Will Falconer, DVM Moderator
Nice work, Rosie. Thanks for sharing this with us.
I would add only one refinement to your newfound understanding. The immunologists with nothing to sell tell us that titer you find at first means immunity is there, regardless of whether that value is high or low. It's just got to show up to know they've "converted," and will carry immunity forward, likely for life.
Thanks again, and all the best with your Vital Pack of myriad ages.