Adjuvanting a viral vectored vaccine against pre-erythrocytic malaria

Sci Rep. 2017 Aug 4;7(1):7284. doi: 10.1038/s41598-017-07246-0.

Abstract

The majority of routinely given vaccines require two or three immunisations for full protective efficacy. Single dose vaccination has long been considered a key solution to improving the global immunisation coverage. Recent infectious disease outbreaks have further highlighted the need for vaccines that can achieve full efficacy after a single administration. Viral vectors are a potent immunisation platform, benefiting from intrinsic immuno-stimulatory features while retaining excellent safety profile through the use of non-replicating viruses. We investigated the scope for enhancing the protective efficacy of a single dose adenovirus-vectored malaria vaccine in a mouse model of malaria by co-administering it with vaccine adjuvants. Out of 11 adjuvants, only two, Abisco®-100 and CoVaccineHTTM, enhanced vaccine efficacy and sterile protection following malaria challenge. The CoVaccineHTTM adjuvanted vaccine induced significantly higher proportion of antigen specific central memory CD8+ cells, and both adjuvants resulted in increased proportion of CD8+ T cells expressing the CD107a degranulation marker in the absence of IFNγ, TNFα and IL2 production. Our results show that the efficacy of vaccines designed to induce protective T cell responses can be positively modulated with chemical adjuvants and open the possibility of achieving full protection with a single dose immunisation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic
  • Animals
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism
  • Cytokines / metabolism
  • Disease Models, Animal
  • Epitopes, T-Lymphocyte / immunology
  • Female
  • Genetic Vectors* / administration & dosage
  • Genetic Vectors* / genetics
  • Genetic Vectors* / immunology
  • Immunization
  • Immunologic Memory
  • Life Cycle Stages* / immunology
  • Malaria / parasitology*
  • Malaria / prevention & control*
  • Malaria Vaccines / administration & dosage
  • Malaria Vaccines / genetics
  • Malaria Vaccines / immunology*
  • Mice
  • Plasmodium / genetics
  • Plasmodium / growth & development
  • Plasmodium / immunology*
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocyte Subsets / metabolism

Substances

  • Adjuvants, Immunologic
  • Cytokines
  • Epitopes, T-Lymphocyte
  • Malaria Vaccines