Immunogenicity of an adenoviral-based Middle East Respiratory Syndrome coronavirus vaccine in BALB/c mice

Vaccine. 2014 Oct 14;32(45):5975-82. doi: 10.1016/j.vaccine.2014.08.058. Epub 2014 Sep 3.

Abstract

A new type of coronavirus has been identified as the causative agent underlying Middle East Respiratory Syndrome (MERS). The MERS coronavirus (MERS-CoV) has spread in the Middle East, but cases originating in the Middle East have also occurred in the European Union and the USA. Eight hundred and thirty-seven cases of MERS-CoV infection have been confirmed to date, including 291 deaths. MERS-CoV has infected dromedary camel populations in the Middle East at high rates, representing an immediate source of human infection. The MERS-CoV spike (S) protein, a characteristic structural component of the viral envelope, is considered as a key target of vaccines against coronavirus infection. In an initial attempt to develop a MERS-CoV vaccine to ultimately target dromedary camels, we constructed two recombinant adenoviral vectors encoding the full-length MERS-CoV S protein (Ad5.MERS-S) and the S1 extracellular domain of S protein (Ad5.MERS-S1). BALB/c mice were immunized with both candidate vaccines intramuscularly and boosted three weeks later intranasally. All the vaccinated animals had antibody responses against spike protein, which neutralized MERS-CoV in vitro. These results show that an adenoviral-based vaccine can induce MERS-CoV-specific immune responses in mice and hold promise for the development of a preventive vaccine that targets the animal reservoir, which might be an effective measure to eliminate transmission of MERS-CoV to humans.

Keywords: Adenoviral vaccines; Codon-optimized; MERS-CoV S.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae*
  • Animals
  • Antibodies, Neutralizing / blood
  • Antibodies, Viral / blood
  • Antibody Formation
  • Camelus
  • Coronavirus Infections / prevention & control*
  • HEK293 Cells
  • Humans
  • Immunoglobulin G / blood
  • Mice, Inbred BALB C
  • Middle East Respiratory Syndrome Coronavirus*
  • Neutralization Tests
  • Spike Glycoprotein, Coronavirus / immunology
  • Viral Vaccines / immunology*

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Immunoglobulin G
  • Spike Glycoprotein, Coronavirus
  • Viral Vaccines