This study describes the development and validation of a new serological assay using MERS-CoV S1 protein in an indirect ELISA format.

This MERS-CoV S1 ELISA enables many serum samples to be tested quickly, without the need for a high-level biocontainment laboratory (PC3 or PC4), with results obtained in approximately five hours.

The MERS-CoV S1 ELISA demonstrated high analytical specificity, with no cross-reactivity observed in serum of animals infected with other viruses, including different coronaviruses.

The findings of this study showed that our MERS-CoV S1 ELISA was more sensitive, but still comparable to the commercial EUROIMMUN ELISA (Se 99.4% vs 84.9%).

The MERS-CoV S1 ELISA could be used for determining population freedom from infection and prevalence of infection/surveillance for studying the epidemiology of MERS-CoV in camels and alpacas.

This MERS-CoV S1 ELISA has been shown to represent a cheap, rapid, robust, and reliable assay for surveillance of MERS-CoV in camels in endemic regions.

This study describes the development and preliminary validation of a new serological assay using MERS-CoV S1 protein in an indirect enzyme-linked immunosorbent assay (ELISA) format. This assay has the advantage of being able to test MERS-CoV serum samples in a PC2 laboratory without the need for a high-level biocontainment laboratory (PC3 or PC4), which requires highly trained and skilled staff and a high level of resources and equipment. Furthermore, this MERS-CoV S1 ELISA enables a larger number of samples to be tested quickly, with results obtained in approximately five hours. The MERS-CoV S1 ELISA demonstrated high analytical specificity, with no cross-reactivity observed in serum of animals infected with other viruses, including different coronaviruses. We tested 166 positive and 40 negative camel serum samples and have estimated the diagnostic sensitivity (DSe) to be 99.4% (95% CI: 96.7 – 100.0%) and diagnostic specificity (DSp) to be 100% (95% CI: 97.2%-100.0%) relative to the assigned serology results (ppNT and VNT) using a S/P ratio cut-off value of >0.58. The findings of this study showed that our MERS-CoV S1 ELISA was more sensitive than the commercial EUROIMMUN ELISA (Se 99.4% vs 84.9%) and comparable to the ppNT assay, and therefore could be used as a diagnostic aid in countries in the Middle East where MERS-CoV is endemic in dromedary camels. The assay reagents and protocol were easily adapted and transferred from an Australian laboratory to a laboratory in the University of Hong Kong. Thus, the results described here show that the MERS-CoV S1 ELISA represents a cheap, rapid, robust, and reliable assay to support surveillance of MERS-CoV in camels in endemic regions.

diagnostic sensitivity

diagnostic specificity

enzyme-linked immunosorbent assay

Middle Eastern Respiratory Syndrome Coronavirus

micro-plate neutralization assay

physical containment level

pseudoparticle neutralisation test

MERS-CoV Spike glycoprotein subunit 1

virus neutralization test

MERS-CoV

EUROIMMUN ELISA

MERS-CoV S1 ELISA

© 2024 The Authors. Published by Elsevier B.V.