Preliminary Study on the Efficacy of a Recombinant, Subunit SARS-CoV-2 Animal Vaccine against Virulent SARS-CoV-2 Challenge in Cats
Igor Morozov,
Natasha N. Gaudreault,
Jessie D. Trujillo,
Sabarish V. Indran,
Konner Cool,
Taeyong Kwon,
David A. Meekins,
Velmurugan Balaraman,
Bianca Libanori Artiaga,
Daniel W. Madden,
Chester McDowell,
Bradley Njaa,
Jamie Retallick,
Nicole Hainer,
Jason Millership,
William C. Wilson,
George Tkalcevic,
Hanne Vander Horst,
Yulia Burakova,
Vickie King,
Kendra Hutchinson,
John M. Hardham,
Denise J. Schwahn,
Mahesh Kumar,
Juergen A. Richt
Affiliations
Igor Morozov
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Natasha N. Gaudreault
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Jessie D. Trujillo
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Sabarish V. Indran
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Konner Cool
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Taeyong Kwon
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
David A. Meekins
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Velmurugan Balaraman
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Bianca Libanori Artiaga
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Daniel W. Madden
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Chester McDowell
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
Bradley Njaa
Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS 66506, USA
Jamie Retallick
Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS 66506, USA
Nicole Hainer
Zoetis, Kalamazoo, MI 49007, USA
Jason Millership
Zoetis, Kalamazoo, MI 49007, USA
William C. Wilson
Foreign Arthropod-Borne Animal Disease Research Unit, National Bio and Agro-Defense Facility, United States Department of Agriculture, Manhattan, KS 66506, USA
George Tkalcevic
Zoetis, Kalamazoo, MI 49007, USA
Hanne Vander Horst
Zoetis, Kalamazoo, MI 49007, USA
Yulia Burakova
Zoetis, Kalamazoo, MI 49007, USA
Vickie King
Zoetis, Kalamazoo, MI 49007, USA
Kendra Hutchinson
Zoetis, Kalamazoo, MI 49007, USA
John M. Hardham
Zoetis, Kalamazoo, MI 49007, USA
Denise J. Schwahn
Zoetis, Kalamazoo, MI 49007, USA
Mahesh Kumar
Zoetis, Kalamazoo, MI 49007, USA
Juergen A. Richt
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
The objective of this work was to evaluate the safety and efficacy of a recombinant, subunit SARS-CoV-2 animal vaccine in cats against virulent SARS-CoV-2 challenge. Two groups of cats were immunized with two doses of either a recombinant SARS-CoV-2 spike protein vaccine or a placebo, administered three weeks apart. Seven weeks after the second vaccination, both groups of cats were challenged with SARS-CoV-2 via the intranasal and oral routes simultaneously. Animals were monitored for 14 days post-infection for clinical signs and viral shedding before being humanely euthanized and evaluated for macroscopic and microscopic lesions. The recombinant SARS-CoV-2 spike protein subunit vaccine induced strong serologic responses post-vaccination and significantly increased neutralizing antibody responses post-challenge. A significant difference in nasal and oral viral shedding, with significantly reduced virus load (detected using RT-qPCR) was observed in vaccinates compared to mock-vaccinated controls. Duration of nasal, oral, and rectal viral shedding was also significantly reduced in vaccinates compared to controls. No differences in histopathological lesion scores were noted between the two groups. Our findings support the safety and efficacy of the recombinant spike protein-based SARS-CoV-2 vaccine which induced high levels of neutralizing antibodies and reduced nasal, oral, and rectal viral shedding, indicating that this vaccine will be efficacious as a COVID-19 vaccine for domestic cats.