Anthrax Vaccine Adsorbed (AVA) and SF-36v2 Physical and Mental Functional Status Scores In the Anthrax Vaccination Program (AVP)

Background: In 2002 CDC initiated the AVP to provide voluntary pre-exposure vaccination with AVA for persons at high risk of exposure to B. anthracis spores.  There has been concern that AVA could be associated with long term impairment of mental and/or physical health.

Objectives: To ascertain whether physical and mental functional status, as measured by the SF-36v2 health survey (Medical Outcomes Trust, Boston, MA), of AVA recipients and controls changed differently over time.

Methods: We enrolled 576 Laboratory Response Network workers: 437 in AVP, 139 controls.  The exposed group received AVA under then-current ACIP recommendations of 0.5 mL doses given SQ at 0, 2, and 4 weeks, and 6, 12, and 18 months, followed by annual boosters.  Surveys were completed just before injection at 0, 12, and 30 months.  We analyzed the SF-36 physical and mental component scores (PCS and MCS) using linear mixed models; the subject-level response variables were subsequent MCS or PCS minus baseline score (MDIF and PDIF).  The reported national average MCS and PCS is 50 points and can range from 0 to 100, with larger values being more favorable.

Results: Average baseline PCS\MCS were 55.42\54.98 among exposed, 54.82\51.02 among controls.  The mean PDIF decreased from -0.45 at 12 months to -0.90 at 30 months among exposed, and  decreased from -0.49 to -1.78 among the controls (p=0.30 for change over time between the exposure groups) .  The mean MDIF decreased from -1.57 to -2.32 among exposed, and increased from -1.91 to -0.43 among the controls (p=0.06 for change).

Conclusions: We found no significant difference between exposed and controls in how PCS changed over time. Although this difference in MCS approached statistical significance, the magnitude was small.  These results do not favor an association between receipt of AVA and an altered health related quality of life over a 30-month period.