Frontiers in Immunology (Nov 2021)

The Bacterial Mucosal Immunotherapy MV130 Protects Against SARS-CoV-2 Infection and Improves COVID-19 Vaccines Immunogenicity

  • Carlos del Fresno,
  • Carlos del Fresno,
  • Juan García-Arriaza,
  • Sarai Martínez-Cano,
  • Sarai Martínez-Cano,
  • Ignacio Heras-Murillo,
  • Aitor Jarit-Cabanillas,
  • Joaquín Amores-Iniesta,
  • Paola Brandi,
  • Gillian Dunphy,
  • Carmen Suay-Corredera,
  • Maria Rosaria Pricolo,
  • Natalia Vicente,
  • Andrés López-Perrote,
  • Sofía Cabezudo,
  • Ana González-Corpas,
  • Oscar Llorca,
  • Jorge Alegre-Cebollada,
  • Urtzi Garaigorta,
  • Pablo Gastaminza,
  • Mariano Esteban,
  • David Sancho

DOI
https://doi.org/10.3389/fimmu.2021.748103
Journal volume & issue
Vol. 12

Abstract

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COVID-19-specific vaccines are efficient prophylactic weapons against SARS-CoV-2 virus. However, boosting innate responses may represent an innovative way to immediately fight future emerging viral infections or boost vaccines. MV130 is a mucosal immunotherapy, based on a mixture of whole heat-inactivated bacteria, that has shown clinical efficacy against recurrent viral respiratory infections. Herein, we show that the prophylactic intranasal administration of this immunotherapy confers heterologous protection against SARS-CoV-2 infection in susceptible K18-hACE2 mice. Furthermore, in C57BL/6 mice, prophylactic administration of MV130 improves the immunogenicity of two different COVID-19 vaccine formulations targeting the SARS-CoV-2 spike (S) protein, inoculated either intramuscularly or intranasally. Independently of the vaccine candidate and vaccination route used, intranasal prophylaxis with MV130 boosted S-specific responses, including CD8+-T cell activation and the production of S-specific mucosal IgA antibodies. Therefore, the bacterial mucosal immunotherapy MV130 protects against SARS-CoV-2 infection and improves COVID-19 vaccines immunogenicity.

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