3-A. General Principles

This section addresses special situations for Tdap and Td use. As with the routine situations, only a single dose of Tdap should be administered to an adolescent aged 11-18 years. For most, but not all, of the special situations, Tdap is preferred to Td. In some special situations or when contraindications or precautions are present, Td rather than Tdap might be indicated. The dose of Td is 0.5 mL, administered intramuscularly.

Tdap (or Td) and MCV4 should be administered at the same visit during special situations if both vaccines are indicated and available, although this might not always be feasible (e.g., wound management). Simultaneous administration of Tdap (or Td) and MCV4 and an interval of at least 5 years between Td and Tdap can reduce the risk for local and systemic reactions. In certain special situations listed below, the benefit of protection against disease probably outweighs this risk.

3-B. Nonsimultaneous Vaccination with Tdap and Other Vaccines, Including MCV4

ACIP has recommended that inactivated vaccines can be administered at any time before or after a different inactivated or live vaccine (i.e., nonsimultaneous vaccination), unless a contraindication exists (Atkinson et al., 2002). Simultaneous administration of Tdap (or Td) and MCV4 (which all contain diphtheria toxoid) during the same visit is preferred when both Tdap (or Td) and MCV4 are indicated. If simultaneous vaccination is not feasible (e.g., a vaccine is not available), MCV4 and Tdap (or Td) can be administered using any sequence. Persons who recently received one diphtheria toxoid-containing vaccine might have increased rates of adverse reactions after a subsequent diphtheria toxoid-containing vaccine when diphtheria antibody titers remain elevated from the previous vaccination (Lloyd et al., 2003; Edsall et al., 1967; Relyveld, Bizzini, & Gupta, 1998; James, Longshore, & Hendry, 1951) (see "Safety Considerations for Adolescent Vaccination with Tdap or Td" section in the original guideline document for a discussion of nonsimultaneous vaccination).

3-C. Pertussis Outbreaks and Other Settings with Increased Risk for Pertussis or its Complications

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" in the original guideline document) (Halperin, et al., 2006).

The benefit of using Tdap at an interval less than 5 years after Td is likely to be increased among adolescents when the adolescent is at increased risk for acquiring pertussis (e.g., during outbreaks or periods of increased pertussis activity in the community). Postexposure chemoprophylaxis and other pertussis control guidelines are described elsewhere (CDC, 2000; American Academy of Pediatrics, 2003; Tiwari, Murphy, & Moran, 2005). The benefit of using a shorter interval also might be increased for adolescents with severe underlying medical conditions (e.g., chronic pulmonary disease or neurologic disorders), because these adolescents might be at increased risk for pertussis-related complications.

Infants aged <12 months are at highest risk for pertussis-related complications and hospitalizations compared with older age groups; young infants have the highest risk for death from pertussis. Administering Tdap at an interval less than 5 years after Td to an adolescent who has or anticipates having close contact with an infant aged <12 months might reduce the risk for transmitting pertussis to the infant. Infants should be vaccinated on time with pediatric DTaP ("Pertussis vaccination," 1997; CDC, 2006).

3-D. Lack of Availability of Tdap or MCV4

If Tdap and MCV4 are both indicated but only one vaccine is available, the available vaccine generally should be administered. When Tdap is indicated but not available, vaccine providers should administer Td or temporarily defer Tdap/Td vaccination. Td should be administered to provide protection against tetanus and diphtheria if the adolescent received the last pediatric DTP/DTaP/DT or Td >10 years earlier. Recommendations for use of Tdap among adolescents who already received Td would apply to these adolescents when Tdap becomes available (see "Routine Tdap Vaccination" [section 1-A in this summary]). Tdap/Td vaccination can be deferred temporarily if the adolescent completed the childhood DTP/DTaP vaccination series*, received the last pediatric DTP/DTaP/DT or Td <10 years earlier, and is likely to return for follow-up. If the vaccine provider defers Td in order to administer Tdap when it becomes available, a system to recall the adolescent should be maintained. The adolescent also can be referred to another facility for Tdap administration.

* Five doses of DTP/DTaP before seventh birthday; if the fourth dose was administered on or after the fourth birthday, the fifth dose is not needed.

