Welcome to the Vaccines and Immunizations website.
Skip directly to the search box, site navigation, or content.

Department of Health and Human Services
Centers for Disease Control and Prevention

Vaccines & Immunizations

Vaccines and Preventable Diseases:

Pediarix - Questions and Answers
Questions submitted during immunization satellite broadcasts or through NIPINFO

Question and Answer image

For Health Professionals:

General Questions

  • Do you recommend Pediarix in spite of the higher risk of fever?
    This question refers to information released by the FDA when the vaccine was approved for use on December 16, 2002. The clinical trials did show a slightly higher rate of fever after vaccination with Pediarix than with other DTaP vaccines. The temperatures were slightly higher and not significant. If FDA had considered this to be a significant problem then they would not have approved the vaccine for use. FDA Talk Paper on Pediarix (exit) (2/20/03)

  • If you start the DTaP series with Pediarix, do you have to complete the series with Infanrix?

    Whenever feasible, use same brand of DTaP for all doses of the primary series. We do not have efficacy or safety data for a primary series using multiple brands of DTaP. However, there is no reason to believe, based on the data we have, that using another brand of DTaP would compromise either safety or efficacy. So do not let a child go out of your office without a dose just because you don’t have Infanrix. Use what you have in stock. (8/21/03)

  • Can we use Pediarix to complete the primary series if the child received DTaP from another manufacturer?

    Whenever feasible, the same brand of DTaP should be used for all doses of the primary series. However, if this isn't possible, use a different manufacturer's product rather than defer vaccination. (8/21/03)

  • If you start the IPV, DTaP, and Hepatitis B series with the individual vaccines, can you still use Pediarix for subsequent doses?

    Yes, if the child received Infanrix as the DTaP vaccine. It is preferable to use the same manufacturer's DTaP vaccine for all doses in the primary series. But if you do not know whether a child received Infanrix for prior doses, or if Pediarix is the only DTaP-containing vaccine available, Pediarix may still be used to complete the series. (8/21/03)

  • Please comment on the thimerosal used in the manufacture of Pediarix and the implications for giving the vaccine.

    Pediarix does not contain thimerosal as a preservative. Thimerosal is used during the early stages of production, and subsequently removed, leaving only a clinically insignificant trace. (8/21/03)

  • Is Pediarix vaccine made from fetal embryos?

    None of the components of Pediarix are produced using human cell cultures. For information about the components of Pediarix components and its manufacturing process, see the manufacturer’s product informationAdobe Acrobat print-friendly PDF file. (8/21/03)

  • Please clarify whether or not Pediarix may be used for infants whose mothers are HBsAg-positive.

    Although not labeled for this indication by FDA, Pediarix may be used in infants whose mothers are HBsAg-positive or whose HBsAg status is not known. ACIP approved this off-label use of the vaccine in February 2003. (02/26/04)

  • Why is Pediarix not recommended for booster doses?

    Pediarix is not FDA approved for doses four or five of the DTaP series. This makes sense because using Pediarix for the 4th and 5th doses would result in a lot of extra doses of Hepatitis B. If the child received a birth dose of Hepatitis B vaccine and then 4 or 5 doses of Pediarix, that would mean the child received 5 or 6 doses of Hepatitis B vaccine, which is far more than is recommended and far more than anyone needs. (02/26/04)

top of page


  • For older children, less than 7 years of age, with no immunization record or an incomplete record, can Pediarix be used for the first three doses?

    Yes, Pediarix is licensed for the 3-dose primary series of DTaP, IPV, and Hepatitis B for a child 6 weeks up to 7 years of age. (8/21/03)

  • We have been told that the minimum interval between doses one and two of Pediarix is 6 weeks. You mentioned on a satellite broadcast that the minimum interval is 4 weeks. Please clarify?

    The minimum interval between any two doses is equivalent to the longest interval recommended for any of the individual components for those doses. The minimum interval between the first and second doses of DTaP, IPV, or Hepatitis B is 4 weeks, so 4 weeks is the minimum interval for Pediarix. The minimum interval between the second and third doses is dictated by the Hepatitis B component. There must be 8 weeks between the second and third doses AND at least 16 weeks between the first and third doses. The same guideline applies to the minimum ages. (8/21/03)

  • Since Pediarix is now available, should we continue to give a birth dose of Hepatitis B vaccine?

