Skip main navigation

Military Health System

Clear Your Browser Cache

This website has recently undergone changes. Users finding unexpected concerns may care to clear their browser's cache to ensure a seamless experience.

2023-2024 Mid-Season Influenza Vaccine Effectiveness Against Laboratory-Confirmed Ambulatory Influenza: DOD TRICARE Beneficiaries

Image of 48088663. This study presents the results of a vaccine effectiveness estimate against ambulatory influenza infections among Department of Defense TRICARE beneficiaries.

The DOD Global Respiratory Pathogen Surveillance Program1 used a matched case-test negative control study design to determine VE estimates against ambulatory influenza among DOD TRICARE beneficiaries. Specimens were collected from October 1, 2023 to February 17, 2024 among individuals with an influenza-like illness medical encounter, then analyzed either at the United States Air Force School of Aerospace Medicine or Landstuhl Regional Medical Center. An ILI encounter was defined as presenting with a fever (≥100.4°F) and cough, fever (≥100.4°F) and two or more additional symptoms (fatigue, body aches, sore throat, headache, sinus congestion, shortness of breath, chills, runny nose, loss of taste or smell, acute respiratory distress) or a physician-diagnosed ILI. The study excluded service members, who were evaluated separately by the Armed Forces Health Surveillance Division. 

Cases were individuals with a laboratory-confirmed positive influenza specimen, while controls were those with a specimen testing negative for influenza. An attempt was made to match each case to four controls by the month of specimen collection, but due to control availability, some analyses only had one case to three controls. Vaccination status was determined by utilizing the Aeromedical Services Information Management System or self-reporting through DODGRPSP questionnaires. Individuals were considered vaccinated if they received the vaccine at least 14 days prior to specimen collection, with exclusions for vaccines received within 14 days. Adjusted ORs and 95% CIs were calculated via multivariable logistic regression, adjusting for age group and geographic region. Adjusted VE estimates were computed as (1 - aOR) x 100. 

Click on the table to access a 508-compliant PDF version

The study identified 158 cases and 479 controls. Adjusted VE estimates for all DOD beneficiaries showed 35% effectiveness (CI: 4, 56) against overall influenza, 32% (CI: -8, 57) against overall influenza A, 40% (CI: -15, 69) against influenza A(H1N1)pdm09, 54% (CI: -31, 84) against influenza A(H3N2), and 67% (CI: 17, 87) against influenza B. For children, the adjusted VE estimate was 43% (CI: 0, 67) against overall influenza, while for adults it was 52% (CI: 11, 74) against overall influenza. 

VE estimates suggest statistically significant, low to moderate protection against overall influenza among all DOD TRICARE beneficiaries and adults, as well as against influenza B among all DOD TRICARE beneficiaries. VE estimates against overall influenza for children, overall influenza A for all DOD TRICARE beneficiaries, influenza A(H1N1)pdm09, and influenza A(H3N2) for all DOD TRICARE beneficiaries indicate low to moderate protection, but these results did not reach statistical significance. 

Reference

  1. Kwaah B, Gruner WE, DeMarcus L, et al. Surveillance trends for SARS-CoV-2 and other respiratory pathogens among US military health system beneficiaries, 27 September 2020–2 October 2021. MSMR. 2022;29(7):2-10.

You also may be interested in...

Report
Oct 1, 2023

MSMR Vol. 30 No. 10 - October 2023

.PDF | 1.29 MB

The October 2023 Medical Surveillance Monthly Report (MSMR) provides a review of the incidence of colorectal cancer among active component service members from 2010 to 2022; followed by a study of force protection risks in AFRICOM, INDOPACOM, and SOUTHCOM due to rapid diagnostic test failures for P. falciparum malaria from 2016 to 2022; then an update ...

Report
Sep 1, 2023

MSMR Vol. 30 No. 9 - September 2023

.PDF | 1.30 MB

The September 2023 MSMR provides the annual update of routine screening for antibodies to HIV among the active and reserve components of the U.S. Armed Forces; followed by a serological survey of Ross River virus (RRV) infection among U.S. Marine expeditionary forces who train in Australia; followed by a Surveillance Snapshot of the 10 leading ...

Article
Sep 1, 2023

Update: Routine Screening for Antibodies to Human Immunodeficiency Virus, U.S. Armed Forces, Active and Reserve Components, January 2018–June 2023

This report provides an update through June 2023 of routine screening results for antibodies to HIV among members of the U.S. military. From January 2018 through June 2023, approximately 7 million U.S. military service members (active component, reserve component, and national guard) were tested for HIV antibodies; 1,502 were identified as HIV ...

Report
Aug 1, 2023

MSMR Vol. 30 No. 8 - August 2023

.PDF | 1.02 MB

The August 2023 MSMR provides the most recent data from the active surveillance program for acute respiratory disease and Group A Beta-Hemolytic Streptococcus among U.S. Army basic trainees; then summarizes the case report of an extensively resistant E. coli in a returning traveler at Hawai'i's Tripler Army Medical Center; followed by a Surveillance ...

Skip subpage navigation
Refine your search
Last Updated: May 07, 2024
Follow us on Instagram Follow us on LinkedIn Follow us on Facebook Follow us on X Follow us on YouTube Sign up on GovDelivery