC does not recommend that providers combine two 0.25mL doses of pediatric influenza vaccine to vaccinate a single individual who requires a 0.5mL dose of vaccine.


[h=3]Should I repeat a dose of influenza vaccine that is less than the recommended dose (0.25mL for children 6-35 months; 0.5mL for persons 36 months and older)?[/h]If less than an age-appropriate dose of influenza vaccine is administered it should NOT be counted as valid regardless of the route it was given, and should be repeated.

Seasonal Influenza Vaccine Dosage & Administration | Seasonal Influenza (Flu) | CDC

So, no the "half dose" way of administering flu vaccines is NOT correct. I work with truly immunocompromised transplant pts and they all get the full dose at one time.

Specializes in Reproductive & Public Health. Has 10 years experience.

i'm really curious as to whether this RN was following a provider's orders when she administered the vaccine this way. I hope so, and I hope the provider had a solid rationale.