Vaccines and Preventable Diseases:

Combined Vaccines DTaP / DT / Td / Tdap - Submitted Q&A
Questions submitted during immunization satellite broadcasts or through NIPINFO

General Questions

• We have had several cases of pertussis in our county. Most of these cases have been in very young children under one year of age who have had only one or two doses of DTaP. How much protection does one or two doses offer?
  
  There isn’t much data on the efficacy and protection from one or two doses of DTaP. Pertussis vaccine trials are difficult to do. Virtually everyone who has looked at this issue uses 3 doses as the benchmark. We know that with 3 doses efficacy is 80%-85%. We know that two doses are better than one, and one dose is better than none. But I don’t know of any data that would give us a feeling of how well one or two doses would protect against pertussis. (2/20/03) More Information
  

• If a person has culture-confirmed pertussis, are they immune for life? If they have not completed their DTaP series, do they need additional doses of DTaP or DT?
  
  ACIP states that if you have had culture-confirmed pertussis, which probably applies to PCR as will, then you are considered immune. You are immune for a long time, but immunity for a lifetime is questionable. There is evidence that pertussis has occurred in adults who had pertussis as children.
  
  Additional doses of pertussis-containing vaccine are not recommended for these individuals. However, you do not need to stock DT just for these patients. I don’t know of any data regarding increased risk of side effects if pertussis-containing vaccine is administered to someone who has had pertussis. Probably the most that would happen is an additional local reaction. If there is any doubt, err on the side of caution and vaccinate. (2/20/03)

• A mother brings a 2½ year old child to the clinic with no history of immunizations. The mother states the child has recovered from a cough that sounds much like pertussis. The mother insists on only one shot and is very fearful of that. What vaccine would you administer in this situation?
  
  The mother's memory is not acceptable evidence of immunity. Young children are at increased risk for pertussis. Therefore we would recommend a dose of DTaP, although one dose won’t offer much protection. It also sounds like education and follow-up are certainly indicated with this mother and child. (2/20/03)
  

• What precautions should be followed for newborns when the mother has not been immunized against tetanus since her childhood series?
  
  The mother should be educated about the risk of tetanus, especially regarding care of the cord stump and circumcision (if applicable). Some cultures use “belly bands” or earth-based healing compounds. It is extremely important to caution these mothers about keeping these sites clean and not introducing dirt/feces into the site. These infants, who have little or no protection from maternal antibodies, should begin their DTaP series at the earliest possible age, which is 6 weeks. ACIP DTP Recommendations (2/20/03)
  

• A nurse on our staff inadvertently administered Td intradermally instead of the PPD that should have been given. The patient experienced a red blister-like area at the injection site with burning and itching which lasted several months. It subsided over a 6-month period, but even now there is a cyst-like lump in the injection area. Can she receive a PPD on her other arm and a tetanus shot administered at the correct site? Also, what are the ramifications of having that dose given in the wrong way?
  
  I wish we could say this is uncommon, but unfortunately we hear about situations like this too often. You should not count the Td dose that was given by the intradermal route. The patient probably received only 0.1 mL of Td, which is a very small fraction of a dose.
  
  Td is locally very reactogenic. That is why it is given intramuscularly. Local reactions can be expected if it is administered intradermally.
  
  The patient should receive a repeat dose of Td now, and then should receive her Td boosters on schedule. The PPD should be given in the other arm or distal to the area where the incorrect dose was given. She should be O.K. Presumably the inflammation will go away with time, but there may be a scar that will hopefully also resolve over time. (2/20/03)

• Is it O.K. to administer tetanus vaccine to a pregnant woman. The package insert says no unless there is an incident.
  
  Td toxoid is an inactivated vaccine and is indicated routinely for pregnant women. Previously vaccinated pregnant women who have not received a Td vaccination within the last 10 years should receive a booster dose. Pregnant women who are not immunized or only partially immunized against tetanus should complete the primary series. You don’t want to risk an infant being born without maternal antibodies and susceptible to neonatal tetanus. Although no evidence exists that tetanus and diphtheria toxoids are teratogenic, some providers prefer waiting until the second trimester of pregnancy to administer Td to minimize any concern about the theoretical possibility of such reactions. Although Td is preferred, Tdap may be administered during pregnancy in certain circumstances. For more information, see the ACIP's provisional recommendations on prevention of tetanus, diphtheria and pertussis among pregnant women. (8/24/07)

• A patient who was recently vaccinated with tetanus toxoid (TT) is planning to travel to Russia and needs diphtheria protection. What should we do?
  
