Yes, you can transfer from Virgin Mobile prepaid account.
Some people recommend first getting a temporary new Public Mobile number first. Try PM service for a while and if satisfied, then port your VM mobile number afterwards.
@jaxie3- being virgin prepaid pease port with a minimum 3- 4 days before your virgin renewal/expiry date. This is to ensure that should you have a porting problem your virgin line does not become inactive since you need an active line to port.