@mfennvt I don't have the references at my fingertips, but I remember seeing earlier in the pandemic that "mixing and matching" your vaccines was more effective than sticking with the same brand. I don't know if that's held up over the years, but I still try to vary the brand I get. Practically, I almost always get Pfizer or Moderna because they are what's available in my area, but in the couple times I've been able to get Novavax, the side effects were WAY better for me.