A surrogate assay for measuring Coxsackievirus A6 neutralizing antibodies

Abstract

Coxsackievirus A6 (CV-A6) is one of pathogens causing hand, foot and mouth disease (HFMD) and becomes a new challenge to HFMD control. In this study, we first built a single-round pseudovirus infection system for CV-A6, and then developed a pseudovirus luciferase assay (PVLA) for anti-CV-A6 neutralizing antibody (NtAb) quantification. Since cytopahtic effect (CPE) is considered as the gold standard test for anti-enterovirus NtAb detection, a comparison study has been performed using 318 clinical serum samples, as measured both by PVLA and CPE. The sensitivity and specificity of PVLA was 94.9% (95% CI between 90.8-97.5%) and 92.7% (95% CI between 86.6-96.6%), respectively. Statistical analysis revealed that PVLA and CPE were highly correlated (spearman r = 0.931, P < 0.0001) and in good agreement (94.0%, 95% CI between 90.8-96.4%), showing that PVLA could be used as a surrogate assay for anti-CV-A6 NtAb detection and served as a valuable tool for CV-A6 vaccine evaluation and CV-A6 epidemiological surveillance.

Development of a pseudovirus-based assay for measuring neutralizing antibodies against Coxsackievirus A10

“…[16][17][18][19] Our research group has already constructed numerous types of pseudoviruses relevant to HFMD, including pseudoviruses of enterovirus 71 (EV-A71), CV-A16, CV-B3, CV-B5, and CV-A6, which were used in the development of a pNT assay. [20][21][22][23][24] Here, we report the successful construction of a CV-A10 pseudovirus, and development of a CV-A10 pNT to detect the titre of anti-CV-A10 NtAb. The method was validated using 67 clinical serum samples, and the performance and safety were compared to those of the traditional cNT method.…”