  We advise that you vaccinate the person with Td, or Tdap if appropriate, so that they will have protection against diphtheria. You should tell this person that their arm may be more sore than usual. If this person were going to stay in the U.S., we would recommend that you just wait until their next routine booster to give Td. (2/20/03)

• If patients in a nursing home can't remember if they have had Td, should we start vaccinating them?
  
  A dose is only valid if it's documented. If you don't know what they have, then, yes, you have to repeat the series or initiate the series, and make sure it's documented. ACIP General Recommendations (8/24/07)

• If there is no diphtheria or very little of it in this country, why do we even bother vaccinating against it?
  
  You don't have to go very far to be at risk for diphtheria. A January 2004 MMWR article describes the case of a Pennsylvania man who traveled to Haiti for a weekend to help build a church in a rural area. He came back to the United States ill with diphtheria and eventually died. Also, diphtheria can be imported at any time. Just because it is not common in the United States does not mean it can't occur. We should all be protected from diphtheria with a booster every 10 years. (02/26/04)

• 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). (9/10/06)

Combinations

• Since we are now giving COMVAX at 1 year of age, do we still need to make sure the DTaP #3 and Prevnar are given at 6 months exactly or can they be given earlier than 6 months of age as long as we observe the minimum intervals? Example: DTaP #1 at 6 weeks of age, DTaP #2 at 3 months of age, and DTaP #3 at 5-6 months of age?
  
  There has been no change in the recommended schedules for DTaP and Prevnar. Clinical studies have reported that recommended ages and intervals between doses of multidose antigens provide optimal protection or have the best evidence of efficacy. Minimum ages and intervals between doses should only be used when there is some reason to accelerate the schedule, such as when a child is behind schedule or there is impending international travel. The introduction of COMVAX has not changed these recommendations. (2/20/03)

• Can you interchange Pediarix with other DTaP vaccines for the primary doses in the schedule?
  
  ACIP’s position is that, if possible, you should use the same brand of DTaP for all doses in the series. This same recommendation is made in the AAP Red Book. That means if Pediarix has been used, it would be preferable to use Infanrix for the 4th and 5th DTaP doses, or for the 2nd or 3rd DTaP doses if Pediarix is not available (remember, Infanrix is the DTaP component in Pediarix).
  
  However, if you do not have the same brand or you do not know what brand was used, you can use another DTaP vaccine to complete the first 3 doses in the primary series or to complete the 4th and 5th DTaP doses. This includes the use of TriHIBit for the 4th dose. (02/26/04)

• Why does TriHIBit exist? It causes confusion because most immunization records don’t indicate if a child received TriHIBit or single-antigen Hib for the primary series.
  
  Vaccine manufacturers can build any kind of vaccine they want. CDC does not control this. It is not that children receive no protection from the Hib component of TriHIBit if they receive it as doses 1-3, but the response is less than that of single-antigen Hib vaccine. To be licensed, FDA requires that the components of a combination vaccine perform as well or better than their single-antigen counterparts. We recommend that if you know a child received TriHIBit as part of the primary series, the Hib doses should be repeated. Hopefully, a future version of the vaccine will meet the FDA criteria and will be available for all 4 doses. (2/20/03)

• If the first 3 doses of DTaP are given as TriHIBit, do they count as valid?
  
  TriHIBit is licensed only for the 4th dose in the DTaP/Hib series. If you encounter a child who received TriHIBit for one or more of the first three doses of the series, you can count the DTaP doses as valid as long as the minimum age and minimum intervals were observed. You should revaccinate the child with single antigen Hib vaccine appropriate for the child’s age. (2/26/03)

• If we use only Infanrix for doses 1 through 5 are we wrong? Do we need to stock Tripedia for the fifth dose?
  
  No, you are not wrong. You should use what you have in stock. If all you have is Infanrix and someone is eligible for the fifth dose, ACIP has recommended that you use what you have. There really isn't a concern about the safety or efficacy. There are just not extensive data. Certainly don't send the child out without being vaccinated, and you don't need to stock certain vaccines for certain doses. (2/20/03)

• 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.

  (9/10/06)

Schedule/Intervals

• A 7 month old child received the 4th DTaP 6 weeks after the 3rd DTaP and the 4th dose of Hib at the same time. Does this child require any repeated doses?
  
