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Issue 1115: April 16, 2014

Ask the Experts: CDC Experts Answer Your Questions

The questions and answers in this edition of IAC Express first appeared in the March 2014 issue of Needle Tips.

IAC extends thanks to our experts, medical officer Andrew T. Kroger, MD, MPH, and nurse educator Donna L. Weaver, RN, MN, from the National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC).

HPV Vaccines

DTaP and Tdap Influenza Vaccine MMR and Varicella Vaccines Vaccine Storage and Handling

HPV Vaccine
Q:  I read that HPV vaccination rates are still low. What can we do as providers to improve these rates?

A: Results from the Centers for Disease Control and Prevention's 2012 National Immunization Survey-Teen (NIS-Teen) indicate that HPV vaccination rates in girls age 13 through 17 years failed to increase between 2011 and 2012, and the 3-dose coverage rate actually declined slightly during this period. Just over half of the girls age 13 through 17 years had started the series that they should have completed by age 13 years. Only about one-third of girls this age had completed the series. In 2012, the first year HPV vaccine was routinely recommended for boys, 20.8% of boys age 13 through 17 years had received one dose and only 6.8% had received all three recommended doses. A summary of the 2012 NIS-Teen survey is available at, page 685.

Providers can improve uptake of this life-saving vaccine in two main ways. First, studies have shown that missed opportunities are a big problem. Eighty-four percent of girls unvaccinated for HPV had a healthcare visit where they received another vaccine such as Tdap, but not HPV. If HPV vaccine had been administered at the same visit, vaccination coverage for one or more doses could be nearly 93% instead of 54%.

Second, the 2012 NIS-Teen data show that not receiving a healthcare provider's recommendation for HPV vaccine was one of the five main reasons parents reported for not vaccinating daughters.

CDC urges healthcare providers to increase the consistency and strength of how they recommend HPV vaccine, especially when patients are age 11 or 12 years. The following resources can help providers with these conversations.

For more detailed information about HPV vaccination strategies for providers, visit

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DTaP and Tdap 
Q: A 17-year-old received a dose of Tdap vaccine when she was 12 years old. She is now pregnant. Should she get another dose of Tdap vaccine?

A: Yes. ACIP recommends a dose of Tdap during each pregnancy irrespective of the patient's prior history of receiving Tdap. To maximize the maternal antibody response and passive antibody transfer to the infant, optimal timing for Tdap administration is between 27 and 36 weeks gestation. For more information, see, page 131.

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Q: If Kinrix (DTaP-IPV; GSK) is inadvertently given to a child age 15 through 18 months, as the fourth DTaP dose and the third IPV dose, do the DTaP and IPV doses need to be repeated?

A: No, as long as minimum intervals between previous doses have been met. Kinrix is licensed and recommended only for children age 4 through 6 years. You should take measures to prevent this vaccine administration error in the future. However, you can count this as a valid dose for both DTaP and IPV as long as you met the minimum interval between administering dose #3 and dose #4 of DTaP (6 months) and dose #2 and dose #3 of IPV (4 weeks).

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Influenza Vaccine
Q: May Fluzone High-Dose (sanofi) be administered to patients younger than age 65 years?

A: No. Fluzone High-Dose is licensed only for persons age 65 years and older and is not recommended for younger people. See MMWR, April 30, 2010, available at for details about the licensure of this vaccine.

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MMR and Varicella Vaccines
Q: Would you consider a healthcare provider with 2 documented doses of MMR vaccine (Merck) to be immune even if their serology for 1 or more of the antigens comes back negative?

A: Yes. Healthcare personnel (HCP) with 2 documented doses of MMR vaccine are considered to be immune regardless of the results of a subsequent serologic test for measles, mumps, or rubella. Documented age-appropriate vaccination supersedes the results of subsequent serologic testing. HCP who do not have documentation of MMR vaccination and whose serologic test is interpreted as "indeterminate" or "equivocal" should be considered not immune and should receive 2 doses of MMR. ACIP does not recommend serologic testing after vaccination. For more information, see ACIP's recommendations on the use of MMR at, page 22.

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Q: I have patients who claim to remember receiving MMR vaccine but have no written record, or whose parents report the patient has been vaccinated. Should I accept this as evidence of vaccination? A: 

No. Self-reported doses and history of vaccination provided by a parent or other caregiver are not considered valid. You should only accept a written, dated record as evidence of vaccination.

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Q: We have adult patients in our practice at high risk for measles, including patients going back to college or preparing for international travel, who don't remember ever receiving MMR vaccine or having had measles disease. How should we manage these patients?

A: You have two options. You can test for immunity or you can just give 2 doses of MMR at least 4 weeks apart. There is no harm in giving MMR vaccine to a person who may already be immune to one or more of the vaccine viruses. If you or the patient opt for testing, and the tests indicate the patient is not immune to one or more of the vaccine components, give your patient 2 doses of MMR at least 4 weeks apart. If any test results are indeterminate or equivocal, consider your patient nonimmune. ACIP does not recommend serologic testing after vaccination because commercial tests may not be sensitive enough to reliably detect vaccine-induced immunity.

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Q: I have a 45-year-old patient who is traveling to Jordan to work with Syrian refugees. She doesn't recall ever getting a second dose of MMR (she didn't go to college and never worked in healthcare). She was rubella immune when pregnant 20 years ago. Her measles titer is negative. Would you recommend a second dose of MMR vaccine?

A: Yes. ACIP recommends 2 doses of MMR given at least 4 weeks apart for any adult born in 1957 or later who plans to travel internationally. There is no harm in giving MMR vaccine to a person who may already be immune to one or more of the vaccine viruses.

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Q: If a 5-year-old child has never received any doses of MMR or varicella vaccine and now the parents want him to catch up with the combination vaccine MMRV (ProQuad; Merck), what is the spacing requirement between the two doses?

A: Twelve weeks. The spacing between doses of a combination vaccine depends on the longest minimum interval of a component. The minimum interval between doses of MMR is 4 weeks; the minimum interval between doses of varicella vaccine is 12 weeks for a child this age. So you should wait 12 weeks between the doses of MMRV for the two doses to be valid.

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Q: MMRV was mistakenly given to a 31-year-old instead of MMR. Can this be considered a valid dose?

A: Yes, however, this issue is not addressed in the 2010 MMRV ACIP recommendations. Although this is off-label use, CDC recommends that when a dose of MMRV is inadvertently given to a patient age 13 years and older, it may be counted towards completion of the MMR and varicella vaccine series and does not need to be repeated.

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Vaccine Storage and Handling
Q: How long should we monitor the temperature in a new refrigerator before storing vaccines in it?

A: CDC recommends you allow one week of twice daily refrigerator and freezer temperature recordings, including minimum/maximum temperatures daily (preferably in the morning) to make sure temperatures are within the appropriate ranges before using the units to store vaccines. See CDC's “Vaccine Storage & Handling Toolkit” for useful information on vaccine storage and handling at

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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 our 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 colleagues and ask them to 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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