Diagnostics (Jul 2022)

An RBD-Based Diagnostic Method Useful for the Surveillance of Protective Immunity against SARS-CoV-2 in the Population

  • Dolores Adriana Ayón-Núñez,
  • Jacquelynne Cervantes-Torres,
  • Carlos Cabello-Gutiérrez,
  • Sergio Rosales-Mendoza,
  • Diana Rios-Valencia,
  • Leonor Huerta,
  • Raúl J. Bobes,
  • Julio César Carrero,
  • René Segura-Velázquez,
  • Nora Alma Fierro,
  • Marisela Hernández,
  • Joaquín Zúñiga-Ramos,
  • Gerardo Gamba,
  • Graciela Cárdenas,
  • Emmanuel Frías-Jiménez,
  • Luis Alonso Herrera,
  • Gladis Fragoso,
  • Edda Sciutto,
  • Francisco Suárez-Güemes,
  • Juan Pedro Laclette

DOI
https://doi.org/10.3390/diagnostics12071629
Journal volume & issue
Vol. 12, no. 7
p. 1629

Abstract

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After more than two years, the COVID-19 pandemic is still ongoing and evolving all over the world; human herd immunity against SARS-CoV-2 increases either by infection or by unprecedented mass vaccination. A substantial change in population immunity is expected to contribute to the control of transmission. It is essential to monitor the extension and duration of the population’s immunity to support the decisions of health authorities in each region and country, directed to chart the progressive return to normality. For this purpose, the availability of simple and cheap methods to monitor the levels of relevant antibodies in the population is a widespread necessity. Here, we describe the development of an RBD-based ELISA for the detection of specific antibodies in large numbers of samples. The recombinant expression of an RBD-poly-His fragment was carried out using either bacterial or eukaryotic cells in in vitro culture. After affinity chromatography purification, the performance of both recombinant products was compared by ELISA in similar trials. Our results showed that eukaryotic RBD increased the sensitivity of the assay. Interestingly, our results also support a correlation of the eukaryotic RBD-based ELISA with other assays aimed to test for neutralizing antibodies, which suggests that it provides an indication of protective immunity against SARS-CoV-2.

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