There is no software solution. You need a hardware approach. A concrete bunker with two foot thick walls and roof, independent power generation, hydroponic greenhouse and high level air filtration system should work.
You need to disconnect your computer from the internet BEFORE it becomes infected, and keep it disconnected permanently. There is no AV software that can do anything about Covid-19.
You've got to go a cut above the normal recognized brands. I'm sure the Russians have a quality, legit product that I can't pronounce, but it's exclusive. They'll e-mail you if you qualify, and probably require cryptocurrency payment in advance for their services. I hear they're so good, they have webcam footage of everyone who looks at inappropriate content, even if they don't have webcams.
Note to the completely ignorant: DON'T actually do this.