Final answer:
The side effects of a DtAP vaccine can occur immediately or within a few hours after receiving the vaccine, while more serious side effects may take a few days to a few weeks to appear.
Step-by-step explanation:
The side effects of a DtAP vaccine can occur in different timeframes depending on the individual and the specific reaction. However, most side effects occur immediately or within a few hours after receiving the vaccine. These immediate side effects may include soreness or redness at the injection site, mild fever, fussiness or irritability in infants and young children.
On the other hand, more serious side effects that are rare but possible with the DtAP vaccine may take longer to appear. These side effects, such as severe allergic reactions or other severe adverse effects, may occur within a few days to a few weeks after receiving the vaccine.