Answer:
a. childhood vaccine
Step-by-step explanation:
"DTaP" is a vaccine that is being administered among young children, specifically those who are younger than 7 years old. This vaccine prevents the child from getting Diptheria, Tetanus and Pertussis. These diseases are dangerous in nature and could cause death, that is why it is very important to get an immunization against them. Local communities give this vaccine for free, so parents don't need to worry on it.
The booster for this is called "Tdap." This assures a lasting protection from the three diseases.