If a child 7 through 9 years of age has an incomplete history or no history of DTaP, DT, or Td can you use Tdap?
There is no Tdap vaccine approved by FDA or the ACIP for use in children 7 through 9 years of age. Td should be used. Appendix E of the ACIP Tdap Adolescent recommendations provides guidance in completing the series for children 7 through 10 years of age: http://www.cdc.gov/mmwr/PDF/rr/rr5503.pdf.