NEW YORK (AP) — At least 600 employees of the Centers for Disease Control and Prevention are receiving permanent termination notices in the wake of a recent court decision that protected some CDC employees from layoffs but not others.

The notices went out this week and many people have not yet received them, according to the American Federation of Government Employees, which represents more than 2,000 dues-paying members at CDC.

The U.S. Department of Health and Human Services on Wednesday did not offer details on the layoffs and referred an AP reporter to a March statement that said restructuring and downsizing were intended to make health agencies more responsive and efficient.

AFGE officials said they are aware of at least 600 CDC employees being cut.

But “due to a staggering lack of transparency from HHS,” the union hasn’t received formal notices of who is being laid off,” the federation said in a statement on Wednesday.

The permanent cuts include about 100 people who worked in violence prevention. Some employees noted those cuts come less than two weeks after a man fired at least 180 bullets into the CDC’s campus and killed a police officer.