BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Longitudinal SARS‐CoV‐2 seroprevalence in Portugal and antibody maintenance 12 months after infection

Participants in the publication
Luísa Canto e Castro (Author)
Dep. Estatística e Investigação Operacional
CEAUL
Andreia Gomes (Author)
Marta Serrano (Author)
Ana Helena Guia Pereira (Author)
Rita Ribeiro (Author)
Patrícia Napoleão (Author)
Inês Domingues (Author)
Cláudia Silva (Author)
Júlia Fanczal (Author)
à ngela Afonso (Author)
Andreia Lopes (Author)
Ionela Toader (Author)
Maria José Rego Sousa (Author)
José Germano Rego Sousa (Author)
Germano Sousa (Author)
Maria M. Mota (Author)
Bruno Silva-Santos (Author)
Marc Veldhoen (Author)
Ruy M. Ribeiro (Author)

Summary
During the COVID-19 pandemic, Portugal has experienced three distinct SARS-CoV-2 infection waves. We previously documented the prevalence of SARS-CoV-2 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: 15.8–18.8%) 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-lasting infection immunity against SARS-CoV-2. Moreover, vaccinated people had higher IgG levels from 3 weeks post-vaccination when compared with previously infected people at the same time post-infection.


Where published
European Journal of Immunology

Publication Identifiers
ISSN - 0014-2980

Publisher
Wiley



Document Identifiers
DOI - https://doi.org/10.1002/eji.202149619
URL - http://dx.doi.org/10.1002/eji.202149619

Rankings
SCIMAGO Q1 (2020) - 2.272 - Immunology