Int J Infect Dis. June 20, 2021: S1201-9712(21)00520-8. doi: 10.1016/j.ijid.2021.06.031. Online before printing.
Background: Neutralizing antibodies (NAbs) are important to prevent reinfection with COVID-19. We compared two NAb-related tests, namely the hemagglutination test (HAT) and the replacement virus neutralization test (sVNT).
Methods: The specificity of HAT was compared with sVNT, and the sensitivity and durability of antibodies in patients with different disease severity were evaluated in a cohort of 71 patients at 4 to 6 weeks and 13 to 16 weeks. The kinetic assessment of patients with acute diseases of different severity was performed in the first, second and third weeks.
Results: The specificity of HAT is >99%, and the sensitivity is similar to that of sVNT, but lower than that of sVNT. The level of HAT is significantly positively correlated with the level of sVNT (Spearman’s r = 0.78, p<0.0001). Compared with patients with mild disease, patients with moderate and severe disease have higher HAT titers. 6/7 severely ill patients had a titer of >1:640 in the second week of onset, while only 5/31 mildly ill patients had a titer of >1:160 in the second week of onset.
Conclusion: Since HAT is a simple and very cheap detection method, it is ideal as an indicator of NAb in resource-poor environments.
Post time: Jun-25-2021