@overholt Yes, Yay Science! I’m 71 and got another MMR booster last year after I found out I had no immunity to measles or rubella, but I had to really insist on a titer test with Kaiser since they required one. One local pharmacy said they would give (sell) me the vax if Kaiser wouldn’t give me one - and I was interested to read someone mention that these local pharmacy policies may have changed (wouldn't be surprised). I had no IDEA that a vax could “wear out” until in the course of Kaiser chasing down an alarming lab result (now resolved), I noticed that my Hep B vax no longer gave me immunity, so I demanded a new one and I immediately started to worry about the others, especially measles. Sure enough... My local extended family had terrible experiences with polio, rubella, and whooping cough back in the day, which of course I brought up for emphasis. So I’m glad that I acted fast and didn’t suffer much indecision/nagging fear, who needs more of that...