The Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention, in a unanimous 14-0 vote, recommended either tetanus, diphtheria, and acellular pertussis (Tdap) or tetanus and diphtheria (Td) vaccines for decennial (every 10 years) Td vaccination, tetanus prophylaxis in the setting of wound prophylaxis, and catch-up immunizations in those aged 7 years or older. The current recommendations advise giving only the Td vaccine, which does not protect against pertussis, for these indications, according to information presented at a meeting yesterday. The committee also voted unanimously to recommend the same changes to the Childhood Immunization Schedule. The Tdap vaccine is more expensive; however, the proposed changes will allow healthcare providers additional flexibility by giving patients and providers more choices. "Although data were limited, the randomized controlled trial that compared Tdap and Td for the three-dose series was reassuring, as were other published and unpublished data [presented at the meeting]," Fiona Havers, MD, MHS, National Center for Immunization and Respiratory Diseases, said during a presentation. "The work group also noted there were no concerning safety signal in multiple sources of data, including in pregnant women, although data are sparse on multiple doses of Tdap in a single pregnancy and [the group noted] that there is need for continued safety monitoring," Havers added. Children aged 7 to 18 years and adults aged 19 years or older who are unvaccinated against pertussis, tetanus, or diphtheria should be given a series of three tetanus and diphtheria toxoid-containing vaccines, at least one of which should be Tdap. "The preferred schedule is a dose of Tdap, followed by a dose of either Td or Tdap at least 4 weeks afterward and another dose of either Td or Tdap 6 to 12 months later," the committee recommends. Children who receive a dose of Tdap at age 7 to 9 years should be given an adolescent dose of Tdap at age 11 to 12 years. Children who receive a dose of Tdap at age 10 years or older do not need a repeat dose. For those aged 11 to 18 years, ACIP now recommends a single dose of Tdap given during a preventive care visit at the age of 11 to 12 years, followed by a booster dose of Td or Tdap every 10 years throughout life. Children aged 7 to 18 years and adults aged 19 years or older who are not completely immunized against pertussis, tetanus, and diphtheria should be given one dose of Tdap during the catch-up series, preferably for the first dose. Patients who require additional doses of tetanus toxoid-containing vaccine can be given either Td or Tdap vaccine. In the setting of wound prophylaxis for patients requiring tetanus prophylaxis, nonpregnant individuals with documented prior receipt of Tdap may be given either Td or Tdap. For catch-up immunization and tetanus prophylaxis in pregnant women and neonates, the panel recommends unimmunized women receive two or more properly spaced doses of tetanus toxoid-containing vaccine prenatally, one of which should be Tdap. Pregnant women needing more than one dose of tetanus vaccine can receive either Td or Tdap vaccine for those doses. "She should complete the three-dose primary series at the recommended intervals," the panel recommends. Closely Spaced Doses With respect to closely spaced Tdap doses, published research found no unusual or increased occurrence of adverse events when patients received either Tdap or Td as a second or third dose. No differences in reactogenicity were seen for regimens resembling the current and proposed catch-up schedule. "While data on multiple Tdap doses is limited, our review of published and unpublished safety data is reassuring," Pedro Moro, MD, National Center for Emerging and Zoonotic Infectious Diseases, CDC, said in a presentation at the meeting. Unpublished data from reports submitted to the Vaccine Adverse Event Reporting System (VAERS) found that from January 1, 1990 to June 30, 2019, 342 of 34,804 reports involved multiple doses of Tdap — 88 involved an interval of 12 months or fewer between doses. Of those, 67 (76.1%) were vaccination errors and 21 (23.9%) reports were adverse events. Eight of those reports were for injection site reactions. Unpublished data from the Vaccine Safety Datalink found no link between repeated Tdap doses within 12 months of prior Tdap and increased adverse events when compared with Td given within 12 months of prior Tdap in a retrospective cohort study of 13,599 non-pregnant adolescents and adults aged 11 to 64 years. Final recommendations will be published in the CDC's Morbidity and Mortality Weekly Report. Source
