You're a pharmacist at a large military training base. A couple of cases of varicella (chicken pox) are diagnosed in the 2,000+ member training wing. The training wing commander comes to the medical group asking what to do to keep this from becoming an epidemic within the training wing and losing a lot of training days to the chicken pox. Despite the cost and the current shortage of vaccine, he wants you to immunize the entire wing to protect others from the chicken pox and minimize lost training days. With this request in hand, the medical group commander comes and asks you for advice.

What do you tell him? Do you vaccinate everyone or not? Why or why not? Any other options? What's your recommendation(s) to the commander?

In a study published in 1998 in Military Medicine, the cadet wing (~ 4,000 members strong) of the USAF Academy was faced with just this scenario. Bottom line was a cost benefit analysis showed it was actually less expensive to draw serum titers on all the cadets and immunize only those found to be susceptible instead of immunizing everyone. The authors estimated an annual cost savings of $30,000. See reference #1.

A couple of caveats to consider when faced with such a situation:

1) Serum titer testing IN BULK is fairly inexpensive. If done IN BULK, common titers for things such as varicella, measles, rubella, Hepatitis B, and mumps range from $2.50 to $4.00 a test. The price per test skyrockets when only one or two titers are done. All the set up and reagent cost gets spread out over all the tests instead of just one or two.

2) Pre-testing is reasonable for common diseases or for those which patients have a high likelihood of already having the disease or getting the vaccination. To do a pre-vaccination screening for measles or varicella is probably reasonable and likely cost effective. A similar scenario for Japanese encephalitis or cholera or plague is probably NOT cost effective. In these cases, without proof or prior vaccination or disease or contraindication, you'd give the vaccine without serum titer testing.

3) If there's doubts about whether someone is susceptible or not, it's probably reasonable to give them the vaccine, barring any contraindications. Revaccination of an already immune individual is generally safe. Revaccination may cause a slightly greater incidence of local reactions but these are usually limited to a sore arm.

Some great sources for vaccine and immunizations information is:

Immunofacts - run By LTC (Dr.) John Grabenstein - http://www.immunofacts.com/

Centers for Disease Control and Prevention - http://www.cdc.gov/nip/

Advisory Committee on Immunization Practices - http://www.cdc.gov/nip/ACIP/default.htm

DoD Anthrax Vaccine Immunization Program - http://www.anthrax.osd.mil/HTML_interface/default.html

REFERENCES

- Burnham BR, Wells TS, Riddle JR. A cost-benefit analysis of a routine varicella vaccination program for the United States Air Force Academy cadets. Mil Med 1998;163:631-4

- Smith KJ, Roberts MS. Cost effectiveness of vaccination strategies in adults without a history of chickenpox. Am J Med 2000;108:723-9.

- Gayman J. A cost effectiveness model for analyzing two varicella vaccination strategies. Am J Health-Syst Pharm 1998;55:S4-8.