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Education and Training
Immunization Update 2006
Questions & Answers
Questions submitted during the Immunization Update broadcast on August 10, 2006

Questions and Answers image

Questions about:

Hepatitis A

  1. Are there any projections to require hepatitis A vaccine for healthcare workers?

    No. ACIP does not recommend routine hepatitis A vaccination of healthcare workers because as an occupation they have not been shown to be at increased risk. However, many adults have non-occupational indications such as travel, for which the vaccine is indicated.

  2. Should we be vaccinating all persons younger than 18 years of age for hepatitis A?

    All children should receive hepatitis A vaccine at age 1 year (i.e., 12–23 months). Vaccination should be completed according to the licensed schedules and integrated into the routine childhood vaccination schedule. Children who are not vaccinated by age 2 years can be vaccinated at subsequent visits. States, counties, and communities with existing hepatitis A vaccination programs for children aged 2–18 years are encouraged to maintain these programs. In these areas, new efforts focused on routine vaccination of children aged 1 year should enhance, not replace, ongoing programs directed at a broader population of children. In areas without existing hepatitis A vaccination programs, catch-up vaccination of unvaccinated children aged 2–18 years can be considered. Such programs might especially be warranted in the context of increasing incidence or ongoing outbreaks among children or adolescents.

  3. Why was the age requirement for hepatitis A lowered to one year of age?

    The age was lowered to one year based on safety and efficacy data presented by the vaccine manufacturers to the FDA

  4. Can Twinrix be interchanged with hepatitis A and hepatitis B vaccines if the person is started on the single-antigen vaccines and then switched to Twinrix and vice versa?

    Because the hepatitis B component of Twinrix is equivalent to a standard adult dose of hepatitis B vaccine, the schedule is the same whether Twinrix or single-antigen hepatitis B vaccine is used.

    Single-antigen hepatitis A vaccine may be used to complete a series begun with Twinrix and vice versa. A person who receives one dose of Twinrix may complete the hepatitis A series with two doses of adult formulation hepatitis A vaccine separated by at least 5 months. A person who receives two doses of Twinrix may complete the hepatitis A series with one dose of adult formulation hepatitis A vaccine or Twinrix 5 months after the second dose. A person who begins the hepatitis A series with a dose of single-antigen hepatitis A vaccine may complete the series with two doses of Twinrix.

  5. If a person has a documented history of hepatitis A infection, does the person need hepatitis A vaccine?

    No. They are immune. However, if there is any doubt about whether the infection actually was hepatitis A, then take the conservative approach and vaccinate. The vaccine will not harm someone who is already immune.

  6. If a child is older than 2 years of age and has received one dose of hepatitis A vaccine, does ACIP recommend the 2nd dose of vaccine?

    Yes. For long-term protection the person should complete the series with the second dose.

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Human Papillomavirus

  1. What is the status of administering the HPV vaccine to males?

    The current HPV vaccine, Gardasil, is not FDA approved for use in males and there are no ACIP off-label recommendations to vaccinate males. The vaccine manufacturer is conducting clinical trials with males so at some later time they may apply to FDA to make the vaccine available to males.

  2. If a pregnant woman receives HPV vaccine in the first trimester, what effect is there on the fetus?

    HPV vaccine has not been causally associated with adverse outcomes of pregnancy or adverse events to the developing fetus. However, data on vaccination during pregnancy are limited and ACIP has adopted a conservative approach to the vaccination of pregnant women.

    If a woman is found to be pregnant after initiating the vaccination series, completion of the series should be delayed until after the pregnancy. If a dose is administered during pregnancy, there is no indication for intervention. A vaccine in pregnancy registry has been established by the manufacturer, and women vaccinated during pregnancy should be reported to (800) 986-8999. More information on vaccination during pregnancy is available at

  3. Can HPV vaccine be administered to teens without parental consent?

    Federal law will mandate the recording of certain information about each vaccination (e.g., manufacturer, lot number), and the provision of the appropriate Vaccine Information Statement(s); but there is no federal law requiring a parent/patient signature. However, providers should check with their state immunization program to determine whether additional requirements exist under state law.

  4. Is there any data regarding possible cervical changes that may occur later in life for young women who have received Gardasil?

    This vaccine has just recently been licensed and there are no long-term post-vaccination data available.

  5. Should a person who has been diagnosed with one of the HPV vaccine virus strains still be vaccinated?

    Yes, if the female is between 9 and 26 years of age. The vaccine will not treat an existing infection with one of the vaccine virus strains. However, in the clinical trials, females with current or past infection with one or more vaccine-related HPV types prior to vaccination were protected from the diseases caused by the other remaining HPV types contained in the vaccine.

