Document Type

Master's Culminating Experience

Publication Date



OBJECTIVE: To investigate the potential difference in vaccine effectiveness among Active Duty Air Force (ADAF) personnel vaccinated against influenza from 2007-2011. Particularly, to determine if any difference in the protection offered is based on sex, vaccine type, or both.

METHODS: The proposed study incorporated a cross-sectional design using the Department of Defense’s (DoD) comprehensive databases. Laboratory-confirmed influenza and other Influenza-Like Illness (ILI) cases were identified for each of the four influenza seasons of interest, vaccination status and history was then verified, and 2x2 tables were constructed in order to calculate odds ratios.

RESULTS: No consistent difference in vaccine effectiveness in regards to sex of the subject could be demonstrated. For the ’10-’11 season, males were 42% less likely to develop influenza than females (OR 0.5820, 95% CI 0.3400-1.009). However, this finding was directly contradicted by the two analyses conducted for the ’08-’09 season which demonstrated that males had an increased risk of influenza infection (OR 1.483, 95% CI 1.214-1.813 & OR 1.422, 95% CI 1.010-2.027 respectively). For the ‘07-‘08, ‘08-‘09, and ‘10-’11 seasons, subjects who received the injectable trivalent (TIV) form of the vaccine achieved significantly better protection against acquiring influenza than did those who received the nasal (LAIV) form (0.5088, 95% CI 0.3094 – 0.8264; OR 0.7266, 95% CI 0.6095-0.8663; OR 0.6724, 95% CI 0.4945-0.9111; & OR 0.5297, 95% CI 0.3189-0.8683 respectively). This did not hold true for either analysis conducted for the ’09-’10 season.

CONCLUSIONS: No demonstrable differences in influenza vaccine effectiveness were found among ADAF personnel vaccinated between 2007 through 2011 based on sex. However, during that same period of time, those who received the TIV form were better protected than those who received the LAIV.