There's quite a bit of documentation on the Veeam site for protecting the VCSA Appliance:
1.) Veeam KB 2328
2.) Veeam Technical Whitepaper (August 2017)
In short, it is possible and really very easy. I am going to assume you're using the local Platform Services Controller (PSC) and not an External PSC. Create a Veeam Backup job with your vCenter server with application-aware image processing not enabled, instead turn on VMware Tools Quiesence.
Hope this helps.