Both are not viruses
It is both a vulnerability which can be exploited on the x86 platform, mainly on intel.
What you need to do instead is to make sure you're OS is patched for meltdown and bios updated(provided your board has one) for the spectre variant.
If your on AMD specifically ryzen I would not worry too much. While AMD is planning to release an "optional firmware updates" for its processors to protect against the Spectre variants of CPU exploits, I would personally hold off as bugs,slowdowns and such might be a side effect of doing so as AMD is near zero risk of being exploited until these firmwares are thoroughly tested
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You might also like to update your GPU driver if you're on on NVIDIA as they recently had an update to their drivers and is pushing these updates to "strengthen against spectre further".
Also your software, programs and apps like browsers if they have a patch for these vulnerability. Google and read
YMMV