Dados do Trabalho

Título

Evaluation of SARS-CoV-2 variants in a Syrian Hamster experimental model of SARS-CoV-2 disease

Introdução

SARS-CoV-2 is responsible for more than 37 million severe human cases and 700000 deaths in Brazil. SARS-CoV-2 variants were characterized by variations in the S region of SARS-CoV-2, differential ability to spread in the environment and human transmission which raised discussions about the vaccine efficacy against new emergent variants. Golden Syrian Hamsters (Mesocricetus auratus) have high homology with the human ACE2 and clinical presentation similar with COVID-19 in humans.

Objetivo (s)

Evaluate the clinical aspects of different SARS-CoV-2 variants in a Syrian hamster experimental model of SARS-CoV-2 disease.

Material e Métodos

Syrian Hamsters were inoculated via intranasal with the SARS-CoV-2 variants (Alpha, B1.1.28, B1.1.33, Delta and Ômicron) and were euthanized in days 3, 5, 10 and 15 post infection. All animals were evaluated by the occurrence of SARS-CoV-2 clinical signs and mortality. Blood samples were collected and the neutralizing antibody titers were assessed. Oropharyngeal swab, lung, brain, liver, intestine and faeces were collected to evaluate the viral load by RT-PCR.

Resultados e Conclusão

All animals survived and severe weight loss was observed after 4 dpi only in animals infected with B1.1.28 and B1.1.33. All groups, except the Ômicron group, showed high viral load until 15 dpi in oropharyngeal swab and lung. Brain, liver and intestine showed low viral load. Oropharyngeal swab of animals of Ômicron group showed lower viral load when compared to Alpha. Lung of animals from Delta and Ômicron groups showed lower viral load when compared to Alpha. Only animals infected with Delta presented SARS-CoV-2 viral load after 5 dpi when the intestine was investigated. Only one animal infected with B1.1.33 showed viral load in brain after 5 dpi. Only the group infected with B1.1.28 not showed viral load in faeces. At last, the SARS-CoV-2 neutralization title begin to show in Alpha variant group at 3 dpi (21.18%), in groups B1.1.28 and Delta at 5 dpi (26.19% and 54.81% respectively) and in B1.1.33 and Ômicron group SARS-CoV-2 neutralization title begin at 10 dpi (89.50% and 60.86% respectively). Therefore, the most severe infection were observed in animals infected with Alpha and Beta (B1.1.28 and B1.1.33) and there are different infection profiles between the variants in a Syrian Hamster model of SARS-CoV-2 infection which demonstrate the difference between the variants evolution through the SARS-CoV-2 pandemic.

Palavras-chave

COVID-19. SARS-CoV-2 variants. Golden Syrian Hamster.

Agradecimentos

Faperj e CNPq