An effective CTL peptide vaccine for Ebola Zaire Based on Survivors' CD8+ targeting of a particular nucleocapsid protein epitope with potential implications for COVID-19 vaccine design

Vaccine. 2020 Jun 9;38(28):4464-4475. doi: 10.1016/j.vaccine.2020.04.034. Epub 2020 Apr 28.


The 2013-2016 West Africa EBOV epidemic was the biggest EBOV outbreak to date. An analysis of virus-specific CD8+ T-cell immunity in 30 survivors showed that 26 of those individuals had a CD8+ response to at least one EBOV protein. The dominant response (25/26 subjects) was specific to the EBOV nucleocapsid protein (NP). It has been suggested that epitopes on the EBOV NP could form an important part of an effective T-cell vaccine for Ebola Zaire. We show that a 9-amino-acid peptide NP44-52 (YQVNNLEEI) located in a conserved region of EBOV NP provides protection against morbidity and mortality after mouse adapted EBOV challenge. A single vaccination in a C57BL/6 mouse using an adjuvanted microsphere peptide vaccine formulation containing NP44-52 is enough to confer immunity in mice. Our work suggests that a peptide vaccine based on CD8+ T-cell immunity in EBOV survivors is conceptually sound and feasible. Nucleocapsid proteins within SARS-CoV-2 contain multiple Class I epitopes with predicted HLA restrictions consistent with broad population coverage. A similar approach to a CTL vaccine design may be possible for that virus.

Keywords: COVID-19; CTL Vaccine; Controller; Ebola Zaire vaccine; Flow Focusing; SARS-CoV-2; YQVNNLEEI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • COVID-19
  • COVID-19 Vaccines
  • Coronavirus Infections / immunology
  • Coronavirus Infections / prevention & control
  • Disease Models, Animal
  • Drug Design*
  • Ebola Vaccines / chemistry
  • Ebola Vaccines / immunology*
  • Epitopes, T-Lymphocyte / chemistry
  • Epitopes, T-Lymphocyte / immunology*
  • Hemorrhagic Fever, Ebola / immunology
  • Hemorrhagic Fever, Ebola / prevention & control
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Nucleocapsid Proteins / chemistry
  • Nucleocapsid Proteins / immunology*
  • Pandemics / prevention & control
  • Pneumonia, Viral / immunology
  • Pneumonia, Viral / prevention & control
  • T-Lymphocytes, Cytotoxic / immunology*
  • Vaccines, Subunit / chemistry
  • Vaccines, Subunit / immunology*
  • Viral Vaccines* / chemistry
  • Viral Vaccines* / immunology


  • COVID-19 Vaccines
  • Ebola Vaccines
  • Epitopes, T-Lymphocyte
  • Nucleocapsid Proteins
  • Vaccines, Subunit
  • Viral Vaccines
  • nucleocapsid protein, Ebola virus