Surveillance and Vaccine Effectiveness Results from the Department of Defense (DoD) Global, Laboratory-Based, Influenza Surveillance Program
Influenza has the potential to cause high morbidity rates and undermine the readiness of the military population. Military members and their families are often stationed in areas where new strains are likely to appear and their high mobility across the world could result in the spread of a pandemic strain.
The DoD Influenza Surveillance Program is a year-round sentinel-based program where more than 80 pre-selected DoD sites worldwide are asked to submit 6-10 respiratory specimens per week from patients who meet an influenza-like illness case definition, along with a patient questionnaire, in order to document valuable epidemiologic data. A case-control method was used to calculate 2013-2014 mid-season influenza vaccine effectiveness (VE) estimating the effectiveness of the vaccine against currently circulating influenza strains.
The program collected and tested 3,079 specimens from 1,283 service members, 1,573 dependents (spouses/children), and 223 retirees/other beneficiaries. 989 specimens were positive for influenza A and 58 specimens were positive for influenza B. The program also identified 1,124 other respiratory pathogens. Mid-season VE analyses found statistically significant VE among military dependents/retirees for overall vaccine type (66% [50.91, 76.19]) and inactivated influenza vaccine type (73% [59.59, 82.73]) analyses. A service members’ only analysis did not demonstrate significant VE among overall or vaccine specific analyses.
With more than 80 sentinel sites across the world submitting specimens, the DoD Influenza Surveillance Program has the ability to identify strains that are currently circulating and track the genetic changes of strains through molecular sequence analysis. The program demonstrated moderate VE against medically-attended influenza among the dependent/retiree population. The same could not be demonstrated among the service member population; there is no single clear reason for this and this finding does deserve further scrutiny.
L. Demarcus, None