U.S. airmen and Air Force trainees have fallen ill after a flu outbreak at Lackland Air Force Base in Texas, according to a spokesperson for the military branch. The number of sickened troops could be over 200, according to a source at the base.

The outbreak comes less than two months after Secretary of Defense Pete Hegseth ended the requirement for U.S. troops to receive an annual flu vaccine. In an April video announcement, Hegseth called the mandate “absurd” and “overreaching.”

“Under the disastrous Biden administration, this Pentagon waged an unrelenting war on our warriors on many fronts, including when it came to denying them simple medical autonomy and the freedom to express their religious convictions,” Hegseth said.

Lackland is where Air Force enlistees go for basic military training. The sprawling facility cycles through tens of thousands of recruits every year.

The New York Times was first to report the news of the outbreak.

In the wake of the outbreak, the Air Force requested an exemption to Hegseth’s policy that allowed them to mandate flu vaccines at the base, according to a second person familiar with the details of the response.

The base has since started vaccinating people.

In a statement, an Air Force spokesperson described the outbreak as “localized” to the base’s basic training wing.

“Medical professionals and public health officials have implemented mitigation measures to isolate and treat symptomatic trainees to reduce further exposure and continue to monitor the situation,” the spokesperson said.

“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,” they said.

In a separate statement, Pentagon spokesman Sean Parnell said Hegseth granted exemptions to his vaccine policy for all military departments to keep up with “critical operational realities.”

“The Secretary of War recently issued updated guidance on the influenza vaccination, stating that this vaccination is voluntary for all Active and Reserve Component Service members and Department of War civilian personnel, and directing the Under Secretary of War for Personnel and Readiness to consolidate all requested exceptions to the policy,” Parnell said.

“The Department remains committed to the health and readiness of our warfighters and civilian personnel,” Parnell added.