Although many COVID-19 laboratory-based or point-of-care antibody test kits are commercially available to measure IgG, IgM, IgA, or total antibody response, none is capable of measuring neutralizing antibodies. 

Virus neutralization is the term to describe blocking of binding between the virus and its receptor. Conventional (using SARS-CoV-2 in a BSL3 setting) and pseudovirus Virus Neutralization Testing (VNT) are the main accepted platforms for detection of neutralizing antibodies. However, both require live viruses and cells, highly skilled operators, and days to obtain results and are thus not suitable for mass production and testing on a commercial scale.

The scientific community and policymakers, have shifted focus from acute diagnostic strategies and capacity to the use of serology as an important part of a ‘lockdown exit strategy’, relying on accurate assessment of infection prevalence and protective immunity at the individual and population (herd) levels.

AffinityImmuno has succeeded in developing a cell free, rapid, and sensitive virus neutralization assay that can be used to assess the presence of antibodies that block interaction between the spike protein and ACE2 protein. This assay is able to sensitively measure the presence of blocking antibodies that current IgG and IgM antibody methods are not able to differentiate from total binding antibodies (non neutralizing). This type of testing will be critical to monitoring population immunity, vaccine response, and better managing lockdown exit strategies.