  6. If I give a dose of HPV vaccine now and the patient does not return until 4 months later for the second dose, how long should I wait to administer the third dose?

    The minimum interval between the second and third doses of HPV vaccine is 12 weeks regardless of the length of the interval between the first and second doses. The minimum interval between the first two doses is 4 weeks, but there is no maximum interval.

  7. Why is HPV vaccine not recommended for women older than 26 years?

    The vaccine is approved only for use in females 9 through 26 years of age because there are no safety or efficacy data for older women. Studies are currently being conducted in women 27 years of age and older.

  8. How is the HPV transmitted?

    Transmission of genital HPV is predominantly associated with sexual activity; viable HPV and microtrauma to skin or mucous membranes are likely required. Transmission can occur from asymptomatic and subclinical patients. Infectiousness after treatment of warts or cervical cell abnormalities is unknown. Transmission by fomites has never been documented.

    Although rare, genital HPV infection with low-risk types can be transmitted from mother to baby during delivery and causes respiratory tract warts in the baby, known as recurrent respiratory papillomatosis (RRP).

    The following website provides more information on HPV and HPV transmission,

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  1. If immunity to influenza wanes, why does a child need only one dose instead of two doses if they were vaccinated in a previous influenza season?

    The first dose of influenza vaccine given to a child younger than 9 years of age is a "priming" dose. It offers little protection. It is the second dose that offers the protection. There is no need for priming in subsequent years, so only one dose is recommended. Persons 9 years of age and older are assumed to have been exposed to influenza viruses, and will have been primed by that exposure. Therefore, they do not need a second dose of vaccine in one year, even if they are receiving it for the first time. Booster doses are not recommended for anyone because data do not indicate that booster doses increase protection.

  2. Is there an influenza vaccine available for persons with a severe allergy to eggs?

    No. Persons who have a severe life-threatening allergy to eggs should be evaluated by an allergist who may be able to desensitize them so that they can receive the vaccine. If not, then the other option for these persons is an antiviral.

  3. What should we do if we discover that adults were given influenza vaccine with a 5/8” needle?

    Although it is likely that these adults did not get the full dose of vaccine into their muscle, ACIP does not recommend revaccination. These persons likely received some benefit from the vaccine, but for optimal immune response the correct needle length should be used, (page 12).

  4. Is it OK to pre-draw influenza vaccine for a large clinic?

    The National Center for Immunization and Respiratory Diseases and the vaccine manufacturers strongly discourage prefilling syringes with vaccine prior to usage. With the exception of manufacturer-prefilled syringes, syringes used to administer vaccines are meant for administration, not storage. However, if you must prefill syringes for a large clinic, please review guidelines in the “Vaccine Storage & Handling Toolkit”, (Chapter 11, pages 6-8). Any non-manufacturer prefilled syringes should be discarded at the end of the clinic day.

  5. If you are vaccinating a child between the ages of 5 and 8 years with influenza vaccine for the first time, can you use one dose of LAIV and one dose of TIV?

    Yes. If the child is healthy you can give one dose of LAIV and one dose of TIV. If LAIV is administered first, wait at least 6 weeks to administer the TIV dose. If TIV is administered first, wait at least 4 weeks to administer the LAIV dose.

  6. How long after vaccination with LAIV should a person wait to become pregnant?

    ACIP has not directly addressed this situation. However, with other live virus vaccines the recommendation is to wait at least 4 weeks before becoming pregnant.

  7. Is LAIV going to be recommended for children 6 months to 5 years of age?

    In July, 2006 the vaccine manufacturer submitted an application to FDA to approve the use of CAIV-T (Flu-Mist) in persons 6 months through 49 years of age. FDA review of the data is pending,

  8. Why isn’t a second dose of influenza recommended later in the season to boost immunity?

    There is no evidence this is an effective strategy for preventing influenza.

  9. What is the basis for the recommendation that LAIV should only be given to healthy person up through 49 years of age?

    LAIV is only recommended for healthy, nonpregnant persons 5 years through 49 years of age because this is the population in which the clinical trials were conducted. FDA licensed the vaccine for use based on the manufacturer’s clinical trials data. There are no ACIP off-label recommendations to administer LAIV to any other age groups.

  10. We have patients with hypertension who are at risk for stroke. Should they be prioritized to receive influenza vaccine?

    Influenza vaccine is recommended for everyone 50 years of age and older. For persons younger than 50 years of age, isolated hypertension is not considered a risk factor for influenza. However, it is important to screen these persons carefully. They may have another chronic illness such as chronic cardiac disease or diabetes that does put them at high risk for influenza complications.

