The Air Force has discharged 40 service members and is now preparing to address the thousands of others who failed to get a coronavirus vaccination before the Nov. 1 deadline officials imposed, becoming the first branch to execute what military leaders consider an essential protective measure but one that critics believe will undermine America’s ability to defend itself.

“Now that the deadline has passed, there’s a clear line to begin holding people accountable,” Air Force spokeswoman Ann Stefanek tells U.S. News.

The population of discharged airmen and “guardians” from the Space Force – the military’s newest branch, which falls under the Department of the Air Force – has been relatively new trainees. Almost two dozen of them were in basic training when they refused to take the vaccine, and the remaining 17 were undergoing technical training where new enlistees learn their military specialties. Commanders at those schools have a different standard of due process than those overseeing airmen and guardians who have been in the service for years.