The authors didn't care enough to write a story.
What? This feels like it should have a message other than the explicit one. It feels like it should go somewhere as a story, but it doesn't. There's no story here. It's just a framing device for a lecture. Literally, in the middle of the book, the story stops and somebody gives a lecture. It details the lecture that is given. They didn't even try to make a story out of the message. This is not going to hold anyone's attention. It didn't hold my attention, and it's certainly not going to hold a child's attention.
The kids are going to school. Papa is a parent helper that day at school. Everybody is sneezing, coughing, and sick. Dr. Gert Grizzly gives a lecture, and it shows every slide of the lecture. "Germs are bad. Wash your hands. Don't cough and sneeze on people." And then all the kids go and wash their hands. And the parents don't wash their hands. Then they come home, and Papa is sick because he's coming down with a cold. Which he was at the beginning of the book, because that's when he started sneezing. There's no consequence for him not washing his hands.
The best part: "Now here's a friend of mine, Jerry the Germ, with a special message." (The image shows an anthropomorphic germ holding a sign saying, "Come clean for school!") "The cubs all laughed and clapped, and the slide show was over." What are they laughing and clapping about?! That wasn't remotely funny! It was a boring lecture! I guess all the cubs are idiots.