The world’s top infectious disease experts say the U.S. government has a responsibility to provide preventative care such as flu vaccines to migrants immediately after they are taken into custody, but the federal agency involved says disease prevention is not its job.

“The introduction of the Influenza vaccine and other vaccines … is something we need to start thinking about from day one when these people come into our responsibility,” Dr. William Schaffner, an infectious diseases specialist at Vanderbilt University Medical Center in Nashville, told the Washington Examiner.