  11. If someone receives LAIV, is it possible to have a false-positive culture later on?

    Yes. LAIV contains live viruses so a false-positive antigen test is possible for anywhere from 1-2 weeks after vaccination.

  12. Is the definition of healthcare worker evolving? Previously that designation referred to hands-on providers. Now, however, other employees in a healthcare setting are also being considered.

    We are getting away from “workers” and moving to “providers.” This means not only people who have close contact with patients or give vaccines, but also other personnel, including anyyone who works in a healthcare facility or provides any type of care (dieticians, clerks, janitorial staff, etc.). Which definition applies depends on the disease. For example, with respiratory or airborne infections, it doesn’t matter if the employee is hands-on or in direct contact with the patient. In this case, the definition should be wide enough to include anyone who shares the air in the facility.

  13. Where can I find the influenza declination form?

    This form (which may be signed by healthcare providers to document that they understand the consequences of declining influenza vaccination) is available from the Immunization Action Coalition at

  14. When did the influenza recommendation for pregnant women change from the 2nd & 3rd trimester to any trimester?

    This recommendation changed in 2004 ( The risk to the fetus is theoretical and the main reason for avoiding the first trimester seemed to be associated with the fact that most spontaneous abortions occur in the first trimester and that the vaccine might be blamed if given in the first trimester. Ultimately the risk of influenza infection was felt to outweigh any theoretical risk from vaccination.

  15. What is the difference between whole virus influenza vaccine and split-virus influenza vaccine?

    You might say split-virus is analogous to whole-virus as skim milk is to whole milk. The virus is basically stripped down to the specific protein subunits that will induce an immune response, thus decreasing the risks of adverse reactions associated with whole viruses.

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  1. Please review the mumps vaccination recommendations in response to the recent Midwest outbreak.

    Updated mumps vaccination recommendations are available at

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  1. What should I tell providers who insist on starting the rotavirus vaccine series at the 4 month visit?

    FDA did not approve – and ACIP does not recommend starting – rotavirus vaccination after a child reaches 13 weeks of age. There are no safety data for administering the first dose of rotavirus vaccine beyond 12 weeks of age.

  2. What are the guidelines for providing rotavirus vaccine to premature infants?

    Practitioners should consider the potential risks and benefits when vaccinating premature infants (<37 weeks gestation) against rotavirus. Limited data suggest that premature infants are at increased risk for hospitalization from viral gastroenteritis during their first year of life. In clinical trials, the safety and efficacy of rotavirus vaccine appeared to be similar for premature and term infants, although relatively few preterm infants were evaluated.

    The lower level of maternal antibody to rotaviruses in very low birthweight, premature infants theoretically could increase the risk for adverse reactions from rotavirus vaccine. ACIP supports vaccination of prematurely born infants if they are aged at least 6 weeks, are being or have been discharged from the hospital nursery, and are clinically stable. Until further data are available, ACIP considers that the benefits of rotavirus vaccine vaccination of premature infants outweigh the theoretical risks. Remember that premature infants should be vaccinated according to chronological age; the age is not adjusted.

  3. If the first dose of rotavirus vaccine is administered to a 16-week old, should the other two doses be administered?

    Rotavirus vaccination should not be initiated for infants aged 13 weeks and older because there are insufficient data on safety of the first dose in older infants. However, ACIP recommends that when the first dose is inadvertently administered off-label at 13 weeks of age or older, the rest of the series should be completed as per the schedule, because the timing of the first dose should not affect the safety and efficacy of the second and third doses. Vaccine should not be administered after 32 weeks of age because of insufficient data on the safety and efficacy of rotavirus vaccine in infants after this age.

  4. What do you do if a child receives the first two doses of rotavirus vaccine on schedule, but doesn’t return on time for the 3rd dose at the recommended interval? Do you have to start over when they do come back?

    No you do not start the series over. There are minimum intervals between vaccine doses, but there are no maximum intervals. You just pick up where the child left off and complete the series, as long as you do not exceed the maximum age, which is 32 weeks. No doses should be administered once the child reaches 33 weeks of age, even if this means the child will not complete the series.

  5. If the rotavirus vaccine is removed from the package and is lying in a tray, is it still viable? The package insert states that it should be protected from light.

    Rotavirus vaccine is a live attenuated virus vaccine. Do not remove the foil package from the refrigerator until you are ready to administer the vaccine. If you are preparing several immunizations for the child, keep the rotavirus vaccine in the foil package to protect it from light until you are at the patient’s side and ready to administer the vaccine. Then remove the plastic tube from the foil pack and administer the vaccine.

