The Importance of Detecting Neutralizing Antibodies

Neutralizing antibodies is a specific type of antibody that is capable of keeping an infectious agent such as SARS-CoV-2 from infecting a cell by neutralizing or inhibiting its biologic effect.

People who were infected with SARS-CoV-2 or have been vaccinated, developed protective immunity, but the degree and duration of this protection are poorly understood, and vary from person to person. 


In the United States, the vaccines (Pfizer, Moderna, Johnson & Johnson, and Novavax) are authorized for use to produce neutralizing antibodies and immune cells known as memory T cells against the SARS-CoV-2 spike protein. These vaccines teach your body to produce neutralizing antibodies and immune cells in defending against SARS-CoV-2.

If exposed to SARS-CoV-2 at a later point in time, neutralizing antibodies from the vaccines bind to the spike protein on the virus’s surface and neutralize the virus, preventing it from infecting the cells.

A major question associated with the global mass vaccination efforts is the duration of protection. Longitudinal human studies detecting both total IgG as well as neutralizing specific antibodies support a decline in their levels over time and animal studies have shown a direct correlation to neutralizing antibody levels and susceptibility to SARS-CoV-2 reinfection. However, these data have not yet been fully verified in humans and therefore the specific measurable molecular determinants that trigger the requirements for a booster shot remain to be revealed.

Neutralizing antibodies will likely play a role and can be measured semi-quantitively to investigate the correlation of their levels post infection/recovery and/or post-vaccination with protection. Therefore, to mitigate continued pandemic waves of infection globally, the periodic measurement of neutralizing antibody titer levels may reveal a minimal titer required for protection and the potential requirement for booster vaccination.

The SARS-CoV-2 Neutralization Antibody Detection kit has demonstrated 100% concordance with bioassay, which is considered the gold standard for evaluation of NAb activity.

SARS-CoV-2 pandemic control continues to be a challenge globally and is further complicated by the distribution of different vaccines with varying efficacies towards the variant strains. The question around the longevity of immunity post-vaccination remains unanswered but the periodic measurement of neutralizing antibody titers may provide a good indication of an individual’s neutralizing antibody blocking status (NAbs).

This SARS-CoV-2 Neutralization Antibody test is a qualitative and semi-quantitative SARS-CoV-2 antibody test that enables clinicians to detect the level of neutralizing antibodies in a patient’s blood sample and assess relative changes over time. With this numerical value, clinicians will have a baseline and be better equipped to track the long-term duration of an individual’s immune response. Comparison of numerical results will help determine how the immune response develops in an individual and persists over time. 

Specifically, individuals will obtain answers to the following questions:

  • Is there evidence of a prior infection?

  • Is there evidence that a robust immune response was developed from either infection or vaccination?

  • Is there evidence the immune response can provide a level of protected immunity against COVID-19?