Morozov Igor, Gaudreault Natasha N, Trujillo Jessie D, Indran Sabarish V, Cool Konner, Kwon Taeyong, Meekins David A, Balaraman Velmurugan, Artiaga Bianca Libanori, Madden Daniel W, McDowell Chester, Njaa Bradley, Retallick Jamie, Hainer Nicole, Millership Jason, Wilson William C, Tkalcevic George, Vander Horst Hanne, Burakova Yulia, King Vickie, Hutchinson Kendra, Hardham John M, Schwahn Denise J, Kumar Mahesh, Richt Juergen A
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA.
Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS 66506, USA.
Vaccines (Basel). 2023 Dec 8;11(12):1831. doi: 10.3390/vaccines11121831.
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.
本研究的目的是评估一种重组亚单位SARS-CoV-2动物疫苗对猫抵抗强毒株SARS-CoV-2攻击的安全性和有效性。两组猫分别用两剂重组SARS-CoV-2刺突蛋白疫苗或安慰剂进行免疫，间隔三周给药。第二次接种疫苗七周后，两组猫同时通过鼻内和口服途径接受SARS-CoV-2攻击。在感染后14天对动物进行临床症状和病毒脱落监测，然后实施安乐死并评估宏观和微观病变。重组SARS-CoV-2刺突蛋白亚单位疫苗在接种后诱导了强烈的血清学反应，并在攻击后显著提高了中和抗体反应。与 mock 疫苗接种对照组相比，接种疫苗的猫在鼻腔和口腔病毒脱落方面存在显著差异，病毒载量（使用RT-qPCR检测）显著降低。与对照组相比，接种疫苗的猫在鼻腔、口腔和直肠的病毒脱落持续时间也显著缩短。两组之间的组织病理学病变评分没有差异。我们的研究结果支持基于重组刺突蛋白的SARS-CoV-2疫苗的安全性和有效性，该疫苗诱导了高水平的中和抗体并减少了鼻腔、口腔和直肠的病毒脱落，表明这种疫苗作为家猫的COVID-19疫苗将是有效的。
