Emerg Microbes Infect . Serological Differentiation Between COVID-19 and SARS Infections

[tetano]

Emerg Microbes Infect


. 2020 Jun 12;1-23.
doi: 10.1080/22221751.2020.1780951. Online ahead of print.
Serological Differentiation Between COVID-19 and SARS Infections


Wan Ni Chia ¹ , Chee Wah Tan ¹ , Randy Foo ¹ , Adrian Eng Zheng Kang ¹ , Yilong Peng ¹ , Velraj Sivalingam ¹ , Charles Tiu ¹ , Xin Mei Ong ¹ , Feng Zhu ¹ , Barnaby E Young ^{2 3 4} , Mark I C Chen ^{2 5} , Yee-Joo Tan ^{6 7} , David C Lye ^{2 3 4 8} , Danielle E Anderson ¹ , Lin-Fa Wang ¹



Affiliations

• PMID: 32529906
• DOI: 10.1080/22221751.2020.1780951

Abstract

In response to the coronavirus disease 2019 (COVID-19) outbreak, caused by the SARS-CoV-2 virus, multiple diagnostic tests are required globally for acute disease diagnosis, contact tracing, monitoring of asymptomatic infection rates and assessing herd immunity. While PCR remains the frontline test of choice in the acute diagnostic setting, serological tests are urgently needed to fulfil the other requirements. Unlike PCR tests which are highly specific for each virus, cross-reactivity could potentially be a major challenge for COVID-19 antibody tests considering there are six other coronaviruses known to infect humans. Among the human pathogens, SARS-CoV is genetically most related to SARS-CoV-2 sharing approximately 80% sequence identity and both belong to the species SARS related coronavirus (SARSr-CoV) in the genus Betacoronavirus of family Coronaviridae. In this study, we developed and compared the performance of four different serological tests to comprehensively assess the cross-reactivity between COVID-19 and SARS patient sera. Our results indicate that there is a significant cross-reactivity when N protein of either SARS-CoV or SARS-CoV-2 is used. The S1 or RBD derived the spike (S) protein offers better specificity. Amongst the different platforms, capture ELISA performed best. Finally, we found that SARS survivors all have significant level of antibodies remaining in their blood 17 years after infection. We discovered that anti-N antibodies waned more than anti-RBD antibodies, and the latter is known to play a more important role in providing protective immunity.

Keywords: Antibody; COVID-19; SARS; SARS-CoV-2; Serology.