Why haven't I had covid?

[C_T_Russell]

I was also reading a study that people who have had the measles vaccine have had less covid symptoms, hence why some younger people have not had it (or at least knowingly)
The hypothesis goes that measles and covid share a similar protien that the vaccine produces, hence some shared immunity.

But in general i think its inevitable that not everybody will get covid, but alot of people I know have had it, but one friend of mine only just caught it last week from his workmate.