Sars-Cov-2 Neutralising Antibody Testing In Europe: Towards Harmonisation Of Neutralising Antibody Titres For Better Use Of Convalescent Plasma And Comparability Of Trial Data

We compared the performance of SARS-CoV-2 neutralising antibody testing between 12 European laboratories involved in convalescent plasma trials. Raw titres differed almost too-fold differences between laboratories when blind-testing 15 plasma samples. Calibration of titres in relation to the reference reagent and standard curve obtained by testing a dilution series reduced the inter-laboratory variability ca to-fold. The harmonisation of neutralising antibody quantification is a vital step towards determining the protective and therapeutic levels of neutralising antibodies.