Male sex and age biases viral burden, viral shedding, and type 1 and 2 interferon responses during SARS-CoV-2 infection in ferrets.

SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) hospitalizations and deaths disportionally affect males and the elderly. Here we investigated the impact of male sex and age by infecting adult male, aged male, and adult female ferrets with SARS-CoV-2. Aged male ferrets had a decrease in temperature which was accompanied by prolonged viral replication with increased pathology in the upper respiratory tract after infection. Transcriptome analysis of the nasal turbinates and lungs indicated that female ferrets had significant increases in interferon response genes (OASL, MX1, ISG15, etc.) on day 2 post infection which was delayed in aged males. In addition, genes associated with taste and smell such as RTP1, CHGA, and CHGA1 at later time points were upregulated in males but not in females. These results provide insight into COVID-19 and suggests that older males may play a role in viral transmission due to decreased antiviral responses.