If Kinrix or Quadracel (DTaP-IPV) is inadvertently given to a child age 15 through 18 months, as the fourth DTaP dose and the third IPV dose, do the DTaP and IPV doses need to be repeated?

Since both Kinrix and Quadracel are licensed and recommended only for children ages 4 through 6 years, you should take measures to prevent this error in the future. However, you can count this as a valid dose for DTaP and IPV as long as you met the minimum interval between administering dose #3 and dose #4 of DTaP (6 months) and dose #2 and dose #3 of IPV (4 weeks).