  Yes, the 4th doses of DTaP and Hib should not be administered before the 1st birthday. Also, there should be a minimum of 2 months between the 3rd and 4th doses of Hib, and 6 months between the 3rd and 4th doses of DTaP. Doses administered 5 or more days earlier than these minimum intervals or ages should be repeated as age-appropriate. The repeat doses should be spaced after the invalid doses by the recommended minimum interval as shown in Table 1 of the ACIP General Recommendations on Immunization. ACIP General Recommendations (2/20/03)

• A child receives the first 3 doses of DTaP on time and then does not return until just before the 4th birthday. Should we give a dose now and another in 6 months or wait until they turn 4 years and give one more dose?
  
  Do not wait. Give a dose now and the 5th dose later. There should be at least 6 months between the 4th and 5th doses, DTP ACIP Recommendations (see Table 1 & “Primary Vaccination”). (2/20/03)

• If a 17-month-old child has received five doses of DTaP, but two doses were invalid because of interval problems, how many doses will this child need?
  
  The child will need two more doses. The 6 doses before 7 years of age rule applies to valid doses. The concern about the number of doses is the risk of an Arthus reaction (an exaggerated local reaction in the limb where the injection is administered). This can happen when too many doses of tetanus- and diphtheria-containing vaccines are given too close together. However, it is important to ensure that the child has adequate protection against pertussis. Any time you go beyond the 6 doses, as in this situation, you should at least explain carefully to the parents that the child could have a stronger-than-usual local reaction, but that the extra doses are necessary for protection against pertussis. Preparing them for the possibility of such a reaction, and telling them how to take care of it, could help them handle it better if it occurs. (02/26/04)

• An autistic child has not had any of the primary immunizations but receives a dose of Td when injured. This child has had two doses of Td four years apart. How much protection would this child have?
  
  The immune system doesn’t forget, so the child has the benefit of immune memory from the first two doses, but needs the 3rd primary dose for adequate immunity, as well as routine boosters since immunity does wane with time. Hopefully you can convince the parent to give the protection that vaccines offer. (2/20/03)

• A 14-year-old received one dose of DTaP at 6 years of age. How many Td doses are needed to complete the series?
  
  Because the dose was administered after one year of age, the primary series should consist of 3 doses. This child needs 2 doses to complete the series, spaced at least 6 months apart. One of these doses should be Tdap, and the other Td. After that, a routine booster of Td should be given every 10 years. Tdap ACIP Recommendations for Adolescents (See page 26 and Appendix D) (2/20/03, updated 9/17/07)

• My patient was given single antigen tetanus rather than Td. Should I revaccinate? If so, when?
  
  With the licensure of Tdap the answer to this question changes. When the alternative to tetanus toxoid (TT) was Td, we recommended waiting until the next 10-year booster, unless the patient was planning international travel. Now that Tdap is available, ACIP recommends that a dose of Tdap may be given 5 years after the last dose of Td for adolescents or adults who have not gotten a dose of Tdap. The same interval would apply after an inadvertently administered dose of TT. A shorter interval is acceptable if the patient is at increased risk for pertussis, or has close contact with an infant younger than 12 months of age. Remember that Tdap is not licensed for children younger than 10. ACIP Tdap Recommendations for Adolescents ACIP Tdap Recommendations for Adults (6/26/03, updated 9/17/07)

• Please clarify on the minimum interval table in Appendix A of the Pink Book, the minimum interval between DTaP #3 and DTaP #4. Is it 6 months or 4 months?
  
  This refers to "Recommended and Minimum Ages and Intervals Between Vaccine Doses” (which also appears in the ACIP "General Recommendations"). This table says there is a 6 month interval between the 3rd and 4th doses and the minimum age for the 4th dose is 12 months of age. However, the 5th footnote says that a 4th dose given >4 months after the 3rd dose needn't be repeated.
  
  The issue is when should you schedule the 4th dose vs. when can you count a 4th dose as valid after it has been given. Ideally, the 4th dose should be scheduled 6 to 12 months after the 3rd dose, which is the RECOMMENDED interval, and it should always be given after the 1st birthday.
  
  However, a few years ago we ran into a situation where some children had gotten the 4th DTaP sooner than 6 months after the 3rd dose. We took this issue to the ACIP. The committee felt the benefit of revaccinating those children was not worth the risk of local reactions from having too many DTaP close together. Therefore, if on a record review you find someone who received a 4th dose of DTaP on or after the first birthday and the dose was AT LEAST 4 months after the 3rd dose, you don't have to repeat it. The main thing to remember is when you schedule doses; don't schedule them for 4 months apart. You need to schedule the 4th dose 6 to 12 months after the 3rd dose and the child must be at least 12 months of age. (02/20/04)

• DAPTACEL™ has not been approved for the 5th DTaP dose. What are the ramifications and/or implications of using it for this dose?
  
