Clinical signs and symptoms of respiratory viral infection due to SARS-CoV-2 and influenza can be similar. SARS-CoV-2, influenza A and influenza B viral antigens are generally detectable in upper respiratory specimens during the acute phase of infection.

Influenza virus belongs to the family of Orthomyxoviridae, and immunologically diverse, single-stranded RNA viruses. There influenza A and B virus is the main pathogen that severe illnesses both in human and in many animal species. Based on the current epidemiological investigation, the incubation period is 1 to 4 days. The main manifestations include acute fever, general aching and respiratory symptoms. Both Type A and B viruses can circulate simultaneously, but usually one type is dominant during a given season.1

COVID-19 is an acute respiratory infectious disease. People are generally susceptible. Currently, the patients infected by the novel coronavirus are the main source of infection; asymptomatic infected people can also be an infectious source. Based on the current epidemiological investigation, the incubation period is 1 to 14 days, mostly 3 to 7 days. The main manifestations include fever, fatigue and dry cough. Nasal congestion, runny nose, sore throat, myalgia and diarrhea are found in a few cases.

KaiBiLi^TM Flu & COVID-19 Antigen Duo Rapid Test is intended for the simultaneous qualitative detection and differentiation of the nucleocapsid protein antigens from SARS-CoV-2, influenza A and influenza B in direct nasopharyngeal (NP) specimens. The detection is based on the antibodies which were developed specifically recognizing and reacting with the nucleoprotein of virus.