{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T15:06:55Z","timestamp":1772118415488,"version":"3.50.1"},"reference-count":48,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2021,11,10]],"date-time":"2021-11-10T00:00:00Z","timestamp":1636502400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Eur J Immunol"],"published-print":{"date-parts":[[2022,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>During the COVID\u201019 pandemic, Portugal has experienced three distinct SARS\u2010CoV\u20102 infection waves. We previously documented the prevalence of SARS\u2010CoV\u20102 immunity, measured by specific antibodies, in September 2020, 6 months after the initial moderate wave. Here, we show the seroprevalence changes 6 months later, up to the second week of March 2021, shortly following the third wave, which was one of the most severe in the world, and 2 months following the start of the vaccination campaign. A longitudinal epidemiological study was conducted, with a stratified quota sample of the Portuguese population. Serological testing was performed, including ELISA determination of antibody class and titers. The proportion of seropositives, which was 2.2% in September 2020, rose sharply to 17.3% (95% CI: 15.8\u201318.8%) in March 2021. Importantly, circulating IgG and IgA antibody levels were very stable 6 months after the initial determination and up to a year after initial infection, indicating long\u2010lasting infection immunity against SARS\u2010CoV\u20102. Moreover, vaccinated people had higher IgG levels from 3\u00a0weeks post\u2010vaccination when compared with previously infected people at the same time post\u2010infection.<\/jats:p>","DOI":"10.1002\/eji.202149619","type":"journal-article","created":{"date-parts":[[2021,10,25]],"date-time":"2021-10-25T14:12:42Z","timestamp":1635171162000},"page":"149-160","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Longitudinal SARS\u2010CoV\u20102 seroprevalence in Portugal and antibody maintenance 12 months after infection"],"prefix":"10.1002","volume":"52","author":[{"given":"Lu\u00edsa","family":"Canto e Castro","sequence":"first","affiliation":[{"name":"Faculdade de Ci\u00eancias, Centro de Estat\u00edstica e Aplica\u00e7\u00f5es e Funda\u00e7\u00e3o Francisco Manuel dos Santos Universidade de Lisboa  Lisbon Portugal"}]},{"given":"Andreia","family":"Gomes","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"Marta","family":"Serrano","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"Ana Helena Guia","family":"Pereira","sequence":"additional","affiliation":[{"name":"Centro de Medicina Laboratorial Germano de Sousa  Lisbon Portugal"}]},{"given":"Rita","family":"Ribeiro","sequence":"additional","affiliation":[{"name":"Centro de Medicina Laboratorial Germano de Sousa  Lisbon Portugal"}]},{"given":"Patr\u00edcia","family":"Napole\u00e3o","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"In\u00eas","family":"Domingues","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"Cl\u00e1udia","family":"Silva","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"J\u00falia","family":"Fanczal","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"\u00c2ngela","family":"Afonso","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"Andreia","family":"Lopes","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"Ionela","family":"Toader","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"Maria Jos\u00e9 Rego","family":"de 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de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"}]},{"given":"Ruy M.","family":"Ribeiro","sequence":"additional","affiliation":[{"name":"Instituto de Medicina Molecular Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"},{"name":"Laborat\u00f3rio de Biomatem\u00e1tica, Instituto de Sa\u00fade Ambiental Faculdade de Medicina Universidade de Lisboa  Lisbon Portugal"},{"name":"Theoretical Biology and Biophysics Los Alamos National Laboratory  New Mexico 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