3-E. Tetanus Prophylaxis in Wound Management

ACIP has recommended administering tetanus toxoid-containing vaccine and tetanus immune globulin (TIG) as part of standard wound management to prevent tetanus (see Table titled "Guide to tetanus prophylaxis in routine wound management among adolescents aged 11-18 years," below) ("Diphtheria, tetanus, and pertussis," 1991). Tdap is preferred to Td for adolescents aged 11-18 years who were vaccinated against tetanus >5 years earlier, require a tetanus toxoid-containing vaccine as part of wound management, and have not previously received Tdap. Adolescents who have completed the 3-dose primary tetanus vaccination series and have received a tetanus toxoid-containing vaccine <5 years earlier are protected against tetanus and do not require a tetanus toxoid-containing vaccine as part of wound management. Although MCV4 and Tdap (or Td) should be administered at the same visit during routine situations if both vaccines are indicated, this might not be feasible for wound management.

A thorough attempt must be made to determine whether an adolescent has completed the 3-dose primary tetanus vaccination series. Persons with unknown or uncertain tetanus vaccination histories should be considered to have had no previous doses of a tetanus toxoid-containing vaccine (see "Adolescents with History of Incomplete Pediatric DTP/DTaP/DT or Td Vaccination" [section 3-H] in this summary). Persons who have not completed the primary series might require a tetanus toxoid-containing vaccine and passive immunization with TIG at the time of wound management (see Table titled "Guide to tetanus prophylaxis in routine wound management among adolescents aged 11-18 years," below). When both TIG and a tetanus toxoid-containing vaccine are indicated, each product should be administered using a separate syringe at different anatomic sites ("Diphtheria, tetanus, and pertussis," 1991).

Adolescents with a history of an Arthus reaction after a previous dose of a tetanus toxoid-containing vaccine should not receive a tetanus toxoid-containing vaccine until >10 years after the most recent dose, even if they have a wound that is neither clean nor minor. If the Arthus reaction was associated with a vaccine that contained diphtheria toxoid without tetanus toxoid (e.g., MCV4), deferring Tdap or Td might leave the adolescent inadequately protected against tetanus and TT should be administered. In all circumstances, the decision to administer TIG is based on the primary vaccination history for tetanus.

Table. Guide to tetanus prophylaxis in routine wound management among adolescents aged 11-18 years

¹ Such as, but not limited to, wounds contaminated with dirt, feces, soil, and saliva; puncture wounds; avulsions; and wounds resulting from missiles, crushing, burrs, and frostbite
² Tdap is preferred to Td for adolescents who have never received Tdap. Td is preferred to TT for adolescents who received Tdap previously or when Tdap is not available (if TT and TIG are both used, Tetanus Toxoid Adsorbed rather than Tetanus Toxoid for Booster Use Only [fluid vaccine] should be used).
³ Yes, if >10 years since the last tetanus toxoid-containing vaccine dose
⁴ Yes, if >5 years since the last tetanus toxoid-containing vaccine dose (see original guideline document for discussion of Arthus reactions)

3-F. History of Pertussis

Adolescents aged 11-18 years who have a history of pertussis generally should receive Tdap according to the routine recommendations. This practice is preferred because duration of protection induced by pertussis is unknown (waning immunity might begin as early as 7 years after infection) and because the diagnosis of pertussis can be difficult to confirm, particularly with test results other than positive culture for Bordetella pertussis (Wendelboe et al., 2005). Administering pertussis vaccines to persons with a history of pertussis presents no theoretical safety concern.

3-G. Adolescents with History of Incomplete Pertussis Vaccination (Received Pediatric DT or Td Instead of Pediatric DTP/DTaP)

Adolescents who received pediatric DT or Td vaccination instead of one or more doses of pediatric DTP/DTaP in the series during childhood should generally receive a single dose of Tdap to provide protection against pertussis if they completed the recommended childhood vaccination series for tetanus and diphtheria* and have no contraindications to the pertussis components. In routine situations, an interval of at least 5 years between Td and Tdap is encouraged (see "Routine Tdap Vaccination" [section 1-A in this summary]).

*Five doses of pediatric DTP/DTaP/DT before the seventh birthday; if the fourth dose was administered on or after the fourth birthday, the fifth dose is not needed. Children who began the tetanus and diphtheria vaccination series at age >7 years required 3 doses of Td to complete the primary series.

