Tuesday, March 6, 2007 - 2:35 PM

Safety of Tdap for Mass Immunization of Health-Care Personnel (HCP)

Kristin H. Brown1, Elizabeth A. Talbot2, Kathryn B. Kirkland2, Andrew L. Baughman3, Katrina Kretsinger1, Scott Halperin4, Robert McLellan5, Manisha Patel1, and Karen R. Broder1. (1) National Center for Immunization and Respiratory Diseases/DBD/MVPD (proposed), Centers for Disease Control and Prevention, 1600 Clifton Road NE, MS C-25, Atlanta, GA, USA, (2) Dartmouth College, Lebanon, NH, (3) National Center for Immunization and Respiratory Diseases/DBD/Biostatistics Office, Centers for Disease Control and Prevention, Atlanta, USA, (4) Dalhousie University, Halifax, NS, Canada, (5) Dartmouth-Hitchcock Medical Center, Lebanon, NH

Learning Objectives for this Presentation:
By the end of the presentation participants will be able to
1. Understand Tdap recommendations for HCP.
2. Evaluate safety data on routine and non-routine Tdap use in mass immunization of HCP.

Tdap is recommended for non-pregnant HCP aged <65 years who received Td/TT ≥2 years earlier (routine HCP). A hospital offered Tdap to routine HCP and non-routine HCP who received Td/TT <2 years earlier (<2yr interval group), were aged ≥65 years, or were pregnant.

1. Describe Tdap safety in vaccinated HCP.
2. Compare adverse event (AE) rates in non-routine and routine HCP.

Vaccinee surveys collected time since Td/TT, age, and pregnancy status, and solicited moderate/severe local AE and subjective fever experiences during the 2 weeks after vaccination. Serious AEs (SAEs) were also assessed. AEs rates in non-routine HCP were compared with rates in routine HCP and were similar or lower if the difference in the rates (Δ) (non-routine routine) had an upper 95% confidence limit (CL) <10%.

Among 2,676 survey respondents, 400 received Td/TT <2 years earlier, 77 were aged ≥65 years, and 25 were pregnant. Overall, low rates of AEs were reported: pain 18%, redness 7%, swelling 11%, and fever 13%. Three SAEs were identified among 4,624 vaccinees. All AE rates in non-routine HCP were similar to or lower than (upper 95% CLΔ <10%) rates in routine HCP except the rate of redness in HCP ≥65 years (Δ=3, [ -8,13] ) and the rate of fever in pregnant HCP (Δ=1, [ -17,19] ).

Tdap was safe when used for mass immunization of HCP. AE rates in the <2yr interval group were similar to or lower than rates in routine HCP, suggesting acceptable safety in HCP vaccinated with Tdap <2 years after Td/TT. For older and pregnant HCP, interpretation of AE rate comparability is limited by small sample size.