Vaccine Administration Errors: Wrong Vaccine (Now What?)

Millions of vaccines are administered yearly in the US in a variety of settings by individuals with very different levels of training. So, mistakes happen. In a previous segment we looked at vaccines inadvertently given via the wrong route. Let's look at another error category reported through the Vaccine Adverse Event Reporting System (VAERS): wrong vaccine.

A pediatrician's vaccine refrigerator is full of different vaccines. Most will have two hepatitis A vaccines (one for children, one for those over 18 years of age).

What would you do in the following scenario?

A 19-year-old, 110-pound female is due for her second hepatitis A vaccine having received the first dose 15 years earlier. Your nurse reports to you that she inadvertently gave the adolescent the 0.5 cc child hepatitis A vaccine dose, not the adult 1.0 cc dose.

You tell her:

A. Go ahead and give another 0.5 cc dose of the child hepatitis A vaccine at the same site and the dose will count.
B. Go ahead and give the adult 1.0 cc dose at a different site now
C. Have her return in 30 days for the adult 1.0 cc dose; today’s dose does not count.
D. Go ahead and give the 1.0 cc adult dose today and have her return in 6 months for dose two since too long an interval has occurred since her first dose.
E. Due to her weight, the half dose is adequate. After all, her 17-year-old, 220-pound brother would only receive the 0.5 cc dose.

Please click below for answer and discussion.

The best answer is B. Go ahead and give the adult 1.0 cc dose at a different site now.

In general, if a vaccine is under-dosed then that dose does not count. So, for example, if an individual pulls away from an IM shot and not all the vaccine is administered then the full dose needs to be repeated. There are two exceptions: If someone sneezes out FluMist or a baby spits up some of the rotavirus vaccine, the dose still counts and does not need to be repeated.

Option A is incorrect. Split IM doses are never acceptable.
Option B is the best answer.
Option C is okay, but delays protection and means an extra visit for the patient, assuming she shows up. Option D is wrong. No vaccine series needs to be repeated or restarted due to excessive time intervals between doses.
Option E also is wrong. Vaccine dosing is generally not based on weight. Immune response varies more with age than with weight. Generally speaking, antibody levels are higher with younger subjects with most vaccines.