IAC Express 2008
Issue number 751: September 5, 2008
Contents of this Issue
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  1. Read "Ask the Experts" Q&As from CDC experts
AAFP, American Academy of Family Physicians; AAP, American Academy of Pediatrics; ACIP, Advisory Committee on Immunization Practices; AMA, American Medical Association; CDC, Centers for Disease Control and Prevention; FDA, Food and Drug Administration; IAC, Immunization Action Coalition; MMWR, Morbidity and Mortality Weekly Report; NCIRD, National Center for Immunization and Respiratory Diseases; NIVS, National Influenza Vaccine Summit; VIS, Vaccine Information Statement; VPD, vaccine-preventable disease; WHO, World Health Organization.
Issue 751: September 5, 2008
1.  Read "Ask the Experts" Q&As from CDC experts

Many readers of Needle Tips, Vaccinate Adults, and Vaccinate Women consistently rank "Ask the Experts" as their favorite feature in these publications. As a thank-you to our loyal IAC Express readers, we have decided to periodically publish an Extra Edition with new "Ask the Experts" Q&As answered by CDC experts.

IAC thanks William L. Atkinson, MD, MPH, and Andrew T. Kroger, MD, MPH, medical epidemiologists at the National Center for Immunization and Respiratory Diseases, CDC, for agreeing to answer the following questions.

Editor's note: Information about submitting a question to "Ask the Experts" is provided at the end of this IAC Express article.

A 60-year-old patient was given varicella vaccine instead of zoster vaccine. Should the patient still be given the zoster vaccine? If so, how long an interval should occur between the 2 doses?

ACIP states the following: "If a provider mistakenly administers varicella vaccine to a person for whom zoster vaccine is indicated, no specific safety concerns exist, but the dose should not be considered valid and the patient should be administered a dose of zoster vaccine during that same visit. If the error is not immediately detected, a dose of zoster vaccine should be administered as soon as possible but not within 28 days of the varicella vaccine dose to prevent potential interference of 2 doses of live attenuated virus."

To download the ACIP recommendations titled "Prevention of Herpes Zoster," go to: http://www.cdc.gov/mmwr/PDF/rr/rr5705.pdf

We mistakenly administered the Boostrix brand of Tdap to a 52-year-old patient instead of the Adacel brand of Tdap. Should the dose of Boostrix be counted as valid?

Currently, only Adacel Tdap (sanofi pasteur) is licensed and recommended for use in adults (Adacel is licensed for persons age 11-64 years). Boostrix Tdap (GlaxoSmithKline) is licensed for persons age 10–18 years.

According to ACIP, if Boostrix is administered in error to an adult age 19 or older, this dose should count as the Tdap dose and the patient should NOT receive an additional dose of Tdap (Adacel). The patient should be informed of the medical error in vaccine administration.

To help prevent inadvertent administration of Boostrix when Adacel is indicated, vaccine providers should examine the product labels carefully before administering these vaccines.

Can the parents of a newborn receive a dose of Tdap right after their child's birth to protect themselves and, indirectly, their newborn from pertussis, even though they had a dose of Td vaccine less than 2 years ago?

Yes. Parents should receive a single dose of Tdap as soon as possible to protect the baby from pertussis. If a dose of Td was given within the previous 2 years, parents should still be vaccinated with Tdap as soon as possible regardless of the time interval since the last dose of Td. Other household contacts who are not up to date with their pertussis-containing vaccinations should also be appropriately vaccinated.

How soon after receiving a dose of Td can a healthcare worker receive a dose of Tdap in order to protect vulnerable infants and others?

If they have not previously received Tdap, healthcare personnel in hospitals and ambulatory care settings who have direct patient contact should receive a single dose of Tdap as soon as feasible and without regard to the dosing interval since the last Td. There is no "minimum interval" one needs to wait between receiving Td and Tdap when it is given to protect infants or other vulnerable patients.

If a college student previously had 2 pediatric doses of hepatitis A vaccine, does he or she need a third dose as an adult?

No. A person is considered immune as long as she or he received 2 age-appropriate doses of hepatitis A vaccine (given at least 6 months apart) prior to age 19 years. There is no "booster" dose recommended.

If a woman's rubella test result shows she is "not immune" during a prenatal visit but she has 2 documented doses of MMR vaccine, does she need a third dose of MMR vaccine postpartum?

ACIP does not routinely recommend more than 2 doses of MMR vaccine. A negative serology after 2 documented doses probably represents a false negative (i.e., antibody titer too low to detect with commercial tests). If a person is found to have a negative serology after 2 documented doses of MMR, it is best to stop testing for rubella.

ACIP's recommendations for the use of MMR vaccine can be accessed here: http://www.cdc.gov/mmwr/PDF/rr/rr4708.pdf

What is the significance of the difference in the abbreviations for the vaccines DTaP (for children less than age 7 years) and Tdap (used in adolescents or adults)?

Both vaccines provide protection against diphtheria, tetanus, and pertussis, but DTaP has MORE diphtheria toxoid (3-5 times as much) and MORE pertussis antigen than the amount in the Tdap vaccines. This larger amount of antigen is reflected by the use of the capital letters "D" and "P" when writing DTaP (the pediatric vaccine). Because both DTaP and Tdap contain equal amounts of tetanus antigen, both vaccine abbreviations contain a capital "T."

IAC works with CDC to compile new "Ask the Experts" Q&As for our publications based on commonly asked questions. We also consider the need to provide information about new vaccines and recommendations. Most of the questions are thus a composite of several inquiries.

You can email your question about vaccines or immunization to IAC at admin@immunize.org. As we receive hundreds of emails each month, we cannot guarantee that we will print your specific question in the "Ask the Experts" feature. However, you will get an answer. To see if your question has already been answered, you can first check the "Ask the Experts" online archive at http://www.immunize.org/askexperts

You can also email CDC's immunization experts directly at nipinfo@cdc.gov. There is no charge for this service.

If you have a question about IAC materials or services, email admin@immunize.org

Please forward these "Ask the Experts" Q&As to your co-workers and suggest they subscribe to IAC Express at http://www.immunize.org/subscribe

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IZ Express is supported in part by Grant No. 1NH23IP922654 from CDC’s National Center for Immunization and Respiratory Diseases. Its contents are solely the responsibility of Immunize.org and do not necessarily represent the official views of CDC.

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Editorial Information

  • Editor-in-Chief
    Kelly L. Moore, MD, MPH
  • Managing Editor
    John D. Grabenstein, RPh, PhD
  • Associate Editor
    Sharon G. Humiston, MD, MPH
  • Writer/Publication Coordinator
    Taryn Chapman, MS
    Courtnay Londo, MA
  • Style and Copy Editor
    Marian Deegan, JD
  • Web Edition Managers
    Arkady Shakhnovich
    Jermaine Royes
  • Contributing Writer
    Laurel H. Wood, MPA
  • Technical Reviewer
    Kayla Ohlde

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