Hegseth just ended a flu vaccine rule that’s been in place since the 1950s, and health experts say it puts troops at direct risk

Defense Secretary Pete Hegseth has ended the U.S. military’s mandatory annual flu vaccine requirement, effective immediately. As detailed by Al Jazeera, the policy had been in place since the 1950s and was historically used to keep hospitalization rates among service members below national averages.

Hegseth announced the change in a video posted to X, framing it as a matter of personal liberty. “The War Department is once again restoring freedom to our Joint Force,” he said. He added that requiring the flu vaccine for every service member “in every circumstance at all times is just overly broad and not rational.”

The Defense Secretary cited medical autonomy and religious freedom as the basis for the decision, arguing the mandate weakened warfighting capabilities. Under the new directive, vaccination remains optional. “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. Individual military branches have a 15-day window to request that the requirement be reinstated if they deem it necessary for their operations.

The mandate has a long history the Pentagon is now walking away from

The flu vaccine program has been a fixture of military health policy for decades, with the Department of Defense typically aiming to vaccinate more than 90 percent of active-duty personnel each year. An October 2025 Armed Forces Health Surveillance Division report credited the program with keeping service member hospitalization rates well below national averages. The report flagged close-quarters environments like recruit stations as particularly high-risk, where flu hospitalization rates among recruits between 2010 and 2014 reached 70 per 100,000, compared to 7.4 per 100,000 across the broader military.

Health experts have long pointed to the flu’s potential severity. Medical historians note that the 1918 flu strain infected more than a quarter of the world’s population and killed 50 million people, including 675,000 Americans. More than 45,000 U.S. service members died from the virus during that period, a toll some historians link to troop deployments for World War I.

The effectiveness of the annual flu shot does vary. Preliminary data for this year’s vaccine showed it was 25 to 30 percent effective in preventing adults from needing to see a doctor, below the 40 to 60 percent threshold generally considered effective. The current administration has shown a broader willingness to pull back on vaccine guidance, amid a Palantir-backed push for universal national military service that has reignited debates about federal control over the armed forces.

This decision follows the military’s 2023 rollback of its COVID-19 vaccine mandate, which came after Congress passed legislation in 2022. During the enforcement of the 2021 COVID mandate, more than 8,400 service members were discharged for refusing the shot, a period Hegseth has described as an era of betrayal. Earlier this year, the CDC under the Trump administration also dropped its recommendation that children receive the annual flu shot, and a federal judge has temporarily blocked parts of that broader effort, leaving some adult recommendations in legal limbo. Amid separate Trump administration policy changes moving through federal agencies, the individual military branches now have 15 days to decide whether to request retention of the flu vaccine requirement for their personnel.