3-H. Adolescents with History of Incomplete Pediatric DTP/DTaP/DT or Td Vaccination

Adolescents aged 11-18 years who have never been vaccinated against tetanus, diphtheria, or pertussis (no doses of pediatric DTP/DTaP/DT or Td) should receive a series of three tetanus and diphtheria toxoid-containing vaccinations. The preferred schedule is a single Tdap dose, followed by a dose of Td >4 weeks after the Tdap dose, and a second dose of Td 6-12 months after the earlier Td dose. Tdap can be substituted for any one of the three Td doses in the series.

Adolescents who received other incomplete vaccination schedules for tetanus and diphtheria should be vaccinated with Tdap and/or Td according to guidance for catch-up vaccination. A single dose of Tdap can be used to substitute for any one of the Td doses in the series.

In situations in which the adolescent probably has received vaccination against tetanus and diphtheria but cannot produce records, vaccine providers can obtain serologic testing for antibodies to tetanus and diphtheria to avoid unnecessary vaccination. If antitetanus and antidiphtheria levels are each >0.1 IU/mL, previous vaccination with tetanus and diphtheria toxoid--containing vaccines is likely and a single dose of Tdap is indicated; this Tdap dose counts as the adolescent booster dose.

3-I. Children Aged 7-10 Years with Incomplete Pediatric DTP/DTaP Vaccination History

Neither Tdap vaccine is licensed for use in children aged <10 years (Food and Drug Administration [FDA], 2006, 2005). Children aged 7-10 years who never received a pediatric DTP/DTaP/DT dose or a Td dose generally should receive 3 doses of Td*; dose 2 is administered >4 weeks after dose 1 and dose 3 is administered 6-12 months after dose 2. Children aged 7-10 years who received other incomplete vaccination schedules against tetanus, diphtheria, and pertussis should be vaccinated according to catch-up guidance. When these children become adolescents (aged 11-18 years), they should receive Tdap according to the routine recommendations and interval guidance used for adolescents who completed the childhood DTP/DTaP series (see "Routine Tdap Vaccination" [section 1-A in this summary]).

* A single dose of BOOSTRIX® Tdap is licensed for persons aged 10 years and can be used instead of Td for one of the doses in children aged 10 years; if BOOSTRIX® is administered early to a child aged 10 years, the dose counts as the adolescent Tdap dose usually administered at age 11-12 years.

In situations in which the child probably has received vaccination against tetanus and diphtheria but cannot produce records, vaccine providers can obtain serologic testing for antibodies to tetanus and diphtheria to avoid unnecessary vaccination. If antitetanus and antidiphtheria levels are each >0.1 IU/mL, previous vaccination with tetanus and diphtheria toxoid-containing vaccines is likely. In this situation, Td vaccination can be deferred until the child is aged 11-12 years and eligible to receive Tdap.

3-J. Inadvertent Administration of Tdap or Pediatric DTaP

To help prevent inadvertent administration of Tdap when pediatric DTaP is indicated or pediatric DTaP when Tdap is indicated, vaccine providers should review product labels before administering these vaccines; the packaging might appear similar. Tdap is not indicated for children aged <10 years. Tdap contains lower amounts of diphtheria toxoid and lower amounts of some pertussis antigens compared with pediatric DTaP. Studies of the immune responses to Tdap among infants have not been conducted. Pediatric DTaP is not indicated for persons aged >7 years; the increased diphtheria toxoid content is associated with higher rates of adverse reactions in older persons ("Diphtheria, tetanus, and pertussis," 1991; Ipsen, 1954; Lloyd et al., 2003; Macko & Powell, 1985; Rennels et al., 2000).

