Diphtheria, tentanus, pertussis immunisations? Where can I get them in us?

Dr. or Public Health. Most pediatricians and family physicians offer them in their offices, and you local dept. Of public health will also have them, often at a reduced prices.
Primary care office. Any primary care doctor should be able to give you the immunization. Or contact the county health department.
EVERYWHERE IN US. You can get it anywhere in us.Go to any primary care physicians office(family physician or pediatrician), and it is covered by most health insurances.Free clinics run by many health dept and hospitals also provide not only DTP but all other vaccines.