Issue 1014: September 5, 2012

Ask the Experts: CDC Experts Answer Your Questions

All the questions and answers in this edition of IAC Express pertain to either new ACIP recommendations or reader questions. With the exception of the first two questions, all these Q&As first appeared in the August 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: Which children younger than age 9 years will need 2 doses of influenza vaccine in the 2012–13 influenza season?

A: Children age 6 months through 8 years should receive a second dose 4 weeks or more after the first dose if they (1) are receiving influenza vaccine for the first time or (2) did not get at least 2 doses of seasonal influenza vaccine since July 1, 2010.

CDC has developed an alternative approach that may be used with children who have documented histories (e.g., maintained in electronic registries) of influenza vaccination. By this approach, children age 6 months through 8 years need only 1 dose of vaccine in 2012–13 if they have received any of the following: (1) 2 or more doses of seasonal influenza vaccine since July 1, 2010; (2) at least 2 doses of seasonal vaccine given before July 1, 2010, and at least 1 dose of monovalent 2009 H1N1 vaccine; or (3) at least 1 dose of seasonal vaccine given before July 1, 2010, and at least 1 dose of seasonal vaccine since July 1, 2010.

For more details about the recommendations for which children need two doses, see Prevention and Control of Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP) — United States, 2012–13 Influenza Season (pages 613-614).

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Q: What is the latest ACIP guidance on influenza vaccination and egg allergy?

A: People who have experienced a serious systemic or anaphylactic reaction (e.g., hives, swelling of the lips or tongue, acute respiratory distress, or collapse) after eating eggs should consult a specialist for appropriate evaluation to help determine if vaccine should be administered.

A previous severe allergic reaction to influenza vaccine, regardless of the component suspected to be responsible for the reaction, is a contraindication to future receipt of the vaccine.

People who have documented immunoglobulin E (IgE)-mediated hypersensitivity to eggs, including those who have had occupational asthma or other allergic responses to egg protein, might also be at increased risk for allergic reactions to influenza vaccine. Protocols have been published for safely administering influenza vaccine to people with egg allergies.

Some people who report allergy to egg might not be egg allergic. If a person can eat lightly cooked eggs (e.g., scrambled eggs), they are unlikely to have an egg allergy. However, people who can tolerate egg in baked products (e.g., cake) might still have an egg allergy. If the person develops hives only after ingesting eggs, CDC recommends (1) they receive TIV (not LAIV), (2) the vaccine be administered by a healthcare provider familiar with the potential manifestations of egg allergy, and (3) the vaccine recipient be observed for at least 30 minutes after receipt of the vaccine for signs of a reaction.

For more details about giving influenza vaccine to people with a history of egg allergy, see Prevention and Control of Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP)—United States, 2012–13 Influenza Season (pages 616-617).

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Q: Why do we vaccinate pregnant women against influenza when it is not recommended to vaccinate infants younger than age 6 months?

A: ACIP has recommended vaccinating pregnant women with inactivated influenza vaccine (TIV) for a number of years. Pregnant women are a high-risk group for complications, hospitalization, and even death from influenza because of the increased physiologic strain of pregnancy on their heart, lungs, and immune system. Vaccination can occur in any trimester, including the first.
Influenza vaccine is not recommended for children younger than age 6 months because it is not approved for this age group. In addition, there are data that indicate that vaccinated pregnant women pass maternal antibodies to the fetus in the last few weeks of pregnancy; this helps protect the young infant against influenza. Vaccinating pregnant women thus protects women, their unborn babies, and their babies after birth.

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Q: A child received a 0.25 mL dose of inactivated influenza vaccine (TIV) at age 34 months. She is scheduled to return for the second dose at age 36 months. Should she receive a 0.25 mL dose or a 0.5 mL dose?

A: She should receive a 0.5 mL dose of TIV. Always administer the volume of vaccine appropriate to the age of the patient when the patient presents at the clinic for the dose.

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Q: Now that FDA has licensed Prevnar 13 (PCV13; Pfizer) for adults, does ACIP have recommendations for its use?

