Abnova’s COVID-19 Human IgM IgG Rapid Test Gains CE-IVD Approval and Sales Order from Abroad

Neihu, Taiwan (July 13, 2020)

Abnova announced today that its COVID-19 Human IgM IgG Rapid Test has gained CE-IVD approval and sales order from abroad. Abnova’s COVID-19 rapid test measures the human IgM and IgG antibody as an indication of COVID-19 infection. Abnova uses two COVID-19 recombinant proteins, N (nucleocapsid) and RBD (residue binding domain) proteins, as double probes for circulating IgM and IgG antibody detection. In contrast, all of the competitors use either N or RBD protein, as a single probe in their rapid tests. The use of double proteins enables capture of all COVID-19 IgM and IgG antibodies for greater detection sensitivity. On the other hand, such rapid test is more difficult to develop as a product.

Roche and Abbott use N protein while Siemens and Beckman Coulter use the RBD proteins as the capture probe. COVID-19 N protein is more conserved and has less cross reactivity among the coronaviruses including SARS, MERS, and common cold coronaviruses. COVID-19 RBD protein, being a shorter length spike S protein, also has less cross reactivity among the coronaviruses. Patient’s neutralization antibody also targets the RBD fragment of the S protein. However, not all RBD antibodies are neutralization antibodies. Another test is required to fully identify the COVID-19 neutralization antibody. Combined use of both N and RBD proteins require more rigorous preclinical and clinical testing and validations.

RT-PCR test is currently the gold standard test for COVID-19 detection and identification. After the initial infection, the human body mounts an innate immune response against the virus with IgM antibody within 2 weeks and IgG antibody within 4 weeks of infection. The rise of antibody coincides with the decrease of viral load. A negative COVID-19 RT-PCR test does not completely rule out the absence of infection, especially if the signs and symptoms of infection persist. An IgM IgG antibody would be complementary test to identify and quarantine the patient to control COVID-19 transmission.