I, too, recommend Windows Security and it's all I recommend these days to clients, whether they're screen reader users or not.

Look at the most recent testing results from the following antivirus/security testing labs, along with the historical results from the past several years if you want to see how Windows Security/Defender has been performing.  Windows Security has been solidly in the top 10, often top 5, and frequently beats out several well-known competitors that one must pay for.

AV Test

AV Comparatives

SE Labs  (Reports Page)

MRG Effitas  (360 Protection Testing Category)

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Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042  

It is better to be hated for what you are than to be loved for what you are not.

           ~ André Gide