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Issue 1004: July 11, 2012

Ask the Experts: CDC Experts Answer Your Questions

All the questions and answers in this edition of IAC Express are based on common vaccination questions asked of CDC and IAC. Most of these Q&As first appeared in the May 2012 issue of Needle Tips.

IAC extends thanks to our experts, medical epidemiologist Andrew T. Kroger, MD, MPH; nurse educator Donna L. Weaver, RN, MN; and medical officer Iyabode Akinsanya-Beysolow, MD, MPH. All are with the National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC).

Questions and Answers
Q: What are the minimum intervals for giving the 3-dose series of Twinrix (hepatitis A-hepatitis B vaccine; GSK)?

A: Minimum intervals for Twinrix are 4 weeks between dose #1 and dose #2, and 5 months between dose #2 and dose #3.

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Q: When reconstituting a vaccine with the manufacturer-supplied diluent, should the clinic nurse administer exactly 0.5 mL and then discard the rest?

A: No. The nurse should administer the entire volume supplied. The package inserts include this information.

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Q: Should we fill out a report with the Vaccine Adverse Event Reporting System (VAERS) if a patient faints after getting a vaccination, even if no injury or complication resulted?

A: Yes. VAERS looks for trends, so such information is helpful. To find out about VAERS and the kinds of events you should report to the system, visit the VAERS website.

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Q: If a new version of a VIS becomes available, is it legal for us to use up the outdated VISs or do we have to discard them and provide the most up-to-date version?

A: When a new or updated VIS is released, CDC posts information on its website that indicates if healthcare providers can use up their stock of the old version of the VIS or should discard the old version and begin using the new VIS right away. The answer generally depends on how significantly the VIS was changed. You can tell what has been changed recently by going to the CDC VIS News website.

To determine whether you need to use the new one versus the old, you can have CDC email you an update by subscribing to CDC’s free email subscription service. After you’ve signed up, you’ll be taken to a page with lots of options. Once there, check the Vaccine Information Statements box under the section titled “Vaccines & Immunizations.”

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Q: A 10-year-old girl came to our immunization clinic, and the nurse noted crusted lesions on her arms and legs. The parent said the child had had chickenpox a week earlier. The girl was not ill, so we vaccinated her. But now I am wondering if her recent case of chickenpox might interfere with her immune response to vaccines.

A: Do not be concerned that the girl’s recent case of chickenpox will interfere with her immune response. Previous history of chickenpox disease, even recent disease, will not interfere with the immune response to different vaccines. To review the true contraindications and precautions to vaccination, consult IAC’s Guide to Contraindications and Precautions to Commonly Used Vaccines. Another helpful resource is ACIP’s General Recommendations on Immunization. It contains a useful table titled Conditions Commonly Misperceived as Contraindications to Vaccination.

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Q: A child wiggled when we were injecting a dose of vaccine, and approximately half the dose was lost. Should we revaccinate the child? If so, when?

A: When injectable vaccine volume is lost (patient moves, syringe leaks), it may be difficult to judge how much vaccine the patient actually received. In general, you should treat this as a nonstandard injectable dose and should not count it. If it was an inactivated vaccine, you should re-immunize the person as soon as possible. If it was a live vaccine, you can give another dose if you detect the error on the same clinic day; otherwise you should wait 28 days to give the next dose. However, if part of a dose of an oral vaccine (rotavirus) was spit out, count the dose and do not administer a second dose.

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Q: Should a healthcare worker who has just received a dose of a live virus vaccine (varicella, MMR, LAIV, yellow fever) stay away from work for a certain number of days?

A: No. Healthcare workers should not refrain from working after receiving live virus vaccines or any other vaccine.

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Q: How long must a patient wait after receiving zoster vaccine to start treatment with an immunosuppressive drug?

A: People who are immunosuppressed have a greater risk for developing herpes zoster and its severe morbidity and mortality. Therefore, reviewing a patient's vaccination history for zoster vaccine and other vaccines should be a key component in making a medical assessment of an immunocompetent patient age 60 years and older if the patient is anticipating starting immunosuppressive treatments or has diseases that might lead to immunodeficiency.

At the first possible clinical encounter, and while the patient's immunity is intact, administer 1 dose of zoster vaccine to unvaccinated patients who will be starting an immunosuppressive drug. Administer zoster vaccine at least 14 days before the start of immunosuppressive therapy. Some experts advise waiting 1 month after zoster vaccination (if possible) before beginning immunosuppressive therapy. For additional information, see the section titled "Persons Anticipating Immunosuppression" on pages 19–20 in ACIP's Prevention of Herpes Zoster.

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Q: Should we withhold rotavirus vaccine from an infant if someone in the household is receiving chemotherapy for cancer?

A: No. Having an immunocompromised family member is not a contraindication for receiving rotavirus vaccination. Please refer to page 19 of the ACIP statement Prevention of Rotavirus Gastroenteritis Among Infants and Children.

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Q: If a patient recently received a blood product, when can he or she receive MMR vaccine?

A: The answer depends on the specific blood product received. Please see Table 5 on page 39 of ACIP’s General Recommendations on Immunization.

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How to submit a question to Ask the Experts
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

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.

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

If you have a question about IAC materials or services, email

Please forward these Ask the Experts Q&As to your co-workers and suggest they subscribe to IAC Express.

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About IZ Express

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 and do not necessarily represent the official views of CDC.

IZ Express Disclaimer
ISSN 2771-8085

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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