Dropping the Flu Vaccine Requirement Puts U.S. Military Readiness at Risk
On Tuesday, Secretary of Defense Pete Hegseth announced that the men and women who defend our nation will be able to choose whether to be protected from the flu. In his video statement, he said that service members will no longer be required to get the annual influenza vaccine because flu causes “no threat to our military readiness.”
Unfortunately, this is untrue. During the 1918 influenza pandemic, more than 20,000 U.S. service members died and hundreds of thousands were hospitalized. People of military age were among those with the highest death rates during that outbreak, impacting not only their health, but the U.S. economy and military readiness. Historians report that up to 20{7729880385ace00763d744956af66a2dd6156639dea227c3bc209fe61f7ca481} of U.S. service members became ill.
A History of Flu Vaccination in the U.S. Military
As a result of the 1918 pandemic, the U.S. military began pursuing a flu vaccine to ensure that, in the future, our nation’s defenders would be protected from this threat. During World War II, the U.S. military pioneered the first flu vaccine, which protected those in uniform from serious illness or death. It has required flu vaccinations for all men and women who serve since the 1950s.
The military experience also helped the medical community learn that some viruses, like the flu, change frequently, requiring regular updates to vaccines. This knowledge has been crucial in protecting service members from the flu and other infectious diseases.
The Risks of Not Requiring Flu Vaccinations
Flu is easily spread when people are in close contact. And military service requires operating in many places where it’s easy to spread viruses like the flu, including ships, tents in deployed locations, tanks, submarines, barracks, training facilities, and planes with multiple crew members and/or passengers.
Even more unfortunately, asking people who develop flu-like symptoms to isolate is insufficient because those who are infected with the flu can spread it a day prior to symptom onset. Furthermore, some of those infected with the flu have very mild or no symptoms.
During the 2023-24 flu season, for every 100,000 people over 65 infected with the flu, 32 died and 400 were hospitalized; similarly, for every 100,000 adults of military age, two died and 65 were hospitalized. Asserting that flu poses no risk is untrue.
Historical Precedents for Vaccination Requirements
Our nation’s best military leaders have long recognized the risks infectious diseases can present. Gen. George Washington, when he commanded the Continental Army during our War of Independence, directed that everyone in uniform be inoculated against smallpox, because it was significantly degrading military readiness.
During World War II, Gen. Douglas MacArthur reportedly highlighted that the war would last longer because for every division facing the enemy, another was hospitalized and a third was convalescing from infectious diseases.
In 1999, the military stopped vaccinating troops to protect them from adenovirus infections. As a result, 13,000-15,000 troops in training became ill every year, of whom over 1,000 required hospitalization. Even more unfortunately, eight men and women who volunteered to defend our nation died of adenovirus infections before the vaccine requirement was reinstituted in 2011; since then, there have been no deaths due to adenovirus infections among military personnel.
National Security Implications
Political leaders have also recognized the national security risks posed by naturally occurring, accidental, and deliberate biological threats. President Trump, in his 2018 National Biodefense Strategy, explicitly identified influenza as a significant biological threat.
More recently, now-Secretary of State Marco Rubio, in an April 2025 assessment of compliance with the Biological Weapons Convention, noted that Russia and North Korea maintain an offensive bioweapons program and that the “United States does not have sufficient information to determine whether China has eliminated its assessed historical biological warfare program.” Hegseth’s decision unfortunately may have given potential adversaries a new vulnerability to exploit.
Protecting Military Personnel from Preventable Illness
The U.S. military must be available every day, anywhere to defend our nation. To do so, the military has developed numerous measures to protect military personnel from preventable illness or injury. Body armor, for example, can’t prevent you from being shot, but it does a great job of preventing almost all of those who are shot from dying.
Similarly, flu vaccines are not a force shield that protects anyone from any infection, but they are very good at protecting those who become infected from becoming seriously ill and from dying.
Over the course of 37 years of military service, I saw firsthand in peacetime and in combat the incredible dedication of men and women who volunteer to defend our nation. They deserve the truth about the risks from flu and the truth about the benefits from the flu vaccine, not political platitudes.
Maj. Gen. (ret.) Paul Friedrichs, M.D., is a retired military medical officer whose last job in uniform was in the Pentagon as the senior medical adviser to the Joint Chiefs. He then served as the senior director for global health security and biodefense on the National Security Council.
- The flu vaccine has been required for all U.S. military personnel since the 1950s.
- The flu can spread quickly in close quarters, such as on ships, in barracks, and in training facilities.
- Even mild cases of the flu can still be contagious and spread to others.
- The flu vaccine is not 100{7729880385ace00763d744956af66a2dd6156639dea227c3bc209fe61f7ca481} effective, but it can significantly reduce the risk of serious illness and death.
- The U.S. military has a long history of requiring vaccinations to protect personnel from infectious diseases.
In conclusion, dropping the flu vaccine requirement puts U.S. military readiness at risk. The flu is a serious threat to military personnel, and the vaccine is a crucial tool in protecting them from illness and death. The decision to make the flu vaccine optional may have significant consequences for the health and readiness of our military personnel.