I was required to get a DTaP vaccine in college (in another state, mind you) because I couldn't prove that I had gotten one as an adolescent. I had gotten one, but I'd lost the record.
No, you’ve misunderstood: I lost the records between high school. I have multiple friends who were required to get their MMR vaccines again in high school because they couldn’t find their records.
I was required to get a DTaP vaccine in college (in another state, mind you) because I couldn't prove that I had gotten one as an adolescent. I had gotten one, but I'd lost the record.