{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,18]],"date-time":"2026-06-18T15:28:47Z","timestamp":1781796527051,"version":"3.54.5"},"reference-count":0,"publisher":"Journal of Infection in Developing Countries","issue":"01","license":[{"start":{"date-parts":[[2025,1,31]],"date-time":"2025-01-31T00:00:00Z","timestamp":1738281600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Infect Dev Ctries"],"abstract":"<jats:p>Introduction: Diphtheria is a serious infectious disease although being vaccine-preventable. 5-year follow-up study aimed to evaluate the persistence of IgG antibodies to diphtheria toxoid after Tetanus-diphtheria primary immunization for persons aged 6-25 years in Kon Tum, Viet Nam.\nMethodology: Blood samples were obtained from 128 healthy persons aged 6-25 years collected in 2021. Samples were tested for diphtheria toxoid antibodies by commercial Anti-Diphtheria Toxoid IgG Enzyme-Linked Immunosorbent Assay (ELISA).\nResults: One month after Td primary vaccination, 92.2% of participants were fully protected against diphtheria (&gt; 0.1 IU\/mL). GMCs increased from 0.04 to 0.91 IU\/mL at one month, which were maintained in nearly 90% of vaccinees at 5 years. Among children aged 6-10 years, 97.3% had full protection at 1 month after primary vaccination, maintained in 94.6% at 5 years. Among adolescents and adults, 81.0% to 98.5% had full protection at 1 month after vaccination, which were maintained from 72.7% to 96.7% at 5 years. Although, the antibodies slightly declined approximately 5 years post-vaccination, but remained several-fold higher than pre-vaccination.\nConclusions: Td vaccine provides long-lasting protective antibodies against diphtheria. These data may inform discussion of the need for Td booster vaccinations among high-risk persons.<\/jats:p>","DOI":"10.3855\/jidc.19390","type":"journal-article","created":{"date-parts":[[2025,2,19]],"date-time":"2025-02-19T18:38:06Z","timestamp":1739990286000},"page":"22-27","source":"Crossref","is-referenced-by-count":2,"title":["The evaluation of anti-diphtheria toxoid antibodies after 5 years with the primary Tetanus-Diphtheria vaccine in persons aged 6-25 years in Kon Tum, Vietnam: a follow-up study"],"prefix":"10.3855","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1231-6104","authenticated-orcid":false,"given":"Tuan Van","family":"Le","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Van Thi Tuyet","family":"Nguyen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-5413-9587","authenticated-orcid":false,"given":"Quan Hoang","family":"Nguyen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huong Le Thien","family":"Tran","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-7361-3969","authenticated-orcid":false,"given":"Son Dinh","family":"Tran","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chien Chinh","family":"Vien","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"2222","published-online":{"date-parts":[[2025,1,31]]},"container-title":["The Journal of Infection in Developing Countries"],"original-title":[],"link":[{"URL":"https:\/\/www.jidc.org\/index.php\/journal\/article\/download\/19390\/3565","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.jidc.org\/index.php\/journal\/article\/download\/19390\/3565","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,2,19]],"date-time":"2025-02-19T18:38:06Z","timestamp":1739990286000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.jidc.org\/index.php\/journal\/article\/view\/19390"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,1,31]]},"references-count":0,"journal-issue":{"issue":"01","published-online":{"date-parts":[[2025,1,31]]}},"URL":"https:\/\/doi.org\/10.3855\/jidc.19390","relation":{},"ISSN":["1972-2680"],"issn-type":[{"value":"1972-2680","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,1,31]]}}}