Explanation
Firewalls with an active WildFire license can retrieve the latest WildFire signatures every five minutes. If you do not have a WildFire subscription, signatures are made available within 24-48 hours as part of the antivirus update for firewalls with an active Threat Prevention license.
https://docs.paloaltonetworks.com/wildfire/9-0/wildfire-admin/wildfire-overview/wildfire-concepts/wildfire-sign