An influenza outbreak at Lackland Air Force Base in Texas has grown to 275 confirmed cases as of Wednesday, up from 160 the previous week, according to figures provided by the Air Force to Rep. Joaquin Castro's office.
The surge follows Defense Secretary Pete Hegseth's April decision to end the military's mandatory flu vaccine requirement for service members. Four people have been hospitalized as of Tuesday, ABC News reported. One recruit also died on June 16, though that death remains under investigation and officials have not confirmed whether it is connected to the outbreak.
The 37th Training Wing at Joint Base San Antonio has been hardest hit by the spread. More than 36,000 recruits pass through the base annually, making it one of the military's largest training installations.
What the Right Is Saying
Hegseth defended his April decision as giving troops "medical autonomy" and "freedom to express their religious convictions." He characterized the previous flu shot requirement, in place since 1945, as an "absurd" and "overreaching" mandate that weakened the country's warfighting capabilities.
The defense secretary argued at the time that the decision to receive a vaccine "posed no threat to our military readiness." Supporters of the policy change have echoed this framing, saying service members should have the same healthcare choices as civilian counterparts.
Conservative commentators have noted that the services retain broad discretion in implementing Pentagon policy and are responding through their own chain of command rather than reversing the secretary's directive at the departmental level.
What the Left Is Saying
Rep. Joaquin Castro (D-Texas) called Hegseth's April decision to remove the flu vaccine mandate "reckless" and said it set the stage for an outbreak at Lackland. In a statement, Castro emphasized that the base trains thousands of young service members each year and described the spread as preventable.
The congressman has requested regular briefings from the Air Force on case counts and the health of those hospitalized. His office confirmed receiving updates showing the case total rose by 115 in one week.
Public health advocates aligned with Democrats have argued that mandatory vaccination policies exist to protect both individual service members and unit readiness. They note that flu outbreaks can incapacitate entire squadrons, potentially affecting training timelines and deployment preparations.
What the Numbers Show
275: Confirmed flu cases at Lackland as of Wednesday, up from 160 the previous week. The Air Force confirmed these figures to Rep. Castro's office.
4: Hospitalizations reported as of Tuesday by ABC News.
1: Recruit death on June 16 under investigation. Officials have not determined whether it is connected to the outbreak.
36,000+: Annual recruits who pass through Lackland, according to base data.
1945: Year the military first implemented mandatory flu vaccination for service members before Hegseth's April reversal.
The Army, Navy and Air Force are now requiring flu shots for basic trainees again. The Army is also exploring extending that requirement to deploying troops, first responders, childcare workers, healthcare personnel, prison staff, and participants in large-scale training exercises, according to ABC News reporting.
The Bottom Line
Military services have moved to reinstate flu vaccine requirements for basic trainees despite Hegseth's broader policy change, signaling concern about the outbreak's impact on training operations. The death of a recruit remains under investigation, and officials have not confirmed whether it is related to the flu spread.
Castro and other Democratic lawmakers are likely to press for additional information as case counts continue to rise. The situation may intensify scrutiny of the Defense Department's vaccination policy direction heading into the summer months when respiratory illnesses typically decline but have persisted at Lackland.