Long-term asymptomatic SARS-CoV-2 infection associated with deficiency on multiple immune cells.

The immune responses and the function of immune cells among asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection cases, especially in immuno-compromised individuals, remain largely unknown. Here we present a case of asymptomatic SARS-CoV-2 infection that lasted for at least 67 days. The patient has administrated Thymalfasin as 1.6 mg per dose every other day from Day 45 to 70, plus 200 mg per dose Arbidol antiviral therapy three doses per day from Day 48 to 57. Throughout the infection, no anti-SARS-CoV-2 specific IgM or IgG antibodies were detected. Instead, the patient showed either a low percentage or an absolute number of non-classical monocytes, dendritic cells (DCs), CD4T cells, and regulatory T cells (Tregs), which may account for the clinical feature and absence of antibody response. This case may shed new light on the outbreak management related to control/prevention, treatment, and vaccination of SARS-CoV-2 and other virus infections in immunocompromised individuals.