has been refreshed! Take a tour.

Issue 1131: July 10, 2014

Ask the Experts: CDC Experts Answer Your Questions

The questions and answers in this edition of IAC Express first appeared in the July 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, both from the National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC).

MMR Vaccine

Varicella Vaccine Tdap Vaccine HPV Vaccine Pneumococcal Vaccine Zoster Vaccine Vaccine Storage and Handling General Vaccine Questions

MMR Vaccine
Q: Many people age 60 years and older do not have records indicating what type of measles vaccine they received as children in the early 1960s. What measles vaccine was most frequently given in that time period? That guidance would assist many older people who would prefer not to be revaccinated.

A: Both killed and live attenuated measles vaccines became available in 1963. Live attenuated vaccine was used more often than killed vaccine. The killed vaccine was found to be not effective and people who received it should be revaccinated with live vaccine. Without a written record, it is not possible to know what type of vaccine an individual may have received. So persons born during or after 1957 who received killed measles vaccine or measles vaccine of unknown type, or who cannot document having been vaccinated or having laboratory-confirmed measles disease should receive at least 1 dose of MMR. Some people at increased risk of exposure to measles (such as healthcare professionals and international travelers) should receive 2 doses of MMR separated by at least 4 weeks.

Back to top

Varicella Vaccine
Q: Does ACIP recommend giving varicella vaccine to infants before age 1 year if they are traveling internationally?

A: No. ACIP recommends giving a dose of MMR to infants age 6 through 11 months before international travel, but not varicella vaccine. Varicella vaccine is neither approved nor recommended for children younger than age 12 months in any situation.

Back to top

Tdap  Vaccine
Q: We see many 10-year-olds for middle school entry immunization. Is one brand of Tdap preferred for this age group?

A: No. In March 2014, FDA lowered the age indication for Adacel brand Tdap vaccine (sanofi) from age 11 years to age 10 years. Both Tdap products, Adacel and Boostrix (GSK), now have the same lower age indication.

Back to top

Q: Is it acceptable to give breastfeeding mothers Tdap vaccine?

A: Yes. Women who have never received Tdap and who did not receive it during pregnancy should receive it immediately postpartum or as soon as possible thereafter. Breastfeeding does not decrease the immune response to routine childhood vaccines and is not a contraindication for any vaccine except smallpox. Breastfeeding is a precaution for yellow fever vaccine and the vaccine can be given for travel when indicated.

Back to top

HPV Vaccine
Q:  Can human papillomavirus (HPV) be transmitted by non-sexual transmission routes, such as clothing, undergarments, sex toys, or surfaces?

A: Nonsexual HPV transmission is theoretically possible but has not been definitely demonstrated. This is mainly because HPV can't be cultured and DNA detection from the environment is difficult and likely prone to false negative results.

Back to top

Pneumococcal Vaccine
Q: Is pneumococcal polysaccharide vaccine indicated for former smokers?

A: Pneumococcal polysaccharide vaccine (PPSV23, Pneumovax, Merck) is currently recommended for people age 19 through 64 years who actively smoke cigarettes (see However, chronic lung disease is an indication for PPSV23, which could be applicable for former smokers.

Back to top

Zoster Vaccine
Q: I know that ACIP only recommends zoster vaccine for adults age 60 years and older, although it is licensed for use in those 50 years and older. If I choose to vaccinate patients age 50–59 years, are there any criteria as to which patients in this age group might benefit most from zoster vaccination?

A: CDC had the following to say about your question in a November 11, 2011, issue of MMWR titled "Update on Herpes Zoster Vaccine: Licensure for Persons Aged 50 Through 59 Years" ( "For vaccination providers who choose to use Zostavax among certain patients aged 50 through 59 years despite the absence of an ACIP recommendation, factors that might be considered include particularly poor anticipated tolerance of herpes zoster or postherpetic neuralgia symptoms (e.g., attributable to preexisting chronic pain, severe depression, or other comorbid conditions; inability to tolerate treatment medications because of hypersensitivity or interactions with other chronic medications; and occupational considerations)."

Back to top

Vaccine Storage and Handling
Q: How long do we need to keep our refrigerator/freezer temperature tracking logs?

A: CDC recommends that refrigerator and freezer temperature logs be kept for at least 3 years. (See, page 52.) The reasoning is that it is useful to be able to look back at the record to help determine if a unit is developing a problem.

Individual state Vaccines For Children (VFC) programs may have different requirements for retaining temperature logs. You should contact your state program for this information. Contact information for state immunization programs is available at

Back to top

General Vaccine Questions
Q: What do we legally need to record when giving an immunization to a patient?

A: It is important to know the federal requirements for documenting the vaccines administered to your patients. The requirements are defined in the National Childhood Vaccine Injury Act enacted in 1986. The law applies to all routinely recommended childhood vaccines, regardless of the age of the patient receiving the vaccines. The only vaccines not included in this law are pneumococcal polysaccharide, zoster, and certain infrequently used vaccines, such as rabies and Japanese encephalitis.

The following information must be documented on the patient's paper or electronic medical record or on a permanent office log:
  1. The vaccine manufacturer.
  2. The lot number of the vaccine..
  3. The date the vaccine is administered.
  4. The name, office address, and title of the healthcare provider administering the vaccine. [Editor's Note: On July 31, 2104, IAC corrected an error in this statement of the "Ask the Experts" answer, which had previously stated that a "signature (electronic is acceptable) of the person administering the vaccine. Initials of the vaccine administrator ..." was required by federal law.]
  5. The Vaccine Information Statement (VIS) edition date located in the lower right corner on the back of the VIS. When administering combination vaccines, all applicable VISs should be given and the individual VIS edition dates recorded..
  6. The date the VIS is given to the patient, parent, or guardian.
The federally required information should be both permanent and accessible.

Federal law does not require a parent, patient, or guardian to sign a consent form in order to receive a vaccination; providing them with the appropriate VIS(s) and answering their questions is sufficient under federal law.

Back to top

Q: In updating immunizations for immigration ("green card") exams, I regularly come across intervals between catch-up vaccine doses that are shorter than ACIP recommendations—most often the last 2 doses of IPV are given less than 6 months apart, but also sometimes the 2 doses of varicella are given less than 3 months apart, and the next-to-last and last Td are given less than 6 months apart. How significant is this in terms of immunity?

A: The significance of non-standard intervals probably depends on the vaccine and the dose. This is a complex issue—studies have not been done to examine the effect of various intervals between doses on the immunogenicity of those doses. But ACIP has examined the available data and made recommendations about the minimum acceptable interval between doses for that dose to be considered valid (there is no maximum interval between doses). These minimum intervals are published as Table 1 in ACIP's General Recommendations on Immunization, available at, pages 36–37. Doses with a minimum interval less than the recommended minimum, as described in Table 1, should not be counted as valid. More details on this topic can be found in the General Recommendations.

Back to top

Q: Is it standard practice to revaccinate a child who is adopted from another country?

A: No. According to ACIP, vaccines administered outside the U.S. generally can be accepted as valid if the schedule (i.e., minimum ages and intervals) is similar to that recommended in the U.S. However, with the exception of the influenza vaccine and PPSV23, only written documentation should be accepted as evidence of previous vaccination. In general, if records cannot be located or will definitely not be available anywhere because of the patient's circumstances, children without adequate documentation should be considered susceptible and should be started on the age-appropriate vaccination schedule. Serologic testing for immunity is an alternative to vaccination for certain antigens. More information is available in the ACIP General Recommendations on Immunization, available at, pages 27–29.

Back to top
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 promise 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.

Back to top

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

This page was updated on .