Chris Mok and Tomas Lv published with Malik Peiris, Co-Director at HKU-Pasteur, and Leo Poon, School of Public Health (HKU), in Eurosureveillance on serological assays for SARS-CoV-2:
The true severity of COVID-19 remains a major knowledge gap because mild or asymptomatic infections are difficult to estimate. The invisible "iceberg" of mild infections needs to be estimated to fully assess disease severity.
"Population-based sero-epidemiology studies provide crucial information to assess development of herd immunity and calibrate our response to this pandemic" says Malik Peiris, Co-Director at HKU-Pasteur
In order to carry out age-stratified population-based sero-epidemiology, it is important to validate serological methods that can be used in such large-scale studies. HKU-Pasteur Research Pole and the School of Public Health at HKU have developed an ELISA assay biosafety level 2 containment, based on the recombinant receptor-binding domain (RBD) of the SARS-CoV-2 spike protein for use as a screening assay, and neutralization tests using live virus in biosafety level 3 containment as confirmatory tests. The RBD ELISA assay is specific and correlates well with a confirmatory test with neutralization, which provides greater assurance of protection.
"The RBD ELISA can be completed in a day, whereas the neutralization confirmation takes 4 days more"
says Chris Mok, team leader at HKU-Pasteur.
Thus, screening with our ELISA assay is a reliable approach for large-scale sero-epidemiological studies, which are crucial to assess infection attack rates in the population and to accurately define disease severity and herd immunity.