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
Dung Nguyen, Peter Simmonds, Maurice Steenhuis, Elise Wouters, Daniël Desmecht, Mutien‐Marie Garigliany, Márta Romano, Cyril Barbezange, Piet Maes, Bram Van Holm, Joaquín Mendoza, Salvador Oyonarte, Anders Fomsgaard, Ria Lassaunière, Eva Žusinaite, Katarina Resman Rus, Tatjana Avšič‐Županc, Johan Reimerink, Fiona Brouwer, Marieke Hoogerwerf, Chantal Reusken, Gunnveig Grødeland, Sophie Le Cam, Pierre Gallian, Abdennour Amroun, Nadége Brisbarre, Christophe Martinaud, Isabelle Leparc Goffart, Hubert Schrezenmeier, Hendrik B. Feys, C. Ellen van der Schoot, Heli Harvala
Abstract
We compared the performance of SARS-CoV-2 neutralising antibody testing between 12 European laboratories involved in convalescent plasma trials. Raw titres differed almost 100-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 10-fold. The harmonisation of neutralising antibody quantification is a vital step towards determining the protective and therapeutic levels of neutralising antibodies.