Ad26 vaccine protects against SARS-CoV-2 severe clinical disease in hamsters

Nat Med. 2020 Nov;26(11):1694-1700. doi: 10.1038/s41591-020-1070-6. Epub 2020 Sep 3.


Coronavirus disease 2019 (COVID-19) in humans is often a clinically mild illness, but some individuals develop severe pneumonia, respiratory failure and death1-4. Studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in hamsters5-7 and nonhuman primates8-10 have generally reported mild clinical disease, and preclinical SARS-CoV-2 vaccine studies have demonstrated reduction of viral replication in the upper and lower respiratory tracts in nonhuman primates11-13. Here we show that high-dose intranasal SARS-CoV-2 infection in hamsters results in severe clinical disease, including high levels of virus replication in tissues, extensive pneumonia, weight loss and mortality in a subset of animals. A single immunization with an adenovirus serotype 26 vector-based vaccine expressing a stabilized SARS-CoV-2 spike protein elicited binding and neutralizing antibody responses and protected against SARS-CoV-2-induced weight loss, pneumonia and mortality. These data demonstrate vaccine protection against SARS-CoV-2 clinical disease. This model should prove useful for preclinical studies of SARS-CoV-2 vaccines, therapeutics and pathogenesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenoviridae / genetics*
  • Adenoviridae / immunology
  • Animals
  • Antibodies, Neutralizing / genetics
  • Antibodies, Neutralizing / therapeutic use
  • COVID-19 / mortality
  • COVID-19 / pathology
  • COVID-19 / prevention & control*
  • COVID-19 / virology
  • COVID-19 Vaccines / genetics
  • COVID-19 Vaccines / therapeutic use*
  • Cricetinae
  • Disease Models, Animal
  • Female
  • Genetic Vectors
  • Humans
  • Male
  • Mesocricetus
  • SARS-CoV-2 / genetics
  • SARS-CoV-2 / immunology*
  • Severity of Illness Index
  • Spike Glycoprotein, Coronavirus / genetics*
  • Spike Glycoprotein, Coronavirus / immunology*
  • Vaccines, Synthetic / genetics
  • Vaccines, Synthetic / therapeutic use
  • Viral Load


  • Antibodies, Neutralizing
  • COVID-19 Vaccines
  • Spike Glycoprotein, Coronavirus
  • Vaccines, Synthetic
  • spike protein, SARS-CoV-2