Because they target different SARS-CoV-2 proteins, antibody tests among different manufacturers currently can't analytically be compared, according to Siemens. In an effort to address this problem, the new collaboration with the CDC and JRC aims to develop a process to standardize these assays by anchoring each protein to a neutralization antibody titer, a level of antibody present to block the virus from entering cells in laboratory experiments.

By defining concentrations of antibodies to specific viral proteins that confer neutralization, these results could one day be extrapolated to thresholds considered sufficient to confer immunity, the company said. All manufacturers would then be expected to utilize this framework.

WHO cautions against coronavirus 'immunity passports'
The World Health Organization (WHO) has published a report expressing caution about the value of antibody tests for the novel coronavirus and saying that...