Good luck!
The book baby medical school- vaccines is also awesome, it explains what a vaccine is and does, and why it's important in toddler appropriate language! (Great if you have a why kid)
https://www.amazon.ca/Baby-Medical-School-Cara-Florance/dp/1492694002
DM me your home address, and I'll send you a board book that can help further your medical knowledge. As you can see from the preview, it's right in your Lexile range.
https://www.amazon.com/Baby-Medical-School-Vaccines-University/dp/1492694002
Baby Medical School has a vaccines book. https://www.amazon.com/Baby-Medical-School-Vaccines-University/dp/1492694002