Reduced sensitivity of antibody tests after omicron infection

In the past years, a huge variety of serological assays have been developed to detect antibodies binding to the nucleocapsid or the spike protein of SARS-CoV-2. The majority of these tests were developed and validated with sera from individuals infected with pre-omicron virus variants while highly mutated SARS-CoV-2 variants have since emerged. Omicron, the most-recently described variant of concern (VOC) and its subvariants contain highly-mutated spike proteins that escape immunity induced by pre-omicron variant infection or vaccination.