Accurate SARS-CoV-2 seroprevalence surveys require robust multi-antigen assays
C Fotis, N Meimetis, N Tsolakos, M Politou, K Akinosoglou, V Pliaka, A Minia, E Terpos, I Trougakos, A Mentis, M Marangos, G Panayiotakopoulos, M Dimopoulos, C Gogos, A Spyridonidis, L Alexopoulos
Received date: 5th November 2020
There is a plethora of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) serological tests based either on nucleocapsid phosphoprotein (N), S1-subunit of spike glycoprotein (S1) or receptor binding domain (RBD). Although these single-antigen based tests demonstrate high clinical performance, there is growing evidence regarding their limitations in epidemiological serosurveys. To address this, we developed a Luminex-based multiplex immunoassay that detects total antibodies (IgG/IgM/IgA) against the N, S1 and RBD antigens and used it to compare antibody responses in 1,225 blood donors across Greece. Seroprevalence based on single-antigen readouts was strongly influenced by both the antigen type and cut-off value and ranged widely [0.8% (95% CI, 0.4-1.5%)-7.5% (95% CI, 6.0-8.9%)]. A multi-antigen approach requiring partial agreement between RBD and N or S1 readouts (RBD&N|S1 rule) was less affected by cut-off selection, resulting in robust seroprevalence estimation [0.6% (95% CI, 0.3-1.1%)-1.2% (95% CI, 0.7-2.0%)] and accurate identification of seroconverted individuals.
This is an abstract of a preprint hosted on a preprint server, which is currently undergoing peer review at Scientific Reports. The findings have yet to be thoroughly evaluated, nor has a decision on ultimate publication been made. Therefore, the results reported should not be considered conclusive, and these findings should not be used to inform clinical practice, or public health policy, or be promoted as verified information.