  6. How should rotavirus vaccine plastic tubes or used tissues (if a child regurgitates some of the vaccine) be disposed of?

    Dispose of the plastic tubes or any other articles that may have virus on them as medical waste in a biohazard container.

  7. How do you remove the cap from the rotavirus plastic tube?

    There are instructions on the manufacturer’s website, and

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  1. If an adult has a history of pertussis infection as a child, is Tdap vaccine recommended for this person?

    Immunity from infection wanes just as immunity from immunization does.
    Adults with a history of pertussis generally should receive Tdap according to routine recommendations,

  2. Is there anything written that says you can give Tdap at a shorter than 5-year interval in the case of an outbreak?

    Yes. "Vaccine providers can administer Tdap to adolescents aged 11–18 years at an interval less than 5 years after Td, particularly when the benefit of providing protection against pertussis is likely to be increased. The safety of an interval as short as approximately 2 years between Td and Tdap is supported by a Canadian study among children and adolescents (see Spacing and Sequence Administration of Vaccines Containing Tetanus Toxoid, Diphtheria Toxoid, and Pertussis Antigens). . ." (Adolescent Recommendations:

    "Tdap may be given at an interval shorter than 10 years since receipt of the last dose of tetanus toxoid-containing vaccine to protect against pertussis. The safety of an interval as short as approximately 2 years between administration of Td and Tdap is supported by a Canadian study of children and adolescents. The dose of Tdap replaces the next scheduled booster dose of Td." (Provisional Adult Recommendations:

  3. If a healthcare worker receives Tdap and then is exposed to someone with pertussis, do you treat the healthcare worker prophylactically or consider the person immune.

    You would follow the post-exposure prophylaxis (PEP) protocol. There have been no changes in pertussis PEP with the licensure of Tdap. The vaccine is too new to make any changes until we have more data and know how Tdap may affect pertussis epidemiology in the U.S

  4. We recently had a pertussis outbreak with six confirmed cases ages 4 months, 7 months, 4 years, 13 years, 14 years, and 19 years. The 4-year-old had received all of his vaccines on time. Do you have any idea why he would have developed pertussis?

    Just as with any medication, no vaccine is 100% effective. There are multiple factors that could have been at play here. Not every individual responds the same to every vaccine. Perhaps one or more doses of the vaccine were not stored or administered properly. Perhaps the child had a large exposure (time or proximity or number of exposures).

  5. Can we administer Tdap now or should we wait for the ACIP adult recommendations to be published in the MMWR?

    The Tdap vaccines are approved for use now by the FDA. You are not required to wait for the ACIP recommendations to be published.

  6. If a woman received Td during pregnancy, do you then routinely give Tdap postpartum or wait until another Td is indicated?

    Pregnant women who previously have not received a dose of Tdap (including women who are breastfeeding) should receive Tdap after delivery, before discharge from the hospital or birthing center, if 2 years or more have elapsed since the last Td. Shorter intervals can be used (see "Special Situations" in the ACIP's provisional recommendations: If Tdap cannot be administered before discharge, it should be given as soon as feasible. The dose of Tdap replaces the next decennial dose of Td.

  7. If a child 7 through 9 years of age has an incomplete history or no history of DTaP, DT, or Td can you use Tdap?

    There is no Tdap vaccine approved by FDA or the ACIP for use in children 7 through 9 years of age. Td should be used. Appendix E of the ACIP Tdap Adolescent recommendations provides guidance in completing the series for children 7 through 10 years of age:

  8. If a child 10 years of age or older receives DTaP instead of Tdap, should the dose be repeated?

    No. If pediatric DTaP is inadvertently administered to an adolescent, the dose should be counted as the adolescent Tdap booster. The adolescent should receive the next dose of a vaccine containing tetanus and diphtheria toxoids 10 years after the inadvertent pediatric DTaP dose.

  9. Could you clarify the timeline for giving Tdap vaccine after someone has received the Td vaccine?

    The recommended interval between Td and Tdap for adolescents is 5 years and for adults it is 10 years. However, if there is a risk of pertussis or if the person will have contact with an infant younger than 12 months of age, then there is NO minimum interval. It is a risk (increased local reaction) vs. benefit (prevention of pertussis infection) situation that must be assessed by the provider. There are data suggesting that it is safe to give these two vaccines as close as 2 years apart, but they can be given even closer if the benefit outweighs the risk. The bottom line is that there is no minimum interval written in stone.

