Abstract
Background: Neutralizing antibodies (NAbs) are important for protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection. In this study, two assays that are correlated with NAbs were compared: the haemagglutination test (HAT) and the surrogate virus neutralization test (sVNT).
Methods: The specificity of the HAT was compared with the sVNT, and the sensitivity and persistence of antibodies in patients with varying severity of illness was assessed in a cohort of 71 patients at 4-6 weeks and 13-16 weeks. The kinetics were assessed in the first, second, and third weeks in patients with varying severity of acute illness.
Results: The specificity of the HAT was >99%, and sensitivity was similar to the sVNT. The levels of HAT were significantly and positively correlated with those of the sVNT (Spearman’s r = 0.78, P < 0.0001). Patients with moderate and severe illness had higher HAT titres when compared to those with mild illness. Six of seven patients with severe illness had a titre of >1:640 during the second week of illness, whereas only five of 31 patients with a mild illness had a titre of >1:160 in the second week of illness.
Conclusions: Since the HAT is a simple and very cheap assay to perform, it would be ideal to use as an indicator of NAbs in resource-poor settings.
Keywords: COVID-19; Disease severity; Haemagglutination assay; Neutralizing antibodies; Surrogate neutralization assay.
【저자키워드】 COVID-19, Neutralizing antibodies, disease severity, Haemagglutination assay, surrogate neutralization assay, 【초록키워드】 SARS-CoV-2, coronavirus, Neutralizing antibodies, antibody, severity, disease severity, severe acute respiratory syndrome Coronavirus, sensitivity, specificity, Kinetics, Reinfection, Cohort, Neutralization assay, persistence, virus neutralization test, neutralization test, Patient, respiratory, moderate, surrogate virus neutralization test, NAb, severity of illness, Indicator, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, NAbs, sVNT, titre, mild illness, surrogate, acute illness, Spearman, FIVE, Seven, significantly, correlated, positively correlated, were assessed, 【제목키워드】 neutralizing antibody, Receptor binding domain, IgG antibody, marker, COVID-19 patient, detect,