Issue 1060: June 12, 2013

Ask the Experts: CDC Experts Answer Your Questions

The questions and answers in this edition of IAC Express first appeared in the May 2013 issue of Needle Tips. All relate to new recommendations or frequently asked questions.

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).

• Q: Please review the most recent ACIP changes in recommendations for use of PCV13 in children. 
• Q: If a patient has already had PPSV23 for his high-risk condition and also needs PCV13 for the same condition, how long should we wait before administering PCV13?
• Q: I work in a family medicine clinic that sees patients (children and adults) who are asplenic. Can we give them Hib vaccine since they are at high risk for Haemophilus influenzae type b disease?
• Q: I have a patient who is eligible for zoster vaccination who is going to be receiving chemotherapy soon. What are the guidelines in such a situation?
• Q: A 33-year-old patient in my practice has already suffered from three episodes of shingles. He would like to receive the zoster vaccine. Is this a good idea?
• Q: Some women have closely spaced pregnancies. Should we give Tdap during each pregnancy, even if it means such women would get 2 doses within 12 months?
• Q: At what gestational age of pregnancy should we vaccinate pregnant women with Tdap?
• Q: We would like to avoid stocking both Tdap and Td vaccines. Is CDC likely to recommend that Tdap completely replace Td in the immunization schedule in the near future?
• Q: The recently updated ACIP recommendations, Prevention and Control of Meningococcal Disease, advise using MCV4 in certain adults older than age 55. Please give me more details.

A: At its February 2013 meeting, ACIP voted to recommend that children age 6 through 18 years who have certain high-risk conditions be vaccinated with PCV13. Children who have no history of receiving PCV13 should receive a single dose if they have (1) functional or anatomic asplenia, including sickle cell disease, (2) HIV infection or other immunocompromising condition, (3) a cochlear implant, or (4) a CSF leak. Previous ACIP recommendations put these children in a “may be vaccinated” category. This new recommendation is now consistent with ACIP’s June 2012 recommendation that adults age 19 years and older with the same high-risk conditions be vaccinated with PCV13. The recommendations for high-risk adults were published in MMWR on October 12, 2012.

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A: The recommended interval between administering PPSV23 and subsequent PCV13 is 8 weeks for children and 1 year for adults. The recommended intervals are based on a hypothetical concern about interference between PCV13 and PPSV23. The shorter interval for children is driven by the need to not miss an opportunity to vaccinate with PCV13.

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A: Yes. In February 2013, ACIP voted to approve updated recommendations for the use of Hib vaccine in people with asplenia. The recommendations are to give 1 dose of Hib vaccine to asplenic patients age 5 years and older (including adults) if they have no history of receiving the vaccine. In addition, patients age 15 months and older (including adults) who are undergoing elective splenectomy should receive 1 dose if they have no history of receiving the vaccine. Ideally, administer the dose a minimum of 14 days before surgery. If the dose is not given before surgery, administer it after the procedure as soon as the patient’s condition is stable. If the splenectomy was performed in the past, and there is no history of Hib vaccination, the vaccine should be given at the next clinic visit.

A: The risk for zoster and its severe morbidity and mortality is much greater for immunosuppressed people. In this situation, the first step is to review the patient’s vaccine history for zoster and other vaccines. Immunocompetent patients 60 years and older who have never received zoster vaccine and who anticipate starting immunosuppressive treatments or who have diseases that might lead to immunodeficiency should receive 1 dose of the vaccine as soon as possible, while their immunity is intact. Administer zoster vaccine at least 14 days before immunosuppressive therapy begins. Some experts advise delaying the start of immunosuppressive therapy until 1 month after zoster is administered, if delay is possible. See pages 19–20 of the ACIP recommendations Prevention of Herpes Zoster.

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A: Though shingles vaccine (Zostavax, Merck) is FDA-licensed for people age 50 and older, ACIP recommends it routinely only for people age 60 and older. ACIP does not have a recommendation to administer the vaccine to younger people with recurrent zoster episodes. However, physicians may choose to administer a vaccine off-label, if in their clinical judgment, they think the vaccine is indicated. The patient should be informed that the use is off-label, and that the safety and efficacy of the vaccine has not been tested in people younger than 50.

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A: Yes. ACIP looked into this issue and included related information in its recommendations published in MMWR on February 22, 2013 (pages 131–135). ACIP reviewed available data on birth statistics and discovered that among U.S. women who have more than one pregnancy, a very small percentage (2.5%) have an interval of 12 months or less between births. The majority of women who have two pregnancies have an interval of 13 months or more between births. Approximately 5% of women have four or more babies. ACIP concluded that (1) the interval between subsequent pregnancies is likely to be longer than is the persistence of maternal anti-pertussis antibodies, (2) most women would receive only 2 doses of Tdap, and (3) a small proportion of women would receive 4 or more doses.

A theoretical risk exists for severe local reactions (e.g., arthus reactions, whole limb swelling) for pregnant women who have multiple, closely spaced pregnancies. However, the frequency of side effects depends on the vaccine’s antigen content and product formulation, as well as on preexisting maternal antibody levels related to the interval since the last dose and the number of doses received. The risk for severe adverse events has likely been reduced with current vaccine formulations (including Tdap), which contain lower doses of tetanus toxoid than did older vaccine formulations. ACIP believes the potential benefit of preventing pertussis morbidity and mortality in infants outweighs the theoretical concerns of possible severe adverse events in mothers.

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A: To maximize maternal antibody response and passive antibody transfer to the infant, the optimal time to administer Tdap is between 27 and 36 weeks’ gestation. However, Tdap can be administered at any time during pregnancy. Previously, CDC had recommended that Tdap vaccination occur after 20 weeks’ gestation.

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A: Currently, CDC recommends giving only 1 dose of Tdap to adolescents and adults who have not previously received the vaccine, with the exception of pregnant women, who should be vaccinated during each pregnancy. If CDC eventually recommends that people who are now recommended to receive only 1 dose of Tdap receive an additional dose, CDC is likely to recommend that they receive only 1 additional dose. Therefore, medical settings will need to continue to stock Td vaccine in order to administer it to patients who need to complete the full primary 3-dose tetanus and diphtheria series and also to administer 10-year booster doses of Td throughout the lifetime of those who have completed the primary series.

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A: Previously, ACIP recommended only the quadrivalent meningococcal polysaccharide vaccine (MPSV4, Menomune, sanofi pasteur) for use in adults age 56 years and older. The newest recommendations, published on March 22, 2013, call for use of quadrivalent meningococcal conjugate vaccine (MCV4: Menactra, sanofi pasteur; Menveo, Novartis) in adults age 56 years and older who (1) were vaccinated previously with MCV4 and now need revaccination or (2) are recommended to receive multiple doses (e.g., adults with asplenia, microbiologists working with Neisseria meningitidis). Both MCV4 vaccine products are licensed for use in people through age 55 years, which means that the use of these vaccines in people age 56 and older is off-label but ACIP-recommended.

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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.

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 admininfo@immunize.org.

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

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