system
Given the following post, respond as if you're commenting on Reddit:
human
If I went back in time 2000 years would my immune system be any less effective?

I know that microbes can evolve fairly quickly so would 2000 years of change be long enough for our immune systems to not recognize the germs?
gpt
it would probably be effective for some microbes/viruses but unlikely to be as effective as it is today. 

Even going back a few decades and you had small pox, a few more and HIV did not exist and every winter bring new flu strains.Things change fast.

Don't forget geography ; Traveling around the world today, each new continent and country brings its own immunological challenges, ( hence travelers diahorrea ),  so its a safe bet that things were very different 2000 years ago.