The new Quadrivalent vaccine to protect against four flu viruses is in short supply.
The Minnesota Department of Health says a vast majority of clinics use Trivalent to fight the bug.
But the CDC doesn't recommend one vaccine over the other because the important medication in each shot is present in both versions.
Copyright 2016 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.