Revaccination is not recommended. Yes, however it is preferred to use the same vaccine for the three-dose series. Additional information on the immunogenicity and safety of a fifth dose of acellular vaccine is being collected and should be available before infants started on this new schedule are 4-6 years old and require a fifth dose . The fifth dose of either DTaP or DTP is not necessary if the fourth dose was given on or after the fourth birthday. None of these doses count, so DTP-1 is due today.
Some providers administer split-doses of vaccine in an attempt to reduce adverse effects.
Unfortunately, there is no evidence that splitting a dose of vaccine into two shots will significantly reduce adverse effects, and it may result in impaired immune response and inadequate protection. After the exam, you also assess her immunization status, and notice that she has received a total of 4 DTP vaccinations, with the 3rd and 4th doses administered at six and nine months respectively. Ashley should receive another dose of DTP today. Because the recommended minimum interval between the 3rd and 4th doses of DTP is six months, the dose Ashley received at nine months should not be counted. 1 Ashley should also receive a booster dose of DTP at four to six years of age.