{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,25]],"date-time":"2026-07-25T05:00:43Z","timestamp":1784955643015,"version":"3.55.0"},"reference-count":32,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T00:00:00Z","timestamp":1784246400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: Vaccine hesitancy (VH) is a complex global public health threat requiring validated tools for its assessment globally. This study aimed to evaluate an extended adult Vaccine Hesitancy Scale (aVHS) among Greek-speaking adults. Methods: This study evaluated a newly developed extended version of a widely used aVHS, incorporating five additional items on long-term safety, risk\u2013benefit evaluation, vaccine-related harm, scientific credibility, and perceived alternatives, on a cross-sectional sample of 491 adults in Greece and Cyprus. Cross-cultural adaptation of the extended aVHS involved translation, back-translation, and pilot testing. Structural validity was assessed using parallel analysis, exploratory factor analysis (EFA), and reliability using Cronbach\u2019s \u03b1 and McDonald\u2019s \u03c9. Criterion validity was assessed against focus-group classification using ROC analysis in 68 participants. Results: A one-factor EFA solution appeared the most parsimonious, showing strong loadings for the original and extended aVHS (0.67\u20130.86 and 0.65\u20130.87), with similar explained variance (60.31% and 60.06%). The one-factor solution was confirmed by parallel analysis for both scales. Internal consistency was excellent, and slightly higher for the extended than the original aVHS (\u03b1 = 0.95; \u03c9 = 0.95 vs. \u03b1 = 0.92; \u03c9 = 0.93). The five newly added items performed strongly, with item\u2013rest correlations of 0.69\u20130.85 and loadings of 0.72\u20130.87. Criterion validity was excellent, with a slightly higher AUC (0.991 vs. 0.981) and numerically higher classification performance for the extended than the original aVHS. Conclusions: The extended aVHS is a psychometrically coherent tool that improves the performance of the original scale among Greek-speaking individuals. This scale may enhance VH surveillance, aiding targeted vaccination communication strategies.<\/jats:p>","DOI":"10.3390\/vaccines14070628","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T07:54:13Z","timestamp":1784534053000},"page":"628","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Development and Validation of an Extended Adult Vaccine Hesitancy Scale in Greek-Speaking Populations"],"prefix":"10.3390","volume":"14","author":[{"given":"Andria","family":"Hadjikou","sequence":"first","affiliation":[{"name":"Department of Health Sciences, School of Life and Health Sciences, European University Cyprus, 6 Diogenis Street, 2404 Engomi, Cyprus"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Irene","family":"Heraclidou","sequence":"additional","affiliation":[{"name":"Department of Psychology, Faculty of Social Sciences and Education, University of Cyprus, 1678 Nicosia, Cyprus"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1304-3275","authenticated-orcid":false,"given":"Alexandros","family":"Heraclides","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, School of Life and Health Sciences, European University Cyprus, 6 Diogenis Street, 2404 Engomi, Cyprus"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"140","DOI":"10.2471\/BLT.07.040089","article-title":"Vaccination greatly reduces disease, disability, death and inequity worldwide","volume":"86","author":"Andre","year":"2008","journal-title":"Bull. 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