A flu outbreak at the Air Force Basic Training Center in San Antonio is worsening, according to two sources familiar with the situation.
As of Wednesday, the number of cumulative cases linked to the flu outbreak at Lackland Air Force Base, part of Joint Base San Antonio, had reached 275, up from 222 cases reported Tuesday, according to people familiar with the situation.
As of Tuesday, four people were hospitalized, two people familiar with the situation previously told ABC News.
This marks a sharp increase from the 159 cases and two hospitalizations reported last week. The death of one recruit is being investigated, although it is not yet clear whether it is related to the outbreak, the sources said.
The outbreak comes just two months after Defense Secretary Pete Hegseth made the annual flu shot optional for military personnel, reversing a military requirement that dates back to 1945, contrary to longstanding public health directives.
โOur new policy is simple: If you, the American warrior charged with protecting this nation, believe that the flu vaccine is in your best interest, then you can take it; you have to do it. But we wonโt force you,โ Hegseth said in April.
However, those services have already been granted exceptions to Hegseth’s policy, according to Pentagon spokesman Sean Parnell in a statement provided to ABC News. As part of these exceptions to the policy, the Army, Navy and Air Force are again requiring flu shots for basic trainees, officials said.
In the Air Force, only about 40% of new trainees at Joint Base San Antonio had received a flu shot when the outbreak began in early June, according to two Air Force sources.
A front view of the entrance gate to the Chapman Training Annex in San Antonio, Texas on August 17, 2024. Chapman’s training application is part of Joint Base San Antonio.
Carlos Kosienski/Sipa USA via Reuters
But with the new exception to the policy, the Air Force’s goal is to vaccinate all recruits in this recruit class and will vaccinate all new recruits arriving on base, according to one source.
What’s more, the Army is preparing to expand the requirement in the coming weeks to troops stationed overseas, first responders, child care workers, medical personnel, prison staff and soldiers participating in certain large-scale exercises, according to a service spokesman.
While the Pentagon sets policy for the military, the services and their commanders often retain broad authority to adjust how those directives are carried out, whether to address security concerns or work around bureaucratic obstacles.
During basic training, troops live in close quarters, sleeping in tightly packed pods, sharing showers and spending much of the day within arm’s length of each other undergoing drills, instructions and inspections.
In such conditions, the disease can spread quickly once one trainee falls ill. Troops are also constantly stressed and exhausted, which can leave the immune system vulnerable.
Keon McDaniel, the Air Force recruit who died, was in his sixth week of basic training when he suffered a medical emergency on June 12, according to the Air Force. Recruits undergo a medical examination before they can enlist, but the process depends largely on medical history and a relatively limited clinical examination.
He was taken to Brooke Army Medical Center, where he later died. According to the Air Force, the cause of the medical emergency is currently under investigation and a full medical examination is being conducted to determine the facts.
The Air Force did not immediately respond to ABC News’ request for comment when asked about details of the scope of the flu outbreak.
In response to the outbreak, some U.S. officials, including Rep. Joaquin Castro, whose district covers about half of San Antonio, including Lackland Air Force Base, criticized Hegseth’s policy of ending mandatory vaccinations.
โAfter Secretary Hegseth lifted the military’s flu vaccine mandate, it was only a matter of time before an outbreak occurred,โ he wrote in a post on X last week. โThis was a reckless decision that put troops at risk and undermined our military readiness.โ
In another post on X, Castro confirmed that the Air Force told his office that there had been 222 cases of the flu on the base. “We need answers,” he added.