  10. Will Tdap vaccine replace the Td booster that is routinely recommended every 10 years?

    It is too early to know that. At this time Tdap is only approved for one dose.

  11. Is there a combination meningitis and tetanus vaccine?

    There is no combination meningococcal/tetanus vaccine. If you are referring to Hib meningitis, there is a combination Hib-DTaP vaccine known as TriHIBit.

  12. If an 11-year old received DT instead of Td, what do you do about the Tdap dose?

    Wait at least 2 years if possible to give the Tdap dose. However, if the patient is at increased risk of pertussis (e.g., pertussis outbreak, international travel, an infant younger than 12 months of age in the household) then there is no minimum interval. The patient should be warned that they could experience a stronger than normal local adverse reaction.

  13. Where can I find the poster “Check You Vials: Is it Tdap, DTaP, or Td?”

    This poster was developed by the California Immunization Program and is available from them at

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  1. Should you vaccinate someone who has already had the chickenpox?

    If a person has acceptable evidence of prior varicella zoster virus (VZV) infection, then vaccination is not necessary. Acceptable evidence of prior VZV infections includes:
    - Laboratory evidence of immunity or laboratory confirmation of disease;
    - Born in the US before 1980 (not acceptable for healthcare workers or pregnant women);
    - A healthcare provider diagnosis of varicella or healthcare provider verification of history of varicella disease; or
    - History of herpes zoster based on healthcare provider diagnosis.
    If there is any doubt, vaccinate. If the person is already immune, vaccination will not harm them. You will find a complete list for acceptable varicella immunity at

  2. What are the minimum intervals between doses of varicella vaccine for various age groups?

    For persons 12 months through 12 years of age the minimum interval between two doses of varicella vaccine is 12 weeks. However, if you discover on record review that the second dose was administered at least 4 weeks (28 days) after the first dose, the dose does not have to be repeated.
    For persons 13 years of age and older the minimum interval between two doses of varicella vaccine is 4 weeks (28 days).

  3. Should we draw titers on healthcare workers after varicella vaccination to verify immunity?

    Routine serologic testing for varicella immunity after administration of two doses of vaccine is not considered necessary because 99% of persons become seropositive after the second dose. Seroconversion, however, does not always result in full protection against disease. Institutional guidelines are needed for management of exposed vaccinees who do not have detectable antibody and for those who develop clinical varicella. A potentially effective strategy to identify persons who remain at risk for varicella is to test vaccinated persons for serologic evidence of immunity immediately after they are exposed to VZV. Prompt, sensitive, and specific serologic results can be obtained at reasonable cost with a commercially available latex agglutination (LA) test. Many other methods also have been used to detect antibody to VZV. The LA test can be completed in 15 minutes. Persons with detectable antibody are unlikely to become infected with varicella. Persons who do not have detectable antibody can be retested in 5–6 days. If an anamnestic response occurs, these persons are unlikely to contract the disease. HCWs who do not have antibody when retested may be furloughed. Alternatively, the clinical status of these persons may be monitored daily and they can be furloughed at the onset of manifestations of varicella.

  4. If a child had one dose of varicella vaccine and develops breakthrough infection, is the second varicella vaccine doses necessary?

    No, not if the rash illness is definitely known to be wild-type varicella infection. However, if there is any doubt, take the conservative approach and administer the second dose.

  5. Can MMRV be used if a person (adolescent or adult) presents with no evidence of immunity to measles, mumps, rubella, and varicella?

    No. MMRV vaccine is not approved for use in anyone 13 years of age or older.

  6. Do persons 13 years of age and older who previously received two doses of varicella vaccine now need a booster dose?

    No. Once a person receives two valid doses of varicella vaccine, there are no recommendations to give any further doses

  7. Can MMRV be used for the second varicella dose in persons 12 months through 12 years of age?

    Yes, as long as none of the components are contraindicated.

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  1. If a person has had a case of shingles, do you recommend the vaccine?

    The vaccine was not studied in persons who have already had shingles, and there are no recommendations to vaccinate them at this time. ACIP should be voting on recommendations for zoster vaccine in October, 2006.

    In general persons develop shingles only once because this infection boosts their immunity. Zoster vaccine is expected to provide that boost of immunity to persons who have not had shingles, thus allowing them to avoid the pain and unpleasantness of a shingles infection.

  2. Can someone younger than 60 years of age receive the zoster vaccine?

    FDA has only approved the vaccine for persons 60 years of age and older because that is the population in which the vaccine was studied. ACIP is expected to vote on zoster vaccine recommendations in October, 2006.

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