ACIP: Tdap OK for decennial booster, tetanus prophylaxis, catch-up series
The CDC’s Advisory Committee on Immunization Practices voted unanimously today to recommend that either Td or Tdap may be used for the decennial Td booster, as tetanus prophylaxis for wound management in nonpregnant patients who previously received Tdap, and as additional doses of the catch-up immunization series for tetanus, diphtheria and pertussis in patients 7 years of age or older, including those who are pregnant.
Previously, only Td vaccine had been recommended in these situations, but the ACIP work group on pertussis vaccines said it reviewed published and unpublished data suggesting that clinicians were using Tdap in place of Td.
Pedro L. Moro , MD, MPH , an epidemiologist in CDC’s Immunization Safety Office, presented available data to the committee that examined the safety of closely scheduled Tdap doses in the setting of the catch-up immunization schedule.
“Limited data exist on the safety of the current vs. the proposed catch-up schedule for adolescents and adults,” Moro said at the meeting. “An approach to address this issue is to look at published and unpublished data on the safety of immunization regimens similar to the proposed schedule and administering closely spaced — and by closely spaced we mean less than 12 months apart — Tdap doses.”
In terms of published studies, Mauro cited two. The first study had three arms — three doses of Tdap; one dose of Tdap-IPV, followed by two doses of Td; or three doses of Td vaccine (acting as the control group). All 460 participants received vaccines at 0, 1 and 6 months. According to Mauro, the outcomes were immunogenicity and reactogenicity, with no statistically significant differences in local or general symptoms between groups.
A cohort study examined Tdap reactogenicity among 374 pregnant and 225 nonpregnant women, with a special focus on eight women who had more than one Tdap dose within 12 months. Mauro said there were no adverse events of concern; however, it was a small group of women that was studied.
The group also examined unpublished data from the Vaccine Adverse Reporting System on people in the U.S. who received more than one dose of Tdap, and through an unpublished retrospective cohort study evaluating 13,599 nonpregnant adolescents and adults who received repeated Tdap doses. Both showed no association between repeated Tdap doses and an increase in any adverse events compared with Td within 12 months of prior Tdap.
Mauro said that although the data were limited, the review of published and unpublished safety data was reassuring. The committee voted unanimously in favor of all the changes. – by Caitlyn Stulpin
Disclosure: Moro reports no relevant financial disclosures.