The Air Force has re-implemented a flu shot requirement for trainees after more than 200 fell ill due to an outbreak at the Lackland Air Force Base in San Antonio " just two months after Defense Secretary Pete Hegseth dropped a vaccination mandate for the military. At the basic military training wing, hundreds of trainees, who are already more likely to get sick due to lower immune systems from physical, psychological and environmental stress, were exposed to the flu over the last three weeks, leading to a "localized" outbreak, ABC News reported last week. As of June 19, there had been 222 cases of the flu, Rep. Joaquin Castro, who represents the San Antonio area, said, while four had been hospitalized. It's a sharp increase from 159 cases and two hospitalizations a week earlier, ABC reports. It occurred after Hegseth dropped flu vaccine requirements for members of the military in April.