Eurofins Launches Quantitative Antibody Test to Measure Immune Response to COVID-19 and Vaccines

This ELISA kit can support vaccination campaigns by confirming the success of a vaccination and monitoring the antibody levels over time.

Vaccination against COVID-19 is a critical element in the fight against the pandemic. The spike protein covers the surface of the SARS-CoV-2 virus and is responsible for attachment and invasion of human cells. All currently approved vaccines use the spike protein to train the immune system to detect and neutralize this virus. The GSD NovaLisa SARS-CoV-2 (COVID-19) quantitative IgG is an ELISA assay designed to mimic this target by using the native, trimeric form of the spike protein and detect all long-lasting IgG antibodies raised by a vaccination or natural infection. A standard curve allows for quantification to monitor if antibody levels increase or decrease over time.

Currently, it is not known how long a vaccination will protect from COVID-19 and if a booster vaccination might be required if the antibody levels drop below a certain threshold that is currently not scientifically established. Supporting the establishment of an international reference value, the new assay is calibrated against the first WHO International Standard (NIBSC code: 20/136). This provides customers with the option to report results in international standard units.

Supplementary to vaccination monitoring, the kit shows excellent clinical performance in detecting antibodies raised naturally by a true SARS-CoV-2 infection. 15 days after symptom onset, the assay identifies antibodies to the spike protein in 97% of patients with a PCR confirmed infection. A diagnostic specificity of 99.94% was validated with over 500 samples from healthy controls. Validation of the test with capillary blood samples enables its use with self-sampling devices for less invasive and more comfortable sample collection that could simplify large scale screening programs. Combining this new assay with our established ELISA IgG may distinguish between vaccinated individuals and those that went through an infection.