An influenza outbreak has reportedly sickened more than 150 recruits in training at Lackland air force base in San Antonio, Texas.

The outbreak comes just weeks after the defense secretary, Pete Hegseth, ended mandatory flu vaccination for the military, citing the need for bodily autonomy for servicemembers.

“We’re seizing this moment to discard any absurd overreaching mandates that only weaken our war fighting capabilities,” said Hegseth in an April social media video. “In this case that includes the universal flu vaccine and the mandate behind it.”

“Your body, your faith and your convictions are not negotiable,” said Hegseth.

At least 159 recruits have fallen ill, according to the New York Times and ABC News. After Hegseth made influenza shots optional, only about 40% of recruits opted to get vaccinated, air force officials told the New York Times.

About 46% of adults were vaccinated against influenza in the 2025-26 cold season, according to the Centers for Disease Control and Prevention (CDC).

Lackland is located inside Joint Base San Antonio, a 70,000-member installation sometimes called Military City. Recruits at Lackland live in communal settings, eating together and sleeping in dormitories. Such settings are known to be vulnerable to outbreaks of airborne illness.

It is not clear whether the recent death of a basic military trainee was related to the outbreak. Keon McDaniel died on 16 June after experiencing a “medical emergency”. The cause is under investigation, according to an air force press release.

Air force officials said recruits at Lackland have been ordered to be vaccinated against the flu as part of containment efforts, according to the Times.

A spokesperson for the Pentagon directed the Guardian to the air force press office.

The air force press office did not immediately respond.