Guidance on the best approach to vaccination following inadvertent administration of Tdap or pediatric DTaP is based primarily on expert opinion. The family should be informed of any inadvertent vaccine administration. Adverse events associated with inadvertent vaccine administration can be reported to VAERS (see "Reporting of Adverse Events after Vaccination" in this summary). If Tdap is inadvertently administered instead of pediatric DTaP to a child aged <7 years as any one of the first three doses of the tetanus-diphtheria-pertussis vaccination series, the Tdap dose should not be counted as valid, and a replacement dose of pediatric DTaP should be administered. If the inadvertent administration is discovered while the child is in the office, the pediatric DTaP can be administered during the same visit. If the child has left the office, some experts suggest administering the replacement dose of pediatric DTaP within approximately 72 hours, or administering it 4 weeks later to optimize the child's immune response to the antigens in pediatric DTaP. This practice helps ensure that the child stays on the primary series schedule and has adequate protection against diphtheria and pertussis. However, the replacement dose of pediatric DTaP can be administered as soon as feasible at any interval after the inadvertent Tdap dose. The remaining doses of the pediatric DTaP series should be administered on the routine schedule, with at least a 4 week interval between the replacement dose of pediatric DTaP and the next dose of pediatric DTaP. For example, if an 8-week-old infant inadvertently received a dose of Tdap instead of the first dose of pediatric DTaP and does not receive a replacement dose of pediatric DTaP within about 72 hours, a replacement dose of pediatric DTaP can be administered 4 weeks after the inadvertent Tdap dose (age 12 weeks). The routine schedule of pediatric DTaP can then be resumed 4 weeks after the pediatric DTaP replacement dose (age 16 weeks) with the other recommended vaccines ("Pertussis vaccination," 1997; CDC, 2006).

If Tdap is inadvertently administered as the fourth or the fifth dose in the tetanus-diphtheria-pertussis vaccination series to a child aged <7 years, the Tdap dose should be counted as valid and does not need to be repeated; the child who received Tdap as a fourth dose should complete the pediatric DTaP schedule (CDC, 2006). The routine adolescent Tdap vaccination recommendations would apply when this child becomes an adolescent. For example, a child who inadvertently receives Tdap at age 5 years instead of the fifth dose of pediatric DTaP should receive a second dose of Tdap at age 11-12 years.

If Tdap or pediatric DTaP is inadvertently administered to a child aged 7-9 years instead of Td as part of catch-up vaccination or for wound management, this dose can be counted as the adolescent Tdap dose, or the child can later receive an adolescent booster dose of Tdap according to the interval guidance used for Td to Tdap (see "Routine Tdap Vaccination" [section 1-A in this summary] and "Pertussis Outbreaks and Other Settings with Increased Risk for Pertussis or its Complications" [section 3-C in this summary]). In either case, the child should receive a dose of vaccine containing tetanus and diphtheria toxoids no longer than 10 years after the inadvertent Tdap or pediatric DTaP dose or according to the guidance for catch-up vaccination (see Table titled "Guide to catch-up vaccination with Td for children aged 7-10 years," below).

If pediatric DTaP is inadvertently administered to an adolescent aged 11-18 years, 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 or according to the guidance for catch-up vaccination (see Table titled "Guide to catch-up vaccination with Td and Tdap for adolescents aged 11-18 years," below).

Table. Guide to catch-up vaccination with Td for children aged 7-10 years¹

¹ Td is recommended for children aged 7-10 years; a single dose of BOOSTRIX® Tdap vaccine is licensed for persons aged 10 years and can be used instead of Td for one of the doses in children aged 10 years. If BOOSTRIX® is administered to a child aged 10 years, the dose counts as the adolescent Tdap dose. Pediatric DTP/DTaP/TD vaccines are not indicated for persons aged >7 years. See Appendix F in the original guideline document for a complete list of vaccine abbreviations.
² Number of doses and the minimum intervals between the last dose administered and the next dose of tetanus and diphtheria toxoid-containing vaccine needed to provide protection against tetanus and diphtheria.
³ Not applicable.
⁴ These children should receive Tdap to provide protection against tetanus, diphtheria, and pertussis according to the routine vaccination recommendations for adolescents who completed the pediatric DTP/DTaP series, when they become adolescents aged 11-18 years; an interval of at least 5 years between Td and Tdap is encouraged, but shorter intervals can be used (see "Routine Tdap Vaccination" [1-A] in this summary).
⁵ Some experts suggest administering a dose of Td now to children aged 7-10 years with this vaccination history if no dose of a tetanus and diphtheria toxoid-containing vaccine was administered at age >4.

