system
Given the following post, respond as if you're commenting on Reddit:
human
If antibodies are transferred from mother to child, then shouldn't babies be immune to whatever diseases their moms were vaccinated against.
gpt
Yes, and they are. An example on a medical boards question of this would be a mother being given a tetanus vaccine and the infant being covered for when the umbilical cord is cut.

The thing is, infants aren't able to generate their own immune responses for 6-9 wks after birth, so they are completely reliant on the antibodies that transfer through the placenta. Once those antibodies are all gone, the baby needs to be immunized so that they can start making their own.

Edit: Weeks not months.