{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T10:32:09Z","timestamp":1779100329040,"version":"3.51.4"},"reference-count":26,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,4,9]],"date-time":"2025-04-09T00:00:00Z","timestamp":1744156800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Italian Ministry of Health Ricerca Corrente Linea 2","award":["871029"],"award-info":[{"award-number":["871029"]}]},{"name":"European Commission-Horizon 2020","award":["871029"],"award-info":[{"award-number":["871029"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The new Nuvaxovid protein-based and Pfizer-BioNTech mRNA-based vaccines targeting Omicron XBB.1.5 were available during the 2023\u20132024 autumn\/winter vaccination campaign for frail individuals, including people with HIV (PWH). We assessed the immune response in 51 PWH on stable ART who received a booster with either the Nuvaxovid protein-based (n = 25) or Pfizer-BioNTech mRNA-based XBB.1.5 vaccine (n = 26). The median age was 57 years (IQR 51\u201365), the median count of CD4 at T0 was 652\/mmc (503\u2013935), and CD4 nadir was 226\/mmc (95\u2013340). Samples were collected before (T0) and one month after (T1) the booster. We measured neutralizing antibodies (nAbs) titers against D614G, XBB.1.6, and JN.1 variants and T-cell IFN-\u03b3 levels produced upon specific stimulation. Regardless of the vaccine used, we observed a marked increase in nAbs titers from T0 to T1 against all the subvariants, but no evidence for a change in IFN-\u03b3 release. After controlling for confounders, there was no evidence for a difference in the T0-T1 change in nAbs titers against XBB.1.16 and JN.1 by the type of vaccine, while Nuvaxovid determined a smaller increase in D614G nAbs (p = 0.008). The XBB.1.5 protein-based vaccine\u2019s immunogenicity as a fifth or later booster was comparable to the Pfizer-BioNTech mRNA vaccine, particularly against recent Omicron variants.<\/jats:p>","DOI":"10.3390\/ijms26083521","type":"journal-article","created":{"date-parts":[[2025,4,9]],"date-time":"2025-04-09T07:49:02Z","timestamp":1744184942000},"page":"3521","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Immune Response Against Recent Omicron Sub-Lineages in Persons with HIV Receiving a Protein-Based or mRNA XBB.1.5 SARS-CoV-2 Booster Vaccine"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6944-0686","authenticated-orcid":false,"given":"Alessandra","family":"Vergori","sequence":"first","affiliation":[{"name":"Viral Immunodeficiency Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2948-4243","authenticated-orcid":false,"given":"Giulia","family":"Matusali","sequence":"additional","affiliation":[{"name":"Virology Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2659-0868","authenticated-orcid":false,"given":"Eleonora","family":"Cimini","sequence":"additional","affiliation":[{"name":"Laboratory of Cellular Immunology and Pharmacology, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6339-919X","authenticated-orcid":false,"given":"Alessandro","family":"Cozzi Lepri","sequence":"additional","affiliation":[{"name":"Institute of Global Health, University College London, CREME Center, London KT1 2EE, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0240-7504","authenticated-orcid":false,"given":"Valentina","family":"Mazzotta","sequence":"additional","affiliation":[{"name":"Viral Immunodeficiency Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7698-1103","authenticated-orcid":false,"given":"Davide","family":"Mariotti","sequence":"additional","affiliation":[{"name":"Virology Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0640-8667","authenticated-orcid":false,"given":"Francesca","family":"Colavita","sequence":"additional","affiliation":[{"name":"Virology Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Simona","family":"Gili","sequence":"additional","affiliation":[{"name":"Laboratory of Cellular Immunology and Pharmacology, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Flavia","family":"Cristofanelli","sequence":"additional","affiliation":[{"name":"Laboratory of Cellular Immunology and Pharmacology, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marisa","family":"Fusto","sequence":"additional","affiliation":[{"name":"Viral Immunodeficiency Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6351-2623","authenticated-orcid":false,"given":"Roberta","family":"Gagliardini","sequence":"additional","affiliation":[{"name":"Viral Immunodeficiency Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-8361-9605","authenticated-orcid":false,"given":"Jessica","family":"Paulicelli","sequence":"additional","affiliation":[{"name":"Viral Immunodeficiency Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Federico","family":"Cecilia","sequence":"additional","affiliation":[{"name":"Viral Immunodeficiency Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"},{"name":"Infectious Disease Unit, Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8182-5896","authenticated-orcid":false,"given":"Enrico","family":"Girardi","sequence":"additional","affiliation":[{"name":"Scientific Direction, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7489-5271","authenticated-orcid":false,"given":"Fabrizio","family":"Maggi","sequence":"additional","affiliation":[{"name":"Virology Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2121-4684","authenticated-orcid":false,"given":"Andrea","family":"Antinori","sequence":"additional","affiliation":[{"name":"Viral Immunodeficiency Unit, National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e58","DOI":"10.1017\/S0950268823000420","article-title":"Comparative transmission of SARS-CoV-2 Omicron (B.1.1.529) and Delta (B.1.617.2) variants and the impact of vaccination: National cohort study, England","volume":"151","author":"Allen","year":"2023","journal-title":"Epidemiol. Infect."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2200125","DOI":"10.2807\/1560-7917.ES.2022.27.45.2200125","article-title":"Tracking the progressive spread of the SARS-CoV-2 Omicron variant in Italy, December 2021 to January 2022","volume":"27","author":"Stefanelli","year":"2022","journal-title":"Eurosurveillance"},{"key":"ref_3","unstructured":"(2025, March 27). 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