    Yes, CDC and AAP still encourage parents to get their children the first dose of hepatitis B vaccine at birth. (8/21/03)

  • If a child gets his 3rd dose of Pediarix before 6 months, will he need an additional dose at 6 months of age?

    The March 14, 2003 MMWR announcement of Pediarix states that the third dose should not be given before age 24 weeks. In General Recommendation on Immunization, ACIP states that vaccine doses administered 5 or more days before the minimum age should be repeated on or after the child reaches the minimum age and 4 or more weeks after the invalid dose. www.cdc.gov/mmwr/PDF/rr/rr5102.pdf Adobe Acrobat print-friendly PDF file and www.cdc.gov/mmwr/preview/mmwrhtml/mm5210a8.htm (8/21/03)

  • What is ACIP’s stand on informing parents that using Pediarix for 3 doses is O.K. for children who have already had a birth dose of Hepatitis B vaccine?

    It is reasonable to disclose the fact that the child is going to receive a fourth dose. You should also add that ACIP and the American Academy of Pediatrics (AAP) consider this an acceptable practice. It is not a problem. In fact, you could argue that it will make their antibody titers even higher. Inform the parent that this practice has been considered very carefully by the ACIP and the AAP and in their opinion there is really no harm and no problem with giving the extra dose. We do want to continue to give the birth dose of hepatitis B vaccine. That is a very important intervention.

  • If a child did not receive the birth dose of Hepatitis B vaccine should you start Pediarix on the first office visit?

    Yes, you can. We would prefer that the first dose be given as Hepatitis B vaccine in the hospital as a birth dose. However, if for some reason the did not get it – for instance, you documented that the mother was Hepatitis B surface antigen negative – it is appropriate to use Pediarix or Comvax for that matter. Remember, both of these vaccines (Pediarix and Comvax) should not be given before 6 weeks of age. These are not vaccines that you can give at one month of age. You wait until they are at least 6 weeks of age. (8/21/03)

  • If a child receives a birth dose of Hepatitis B vaccine and Comvax at 2 months of age, can the child receive Pediarix at 4 months of age?

    Yes, as long as you observe the minimum ages and minimum intervals, both vaccines can be used. (8/21/03)

  • Is it necessary to give an additional dose of Hepatitis B vaccine if Pediarix is given prior to 6 months of age?

    When administering combination vaccines you should still apply the minimum ages and minimum intervals for the individual components. ACIP recommends that doses administered 5 or more days earlier than the minimum interval or age should not be counted as valid doses and should be repeated as age-appropriate. The repeat dose should be spaced after the invalid dose by the recommended minimum interval for that dose. The 3rd dose of PEDIARIX™ should be given at least 16 weeks after the first dose, preferably at 6 months of age but not before 24 weeks of age. www.cdc.gov/mmwr/preview/mmwrhtml/mm5210a8.htm and www.cdc.gov/vaccines/programs/vfc/downloads/resoultions/1003hepb.pdf Adobe Acrobat print-friendly PDF file (8/21/03)

  • If dose one in the vaccination series is Pediarix (DTaP, IPV, Hepatitis B) and the second dose in the series is separate DTaP, IPV, and Hepatitis B vaccines, does the IPV count since it is a different IPV than the one in the combined Pediarix vaccine?

    Yes, all doses in the combined vaccine and the separate vaccines can be counted as valid doses as long as none of the doses violates minimum age and minimum interval guidelines. These vaccines are all licensed by FDA. (2/20/03)

top of page

Non-CDC Link Disclaimer: Links to non-Federal organizations found at this site are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. The CDC is not responsible for the content of the individual organization web pages found at these links.

.pdf files: To view and print the .pdf files on this site, you will need Adobe Acrobat Reader. Use this link to obtain a free copy of Adobe Acrobat Reader (exit). We highly recommend that you upgrade to the latest version if haven't already.

 Return to Q&A Main Page

This page last modified on February 9, 2005
Content last reviewed on February 9, 2005
Content Source: National Center for Immunization and Respiratory Diseases

Quick Links

Related Acronyms

Safer Healthier People

Centers for Disease Control and Prevention 1600 Clifton Rd, Atlanta, GA 30333, U.S.A
Public Inquiries: 1-800-CDC-INFO (232-4636); 1-888-232-6348 (TTY)

Vaccines and Immunizations