Multiple military branches are once again requiring flu shots for new recruits as a significant influenza outbreak grows at the Air Force's basic training center in San Antonio. As of Tuesday, at least 222 recruits at Lackland Air Force Base, part of Joint Base San Antonio, had been diagnosed with the flu, and four had been hospitalized, according to sources familiar with the situation. This marks a sharp increase from the 159 cases and two hospitalizations reported the previous week. The death of one recruit is currently under investigation to determine if it is linked to the outbreak.
The current situation marks a reversal from a policy change in April, when Defense Secretary Pete Hegseth made the annual flu shot optional for all troops, ending a requirement that had been in place since 1945. Hegseth stated at the time that the decision was based on individual choice, saying, "If you, an American warrior entrusted to defend this nation, believe that the flu vaccine is in your best interest, then you are free to take it; you should. But we will not force you."
However, the Army, Navy, and Air Force have since been granted exceptions to this policy, allowing them to reimpose the flu shot requirement for basic trainees, according to Pentagon spokesperson Sean Parnell. At the start of the outbreak in early June, only about 40% of new Air Force trainees at Joint Base San Antonio had received a flu vaccination. With the new exception, the Air Force aims to vaccinate all recruits in the current class and all new arrivals.
The Army is also planning to expand flu shot requirements in the coming weeks to include troops deploying overseas, first responders, child care and healthcare workers, prison staff, and soldiers participating in large-scale training exercises.
Military training environments, such as basic training, involve close proximity among recruits, with shared living quarters and communal facilities. This close contact can facilitate the rapid spread of illness. Stress and exhaustion among trainees can also compromise immune systems, making them more vulnerable.
Keon McDaniel, the Air Force recruit who died, experienced a medical emergency on June 12 during his sixth week of basic training. He was transported to Brooke Army Medical Center, where he later passed away. The Air Force has stated that the cause of the medical emergency is under investigation, with a comprehensive medical review underway.
Following the outbreak, some U.S. officials, including Representative Joaquin Castro, whose district includes Lackland Air Force Base, have criticized the decision to make the flu vaccine optional. Castro stated that the outbreak was an anticipated consequence of the policy change, calling it "a reckless decision that put troops in harm's way and undermined our military readiness."