Immunization program in the USA
The vaccine against whooping cough is known as pertussis vaccine but is usually given combined with tetanus and diphtheria as DTaP vaccine (Tetanus, diphtheria, acellular pertussis) for the primary course.
It is recommended to be given as a course of six, at the following ages; 2 months, 4 months, 6 months, 15-18 months, 4-6 years and 11-12 years.
See CDC schedule
From 3 years onwards reduced diphtheria vaccines have to used, (TdaP).
The CDC has recently recommended the use of a further shot at 11-12 years of age, of Tdap vaccine in place of the previously recommended Td (tetanus and low dose diphtheria). Tdap contains pertussis antigens sufficient to boost immunity in those who have had the recommended childhood DTaP series. If Td has already been given, then Tdap can be given in addition, ideally with a five year gap, but straight away if there is going to be benefit.
One of the two Tdap vaccines (Adacel) is licensed for 11 to 64 year olds. It should be used instead of Td and is advised for adults who are likely to transmit pertussis to infants of 12 months and under, that is, parents, health care workers and those anticipating pregnancy.
Boostrix is the Tdap now licensed for 10 year olds and older in the USA and can be used every 10 years. It is currently the only Tdap vaccine licenced for 65 years plus. There are slight differences but not of practical importance.
It is not policy to boost with it repeatedly but neither is it disapproved of. There is no pertussis vaccine approved for 7-10 year olds, but this should not prevent unimmunized children of this age being given vaccine if they need it. Full up to date details of which vaccine to use and why can be seen in this CDC paper.