The body immune system produces neutralizing antibodies (NAb) which are a subgroup of the IgG antibodies that specifically bind to the receptor binding domain (RBD) of S-protein on the surface of the Coronavirus SARS-CoV-2. NAb are effective to block the viral infection of human cells by neutralizing RBD and preventing it from attaching to human cells.

Nabs inactivate the entry of invading Coronavirus in human cells by neutralizing the RBD-ACE2 interaction, thus providing protective immunity against Covid-19 infection and possible re- infection.

No Covid-19 vaccine is 100% effective; therefore, odds are low. A very small number of fully vaccinated people have been infected with the coronavirus, called “breakthrough infections”. If you do get infected after your vaccination, the higher the amount of the Neutralizing Antibodies you have more likely your case will be mild or asymptomatic infection. Individual response may vary and hence consult your doctor.

SPARK CoV-Check NAb Test is designed with specific and proprietary antibodies that selectively detect the RBD binding domains of the NAb with high degree of sensitivity and specificity. The calibration curve for each batch is produced with WHO-listed titer standards measured in BAU/ml in range of <50 bau/ml (very low immunity) to >1500 bau/ml (very high immunity)

Each batch is calibrated with at least 15 different known standards serum control samples. Each control standard is precisely calibrated as per the WHO-titer standards.

Spark’s award-winning technology of mobile phone application takes a camera picture of the test cassettes and is used as a “reader” to convert the intensity reading in the test line in the cassette to NAb titer concentration.  The calibration is generated as per the calibration curve for the concentration range of the titer.