“The flu outbreak… is getting worse”: Texas Democrat reveals alarming jump in cases as military reverses course on mandatory flu vaccines
Texas – Texas Rep. Joaquin Castro says a growing flu outbreak at Joint Base San Antonio-Lackland has taken another troubling turn, reporting that confirmed infections have climbed dramatically as the U.S. military moves back toward mandatory flu vaccinations for recruits after relaxing the policy just months ago.
The Texas Democrat shared the latest figures on June 24, saying his office received updated information directly from the Air Force showing the outbreak had continued to expand.
“The Air Force confirmed with my office that the flu outbreak at the Air Force Lackland Base in San Antonio is getting worse,” Castro wrote on X. “There are now 275 confirmed cases.”
The Air Force confirmed with my office that the flu outbreak at the Air Force Lackland Base in San Antonio is getting worse. There are now 275 confirmed cases. https://t.co/so3UENGgn7
— Joaquin Castro (@JoaquinCastrotx) June 24, 2026
His announcement came only hours after ABC News reported, citing sources familiar with the situation, that the number of infected trainees had continued to rise over recent days. Castro’s update represented another significant increase, with more than 50 additional cases reported in roughly a single day compared with the previous publicly known figures.
Military reinstates mandatory flu shots for recruits
The outbreak has grown steadily over the past several weeks. By June 23, at least 222 recruits had tested positive for influenza, while four had been hospitalized. Just one week earlier, officials had reported 159 infections and two hospitalizations, illustrating how rapidly the virus has spread through the training population.
As infections continued to climb, the military changed course on its vaccination policy.
Although Defense Secretary Pete Hegseth announced in April that flu shots would become optional across the armed forces, the Army, Navy and Air Force have now received exceptions allowing them to once again require influenza vaccinations for basic trainees.
Pentagon spokesperson Sean Parnell confirmed that all three military branches have reinstated the requirement for recruits entering basic training.
According to one source familiar with the Air Force’s response, officials now intend to vaccinate every recruit currently undergoing training at Lackland as well as every new trainee arriving at the installation. The Army is also preparing to broaden mandatory vaccination requirements in the coming weeks for several additional groups, including personnel deploying overseas, first responders, health care workers, child care employees, prison staff and soldiers participating in major training exercises.
The policy shift comes after vaccination rates among new Air Force recruits fell sharply.
According to ABC News sources, only about 40 percent of incoming trainees at Joint Base San Antonio had received flu vaccinations when the outbreak began in early June. Under the previous long-standing policy, vaccination rates had been nearly universal.
When announcing the policy change in April, Hegseth defended making the vaccine optional. “Our new policy is simple: If you, an American warrior entrusted to defend this nation, believe that the flu vaccine is in your best interest, then you are free to take it; you should. But we will not force you,” Hegseth said.
The War Department is once again restoring freedom to our Joint Force.
We are discarding the mandatory flu vaccine requirement, effective immediately. pic.twitter.com/9K5W8g0NsD
— Secretary of War Pete Hegseth (@SecWar) April 21, 2026
That decision has since drawn criticism from both sides of the political aisle.
Sen. Roger Wicker, the Republican chairman of the Senate Armed Services Committee, called ending the mandatory vaccination requirement a “mistake.” “When I was on active duty and a reservist, I dutifully took my flu shot every year,” Wicker told reporters. “And as a whole, it made for a healthier” armed forces.
Close living conditions fuel rapid spread
Health officials say the environment of military basic training creates ideal conditions for contagious illnesses to move quickly through a recruit population.
Trainees sleep in crowded open dormitories, share bathroom and shower facilities, and spend nearly every hour of the day together during drills, classroom instruction and inspections. Combined with demanding physical activity, limited sleep and elevated stress, those conditions can weaken immune systems while making it easier for viruses to spread from person to person.
Military health experts have long recognized those risks. During World War I, the 1918 Spanish flu pandemic claimed more American military lives than combat itself, a reminder often cited when discussing disease prevention in military training environments.
The outbreak has also drawn attention because it is occurring well outside the normal flu season, which usually peaks between October and spring.
Dr. Stephen Ramirez of Stone Oak Family Practice in San Antonio said this year’s influenza pattern has behaved differently. “It’s been a little unusual,” Ramirez said. “Usually, we get a spike of the flu and then it tends to go down. This year’s flu has a little bit of staying power.”
Investigation continues into recruit’s death
The outbreak has unfolded alongside the death of Air Force recruit Keon McDaniel, whose case remains under investigation.
McDaniel, assigned to the 737th Training Support Squadron, suffered a medical emergency on June 12 during his sixth week of basic training. He later died on June 16 at Brooke Army Medical Center.
The Air Force has emphasized that officials have not established any connection between his death and the influenza outbreak. A comprehensive medical review remains underway to determine the cause.
Meanwhile, the 37th Training Wing, which trains more than 36,000 recruits every year at Lackland, says it continues working closely with the 59th Medical Wing to contain the outbreak.
Officials said “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.” In addition to isolating sick recruits, those who become ill are being treated with antiviral medications such as Tamiflu, while dormitories, dining facilities and other shared spaces are undergoing enhanced cleaning.
Despite Castro’s latest figures and multiple media reports, the Air Force has continued declining to verify specific case numbers publicly. Asked about the updated total, an Air Force spokesperson told The Hill only that medical personnel continue to “monitor and evaluate the situation,” without confirming or disputing the reported number of infections.
