Have read that the mmr vaccine may help with covid 19. i had a booster 2 or 3 yrs ago. could this possibly help if i was to get covid?

Wouldn't count on it: Any such information wherever you found it is little more than speculation at this point. The viruses involved are quite different & antibodies triggered by a vaccine are selective to the type of stimulus it responds to (here MMR). Much like puzzle pieces if it is not the same puzzle, a piece may come close but not actually fit.

Theory: Theory: MMR vaccine may protect from severe COVID 19 through myeloid-derived suppressor cells, (immune cells from bone marrow). This is based on stats: areas where MMR is routinely given have lower COVID-19 death rates. Many sailors (all had previous MMR vaccine) on the U.S.S. Roosevelt only had mild sx’s. REF: https://www.medicalnewstoday.com/articles/mmr-vaccine-could-prevent-worst-symptoms-of