A 5-month-old infant inadvertently received a third dose of Vaxelis vaccine. Is this a valid dose?

The third dose of Vaxelis vaccine administered at age 5 months (less than 24 weeks of age) is not considered a valid dose of the HepB component, because the last dose of HepB vaccine should be given at 24 weeks of age or older. The child will need an additional dose of HepB vaccine at age 24 weeks or older, and at least 4 weeks after the inadvertent dose of Vaxelis. The DTaP and IPV components of the Vaxelis dose erroneously administered at age 5 months are considered valid doses and do not need to be repeated, as long as there was a minimum 4-week interval between the second and third doses of either component.