WASHINGTON (AP) — The Pentagon said Wednesday that boot camps for all the military services are once again requiring the flu vaccination for all recruits after Defense Secretary Pete Hegseth made the shot optional for the military at the end of April. The development, confirmed to The Associated Press by a Pentagon official, comes amid a growing, weekslong, flu outbreak at the U.S. Air Force’s boot camp at Lackland Air Force Base that has sickened nearly 300 people. However, the official, who