{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T20:41:40Z","timestamp":1790628100411,"version":"4.1.0"},"reference-count":30,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2022,8,9]],"date-time":"2022-08-09T00:00:00Z","timestamp":1660003200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Commission\u2019s Joint Research Centre (JRC)"},{"name":"Department of Medical Biotechnologies of the University of Siena"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>PEGylated lipids are one of the four constituents of lipid nanoparticle mRNA COVID-19 vaccines. Therefore, various concerns have been raised on the generation of anti-PEG antibodies and their potential role in inducing hypersensitivity reactions following vaccination or in reducing vaccine efficacy due to anti-carrier immunity. Here, we assess the prevalence of anti-PEG antibodies, in a cohort of vaccinated individuals, and give an overview of their time evolution after repeated vaccine administrations. Results indicate that, in our cohort, the presence of PEG in the formulation did not influence the level of anti-Spike antibodies generated upon vaccination and was not related to any reported, serious adverse effects. The time-course analysis of anti-PEG IgG showed no significant booster effect after each dose, whereas for IgM a significant increase in antibody levels was detected after the first and third dose. Data suggest that the presence of PEG in the formulation does not affect safety or efficacy of lipid-nanoparticle-based COVID-19 vaccines.<\/jats:p>","DOI":"10.3390\/ijms23168838","type":"journal-article","created":{"date-parts":[[2022,8,10]],"date-time":"2022-08-10T02:42:53Z","timestamp":1660099373000},"page":"8838","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":90,"title":["Monitoring Anti-PEG Antibodies Level upon Repeated Lipid Nanoparticle-Based COVID-19 Vaccine Administration"],"prefix":"10.3390","volume":"23","author":[{"given":"Giuditta","family":"Guerrini","sequence":"first","affiliation":[{"name":"European Commission, Joint Research Centre (JRC), Ispra, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7150-9523","authenticated-orcid":false,"given":"Sabrina","family":"Gioria","sequence":"additional","affiliation":[{"name":"European Commission, Joint Research Centre (JRC), Ispra, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aisha V.","family":"Sauer","sequence":"additional","affiliation":[{"name":"European Commission, Joint Research Centre (JRC), Ispra, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3545-7433","authenticated-orcid":false,"given":"Simone","family":"Lucchesi","sequence":"additional","affiliation":[{"name":"Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2267-1337","authenticated-orcid":false,"given":"Francesca","family":"Montagnani","sequence":"additional","affiliation":[{"name":"Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy"},{"name":"Department of Medical Sciences, Infectious and Tropical Diseases Unit, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabiria","family":"Pastore","sequence":"additional","affiliation":[{"name":"Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4585-7783","authenticated-orcid":false,"given":"Annalisa","family":"Ciabattini","sequence":"additional","affiliation":[{"name":"Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Donata","family":"Medaglini","sequence":"additional","affiliation":[{"name":"Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luigi","family":"Calzolai","sequence":"additional","affiliation":[{"name":"European Commission, Joint Research Centre (JRC), Ispra, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"v","DOI":"10.1016\/j.coi.2016.07.001","article-title":"Editorial overview: Vaccines: Novel technologies for vaccine development","volume":"41","author":"Rappuoli","year":"2016","journal-title":"Curr. 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