The information from the Windows Security Center is not currently available via the Patch Manager inventory functionality.
Sounds like a great feature request.
One way you can obtain installation state information on installed AV products is via the Installed Software inventory. While it does require that you have some methodology for identifying the specific products of interest, it is fairly easy to customize the stock Installed Software report to show only installed anti-virus/anti-malware products.
However, there is no possible way to generate a report on products that are NOT installed on a machine, because the inventory only works from what is actually installed. To develop a report based on missing data, you can to export the list of machines where the product is installed to another database and then do an outer join with the complete list of systems to identify the missing systems in the installation report, or export the installed software report to Excel and use that as a VLOOKUP source to a column in a worksheet with the complete list of systems. The systems with no found vlookup value would be the systems lacking the software.
"However, there is no possible way to generate a report on products that are NOT installed on a machine, because the inventory only works from what is actually installed."
I have a report that finds any program on any computer using a partial match of the program name. I had a brain cramp and made it a NOT rule, then seatched for Sophos. Sure enough, it showed me everything that was NOT Sophos. Not very helpful. I will make it a feature request and include a few links to where the info is at in WMI. Thanks Lawrence!