Table. Guide to catch-up vaccination with Td and Tdap for adolescents aged 11-18 years¹

¹ Adolescents aged 11-18 years with incomplete vaccination schedules for tetanus and diphtheria should receive a single dose of Tdap as part of catch-up vaccination if they have not received Tdap to add protection against pertussis; Td should be used for other doses if indicated (see "Routine Tdap Vaccination" [1-A] in this summary). Pediatric DTaP/DTP/DT vaccines are not indicated for persons aged >7 years. See Appendix F in the original guideline document for a complete list of vaccine abbreviations.
² Number of doses and the minimum intervals between the last dose administered and the next dose of tetanus and diphtheria toxoid-containing vaccine needed to provide protection against tetanus and diphtheria.
³ Not applicable.
⁴ To maintain protection against tetanus and diphtheria, a tetanus and diphtheria toxoid-containing vaccine is indicated 10 years after the last adolescent dose.
⁵ If the adolescent has not received Tdap as one of the doses, a single dose of Tdap is encouraged to add protection against pertussis; an interval of at least 5 years between Td and Tdap is encouraged but shorter intervals can be used (see "Routine Tdap Vaccination" [1-A] in this summary).

3-K. Vaccination during Pregnancy

As with other inactivated vaccines and toxoids (Atkinson et al., 2002; CDC, "Guidelines for vaccinating pregnant women," 2005), pregnancy is not considered a contraindication for Tdap vaccination. Guidance on the use of Tdap during pregnancy to protect against pertussis is under consideration by ACIP. Pregnant adolescents who received the last tetanus toxoid-containing vaccine <10 years previously should generally receive Tdap after delivery, if otherwise indicated (see "Post-Partum Vaccination" [section 3-L] in this summary).

To prevent neonatal tetanus, pregnant adolescents who received the last tetanus toxoid-containing vaccine >10 years previously should generally receive Td in preference to Tdap. ACIP has recommended that pregnant women receive Td if the last tetanus toxoid-containing vaccine was administered >10 years previously ("Diphtheria, tetanus, and pertussis," 1991; CDC, "Recommended adult immunization schedule, 2005; Atkinson et al., 2002; CDC, "Guidelines for vaccinating pregnant women," 2005). If Td is indicated, vaccinating during the second or third trimester is preferred when feasible to minimize a perception of an association of vaccine with adverse pregnancy outcomes, which are more common during the first trimester. A pregnant adolescent who has not received the 3-dose primary tetanus vaccination series should begin this series during pregnancy, using Td. (see "Adolescents with History of Incomplete Pediatric DTP/DTaP/DT or Td Vaccination" [section 3-H] in this summary).

Because of lack of data on the use of Tdap in pregnant women, both Tdap manufacturers have established pregnancy registries. Health-care providers are encouraged to report Tdap vaccination during pregnancy to the following registries: BOOSTRIX® to GlaxoSmithKline Biologicals at 1-888-825-5249 and ADACEL™ to sanofi pasteur at 1-800-822-2463 (1-800-VACCINE) (FDA, 2006; FDA, 2005).

3-L. Post-Partum Vaccination

Adolescents aged 11-18 years, including those who are breastfeeding, should receive a single dose of Tdap as soon as feasible in the postpartum period, according to the routine Tdap recommendations and interval guidance (see "Routine Tdap Vaccination" [section 1-A] in this summary and "Pertussis Outbreaks and Other Settings with Increased Risk for Pertussis or its Complications" [section 3-C] in this summary). For adolescent mothers who have not already received Tdap, vaccinating the mother with Tdap during the postpartum period might reduce the risk for pertussis transmission to the infant. Protection of the mother against pertussis requires an estimated 1 to 2 weeks after vaccination.

3-M. Older Adolescents and Adults Aged >18 Years

To maintain protection against tetanus and diphtheria, ACIP has recommended decennial Td boosters for adults beginning 10 years after the adolescent dose ("Diphtheria, tetanus, and pertussis," 1991; "Immunization of adolescents," 1996). The safety and efficacy of Tdap (ADACEL™) as a single dose booster immunization against tetanus, diphtheria, and pertussis has been demonstrated for persons aged 19-64 years (FDA, 2006). In October 2005, ACIP recommended a single dose of Tdap (ADACEL™) for adults aged 19-64 years who have not received Tdap; recommendations for the use of Tdap among adults will be published separately.****