A: To date, ACIP has not made recommendations for routine use of PCV13 for adults; however, at its June 2012 meeting, ACIP voted to recommend administering 1 dose of PCV13 to adults age 19 and older who are at highest risk for invasive pneumococcal disease. This includes adults who are immunosuppressed and those with functional or anatomic asplenia, renal disease, CSF leak, and cochlear implants. ACIP voted to recommend that when healthcare providers vaccinate highest-risk patients who have never received a pneumococcal vaccine, the provider administer PCV13 first, then follow with a dose of pneumococcal polysaccharide vaccine (PPSV23) 8 weeks later, and follow with a second dose of PPSV23 5 years later. For highest-risk patients who have already received PPSV23, ACIP voted to recommend that healthcare professionals wait 1 year since the previous dose of PPSV23 before giving PCV13 to avoid interference between the vaccines. More detail will be included when MMWR publishes the recommendations.

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Q: I am confused about which adults to vaccinate with Tdap vaccine and which product to use. Please help!

A: CDC published updated recommendations on Tdap vaccination for adults in the June 29 issue of MMWR (pages 468–470). ACIP recommends that ALL adults age 19 years and older who have not yet received a dose of Tdap receive a single dose. Tdap should be administered regardless of interval since the last tetanus- or diphtheria-toxoid–containing vaccine (e.g., Td). After receiving Tdap, people should receive Td every 10 years for routine booster immunization against tetanus and diphtheria, according to previously published guidelines.

Providers should not miss an opportunity to vaccinate adults age 65 and older with Tdap. Therefore, providers may administer any Tdap vaccine they have available. When feasible, providers should administer Boostrix (Tdap; GSK) to adults age 65 and older as it is licensed for this age group. Adacel (Tdap; sanofi) is licensed for use in people age 11 through 64. However, ACIP concluded that either vaccine administered to a person age 65 or older is immunogenic and will provide protection. A dose of either vaccine is considered valid.

When a tetanus-toxoid–containing vaccine is needed for wound management in a person who has not previously received Tdap, the use of Tdap is preferred over Td.

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Q: Who should get a second dose of Tdap vaccine?

A: Currently, no one is recommended to receive more than 1 dose of Tdap. In the future, ACIP will discuss the need for administering additional doses of Tdap and the timing of revaccinating people who have received Tdap previously.

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Q: If Cervarix (HPV2; GSK) is inadvertently administered to a male, does the dose need to be repeated with Gardasil (HPV4; Merck)?

A: Yes. Cervarix is recommended for use only in females. There is no minimum interval between the invalid dose of Cervarix and the dose of Gardasil.
ACIP recommends routine vaccination of males age 11–12 years with HPV4 administered as a 3-dose series. The vaccination series can be started at age 9 years. Vaccination with HPV4 is also recommended for males age 13 through 21 years who have not been vaccinated previously or who have not completed the 3-dose series. Males age 22 through 26 years may be vaccinated with HPV4; ACIP specifically recommends routine vaccination with HPV4 through age 26 years for immunocompromised males and men who have sex with men if they have not been vaccinated previously or have not completed the 3-dose series.

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Q: If a healthcare worker does not have a history of varicella vaccination or disease but has had a clinically diagnosed case of shingles, does she or he still need varicella vaccination?

A: No. A healthcare provider’s diagnosis or verification of a history of shingles is acceptable evidence of immunity to varicella. According to ACIP, acceptable evidence of varicella immunity in healthcare personnel includes (1) documentation of 2 doses of varicella vaccine given at least 28 days apart, (2) history of varicella or herpes zoster based on physician diagnosis, (3) laboratory evidence of immunity, or (4) laboratory confirmation of disease.

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Q: ACIP recommends that adolescents who receive the first dose of meningococcal conjugate vaccine (MCV4) at age 13–15 years receive a one-time booster dose at age 16–18 years. Given how hard it is to get teens into a medical office, is it okay to give the doses close together if the opportunity arises? For example, if a patient got the first dose at age 15, and then came back for a sports physical at age 16, could we give the second dose of MCV4 then or should we try to space it out as far as possible (age 18)?

A: If the first dose is given at age 13 through 15 years, you can give the booster dose as early as age 16 years, with a minimum interval of 8 weeks from the previous dose. So, even if the patient got vaccinated at age 15 years 11 months, you could wait at least 8 weeks and then give the booster at age 16 years 1 month (or later) if you chose to do so.

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Q: Can you switch brands of rabies vaccine to complete the 4-dose series?

A: Yes. The two rabies vaccines licensed for use in the United States are interchangeable.

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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.

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Editorial Information

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