A flu outbreak has torn through the basic training wing at Lackland Air Force Base in San Antonio, sickening more than 220 recruits and raising hard questions about War Secretary Pete Hegseth's decision, less than two months earlier, to drop the requirement that all troops get a flu shot.
The outbreak hit the 37th Training Wing, the Air Force's largest, which runs basic training for every enlisted recruit entering the Air Force, Space Force, Air Force Reserve, and Air National Guard. The wing, working with the 59th Medical Wing, has spent three weeks managing the outbreak, according to the Air Force. The setting made spread almost inevitable: Recruits sleep on bunk beds in open bays and eat at communal tables, the kind of close-quarters living that has fueled respiratory disease outbreaks among military personnel for centuries.
The episode took a darker turn with the death of a trainee, Keon McDaniel of the 737th Training Support Squadron, who died June 16 at Brooke Army Medical Center after a medical emergency in his sixth week of training. The Air Force has not said his death is connected to the outbreak, and a review is underway. The timing alone, though, is enough to demand answers.
The outbreak comes less than two months after Hegseth ended the decades-old requirement that troops receive an annual flu shot. He framed the change as a matter of personal liberty and religious conscience, calling the old mandate bureaucratic overreach with no place in a "lethal" modern force. Troops who wanted the vaccine remained free to get it, he said; they just wouldn't be forced to.
But ending a flu vaccine mandate in a setting built around forced proximity isn't rational. The Air Force itself has had to walk the policy back at Lackland, carving out an exception to require vaccination there again — a tacit admission that voluntary uptake wasn't enough. Since the mandate became optional, only about 40% of trainees have chosen the shot, down from a rate that had long been near 100%. Had Hegseth consulted the surgeons general in his department – the Army, Navy, and Air Force each has one – they would surely have objected to lifting the vaccine mandate.
The reaction in Congress wasn't uniformly favorable, even among Republicans. Senator Roger Wicker (R-MS), an Air Force veteran and chairman of the Senate Armed Services Committee, has noted the original mandate existed to keep the force ready to fight, and that service members relinquish certain freedoms the moment they take the oath. Rep. Joaquin Castro of San Antonio, whose district includes Lackland, called ending the mandate reckless and said an outbreak like this was foreseeable.
That tension — between individual medical autonomy and collective force readiness — is now playing out at Lackland, with hospitalizations, isolation protocols, and a grieving family waiting for answers. It's a tension Hegseth invited, and one the Pentagon should resolve in favor of readiness, not deference to individual preference in a setting where personal choices carry collective consequences.
This is also a familiar story. Infectious disease has historically killed more U.S. service members than combat — true from the Revolutionary War through World War I, when an estimated 45,000 American troops died of influenza or related pneumonia during the 1918 pandemic alone, more than were killed in combat that war. Not until World War II, with vaccines and antibiotics, did combat deaths outpace disease deaths.
The mandate Hegseth scrapped traces directly to that history. The military first required flu vaccination in 1945, partly because the 1918-1920 pandemic had so badly undermined troop readiness. The mandate was briefly dropped in 1949 and reinstated in the early 1950s once it became clear how readily the virus could cripple a fighting force — and it stood for the next seven decades, until this spring.
Influenza is not currently widespread nationally or in Texas, per CDC and state tracking, which makes the outbreak at Lackland localized but telling — a warning of what wider relaxation of the mandate could invite once flu season actually arrives. The vaccine is imperfect at preventing infection outright, but it reliably reduces the severity of illness and the risk of hospitalization and death — precisely the outcomes a barracks full of recruits is most vulnerable to.
The Air Force says containment is working, and recruits are being cleared to return to training as they recover. But the outbreak has reopened a debate that has simmered since April: whether decisions framed around individual liberty can coexist with the basic realities of military service. Disease moves fastest where people are packed closest together, and readiness has always depended on managing that risk collectively — not leaving it to each recruit to decide alone.
Hegseth's department should heed the Lackland lesson: Let science and history guide policy.
Henry I. Miller, a physician and molecular biologist, is the Glenn Swogger Distinguished Fellow at the Science Literacy Project. He was the founding director of the FDA's Office of Biotechnology.