The Air Force has re-implemented a flu shot requirement for trainees after more than 200 fell ill due to an outbreak at the Lackland Air Force Base in San Antonio – just two months after Defense Secretary Pete Hegseth dropped a vaccination mandate for the military.
At the basic military training wing, hundreds of trainees, who are already more likely to get sick due to lower immune systems from physical, psychological and environmental stress, were exposed to the flu over the last three weeks, leading to a “localized” outbreak, ABC News reported last week.
As of June 19, there had been 222 cases of the flu, Rep. Joaquin Castro, who represents the San Antonio area, said, while four had been hospitalized. It’s a sharp increase from 159 cases and two hospitalizations a week earlier, ABC reports.
It occurred after Hegseth dropped flu vaccine requirements for members of the military in April. In a video, the defense secretary described the vaccine requirement as “irrational” and part of “absurd, overreaching mandates.”
Yet, in the weeks after the policy took effect, only 40 percent of Air Force trainees opted in to be vaccinated, the New York Times reported. The rate was previously close to 100 percent, ABC News reports.
Pentagon Spokesperson Sean Parnell said in a statement that Hegseth’s new vaccine guidance had allowed for exemptions. The Under Secretary of War for Personnel and Readiness had granted exemptions to the Army, Navy, Air Force, National Security Agency, and the Defense Health Agency.
“The decisions were based upon thorough risk assessments and are designed to maximize operational readiness, lethality, and force generation, while safeguarding at-risk populations,” Parnell said. “The Department remains committed to the health and readiness of our warfighters and civilian personnel.”
With the exception, the Air Force has the goal of vaccinating all recruits in this class and all the new recruits arriving at the base, ABC reports.
Historically, trainees are the most vulnerable to respiratory disease due to their weakened immune system while training, the Defense Health Agency wrote in an August 2025 monthly medical report. Studies show that recruits have a higher incidence of flu-like illness compared to non-recruits.
In addition to the high physical and mental stress, new recruits sleep in bunk beds in open bays and share meals at large communal tables, the New York Times reported.
Some had warned that Hegseth’s new vaccine directive could be detrimental to military readiness.
“After Secretary Hegseth scrapped the military’s flu vaccine mandate, it was only a matter of time before an outbreak occurred. It was a reckless decision that put troops in harm’s way and undermined our military readiness,” Castro wrote on X last week after news of the outbreak emerged.
A spokesperson for the Air Force said in a statement that the 37th Training Wing has been in close coordination with the 59th Medical Wing to manage the localized flu outbreak, including isolating and treating symptomatic trainees to reduce exposure.
“Medical personnel are also monitoring trainees who were in close contact with sick members in case they become symptomatic. Symptomatic trainees are receiving the appropriate care with antiviral medications such as Tamiflu. Once they are cleared by medical professionals they will return to training,” the Air Force spokesperson said.
