I mean the best ways to avoid URIs is the covid precautions we’ve all been hearing about the last two years: Mask, social distance, wash your hands (like for real, 30 seconds of scrubbing) or hand sanitizer when you can’t. They did studies on healthcare workers during covid and wearing glasses was surprisingly effective (turns out viruses can enter your body through your eyes, so glasses help prevent that) so you could try wearing clear glasses in public if you don’t have prescription glasses.
The other piece being eating well to fuel your recovery.
Another option is do do less ME work. I found that 2x per week was too much for me and I got burnt out really quickly so I dropped to 1x per week.