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Volume 27, Number 11—November 2021

Prevalence of SARS-CoV-2 Antibodies after First 6 Months of COVID-19 Pandemic, Portugal

Luísa Canto e Castro, Ana Helena Guia Pereira, Rita Ribeiro, Catarina Alves, Luís Veloso, Vera Vicente, Dalila Alves, Inês Domingues, Cláudia Silva, Andreia Gomes, Marta Serrano, Ângela Afonso, Marc Veldhoen, Maria José Rego de Sousa, José Germano Rego de Sousa, Germano de Sousa, Maria M. Mota, Bruno Silva-Santos1, and Ruy M. Ribeiro1Comments to Author 
Author affiliations: Fundação Francisco Manuel dos Santos, Lisbon, Portugal (L. Canto e Castro); Universidade de Lisboa, Lisbon (L. Canto e Castro, I. Domingues, C. Silva, A. Gomes, M. Serrano, Â. Afonso, M. Veldhoen, M.M. Mota, B. Silva-Santos, R.M. Ribeiro); Centro de Medicina Laboratorial Germano de Sousa, Lisbon (A.H.G. Pereira, R. Ribeiro, M.J. Rego de Sousa, J.G. Rego de Sousa, G. de Sousa); CTI Clinical Trial and Consulting Services, Portugal (C. Alves, L. Veloso, V. Vicente, D. Alves); Los Alamos National Laboratory, Los Alamos, New Mexico, USA (R.M. Ribeiro)

Main Article

Table 1

Prevalence of antibodies against severe acute respiratory syndrome coronavirus 2, by person age, adjusted for sensitivity and specificity, Portugal, September 8‒October 14, 2020

Population density Seroprevalence, % (95% CI), by age, y
<18, n = 2,108 18–54, n = 6,495 >55, n = 4,795 Overall, n = 13,398
Low, n = 2,298 0.6 (0.2‒2.8) 1.5 (0.9‒2.6) 1.7 (1.0‒2.9) 1.4 (1.1‒2.2)
Medium, n = 5,006 1.4 (0.8‒2.7) 1.7 (1.3‒2.4) 1.7 (1.2‒2.5) 1.6 (1.4‒2.1)
High, n = 6,094 3.5 (2.5‒5.0) 3.1 (2.6‒3.9) 2.2 (1.7‒3.1) 2.9 (2.5‒3.4)
Overall 2.4 (1.9‒3.3) 2.3 (2.0‒2.8) 1.9 (1.6‒2.4) 2.2 (2.0‒2.5)

Main Article

1These authors were co-senior authors.

Page created: August 10, 2021
Page updated: October 19, 2021
Page reviewed: October 19, 2021
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