  From time to time ACIP will make “off-label” recommendations for a vaccine based on data the committee has available beyond the data that was obtained during clinical trials and presented to the FDA when the vaccine was licensed. This is one such case. ACIP recommends that it is preferable to complete the 5-dose DTaP series with the same vaccine based on available safety and efficacy data. ACIP also recommends that if DAPTACEL is the only DTaP you have on hand and a child presents for the 5th dose, it is better to use the vaccine you have on hand than to miss the opportunity to vaccinate. (03/04/04)

Wound Management

• Is a Td booster still recommended for dirty injuries if the last documented Td is more than 5 yrs old?
  
  Yes. Recommendations for wound management have not changed, except that they now include Tdap for patients who have never received Tdap. ACIP Tdap Recommendations for Adults (page 25 & Table 14) (6/26/03, updated 9/18/07)

• How long can a person wait after a wound to get a Td booster?
  
  There is no simple answer to your question. The urgency of tetanus prophylaxis is a function of several factors, including the nature and location of the wound and the person's previous vaccination status.
  
  The incubation period of tetanus can be as short as 1 day, or as long as several months. Most cases occur within 3 days to 3 weeks of the injury. Once the disease starts it must run its course.
  
  Factors that increase the urgency of prophylaxis include lack of prior vaccination with tetanus toxoid, or vaccination in the remote past without a booster dose within the last 10-20 years; unknown vaccination status (you should always assume the worst case scenario, i.e., that the person is unvaccinated unless they can prove otherwise); and a wound contaminated with dirt or feces. The situation is most urgent when the person is unvaccinated or inadequately vaccinated, and the wound is contaminated and on or near the head. Puncture wounds are dangerous because of the anaerobic condition that results.
  
  Factors that reduce the urgency are evidence of primary vaccination with a booster dose within the prior 10-20 years, or a clean wound (i.e., uncontaminated with dirt or feces).
  
  The decision whether or not to recommend an ED visit is a judgment call by the person doing the triage. Tetanus is unlikely (but not impossible) to result from a clean wound in a person who has been vaccinated. The other end of the scale (come in right now) is an unvaccinated person with a dirty head puncture wound. We don't know of any formula or algorithm to guide the urgency level for situations that lie between these two extremes. If there is any doubt about the person's vaccination status, get them in sooner rather than later. Puncture and contaminated wounds need to be seen immediately for treatment of the wound itself. And because the incubation period of tetanus can be very long, it is never "too late" to receive prophylaxis. (6/26/03)

Tdap

• 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, http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5517a1.htm?s_cid=rr5517a1_e (9/10/06)

• 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). . ." (ACIP Tdap Recommendations for Adolescents) .
  
  "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." (ACIP Tdap Recommendations for Adults) (9/10/06)

• 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. (9/10/06)

• 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 for Tdap during pregnancy). 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. (9/10/06)

• 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: www.cdc.gov/mmwr/PDF/rr/rr5503.pdf (9/10/06)

• 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 patient should receive the next dose of a tetanus/diphtheria-containing vaccine after the usual 10-year interval. www.cdc.gov/mmwr/PDF/rr/rr5503.pdf (9/10/06)

• 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. (9/10/06)

• 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. (9/10/06)

• 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. (9/10/06)

• Where can I find the poster “Check Your Vials: Is it Tdap, DTaP, or Td?”
  
  This poster was developed by the California Immunization Program and is available from them at www.dhs.ca.gov/ps/dcdc/izgroup/pdf/IMM-508.pdf (exit) (9/10/06)

Additional Information

Pertussis in the Community

In a situation where you have pertussis in the community, one thing that should be done is to try to get the vaccine into the children as quickly as you can, particularly young infants who are by far the most likely to have complications or die from pertussis. You can accelerate the pertussis vaccine schedule to 6, 10, and 14 weeks of age, using the minimum age and intervals to get doses in as early as possible. Don’t let any infants fall behind if there is pertussis in your community. You definitely have a problem if you have adults with persistent coughs caring for infants. They may have undiagnosed pertussis and can act as a source of infection in the infants. If you have pertussis cases in your area, you can put out some kind of alert for adults, particularly those around children, to get treatment and stay away from young children if they have a persistent cough. Pertussis outbreaks are difficult to deal with because the disease can circulate among adults and older children. This situation may improve, now that we have pertussis vaccines that can be administered to adolescents and adults. (8/24/07)

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