Surasak WiboonchutikulWeerawat ManosuthiChariya SangsajjaVaraporn ThientongSirirat LikanonsakulSomkid SrisophaPatamavadee TermvisesJitlada RujitipSuda LoiusirirotchanakulPilaipan PuthavathanaThailand Ministry of Public HealthMahidol University2018-11-092018-11-092014-01-01American Journal of Infection Control. Vol.42, No.7 (2014)15273296019665532-s2.0-84903313070https://repository.li.mahidol.ac.th/handle/123456789/34698A prospective study to evaluate immune status against diphtheria and immunologic response after tetanus-diphtheria (Td) booster vaccination was conducted in 250 Thai health care workers (HCWs). A protective antibody was found in 89.2% of the HCWs (95% confidence interval [CI], 83.3%-91.5%) before receipt of the Td booster vaccination, compared with 97.2% (95% CI, 95.1%-99.3%) after receipt of the first dose of booster (P <.001). The mean antibody level against diphtheria increased from 0.39 IU/mL (95% CI, 0.35-0.44 IU/mL) before the Td booster vaccination to 1.20 IU/mL (95% CI, 1.12-1.29 IU/mL) after the vaccination (P <.001). Td booster vaccination should be considered for Thai HCWs to maintain immunity against diphtheria, which still circulates in Thailand. © 2014 Published by Elsevier Inc.Mahidol UniversityMedicineArticleSCOPUS10.1016/j.ajic.2014.03.005