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Updated: Mar 24, 2026
Author Spotlight: A Pseudotype Virus System for Assessing Omicron Subvariants and Neutralizing Antibodies in SARS-CoV-2 Research
Published on: September 8, 2023
A rapid and quantitative assay for measuring neutralizing antibodies of Coxsackievirus B3
Pan Chen1, Xing Wu2, Qunying Mao2
1National Institutes for Food and Drug Control, Beijing 100050, China; National Institute of Biological Sciences, Beijing 102206, China.
Insights
A new Coxsackievirus B3 (CVB3) pseudovirus system accurately quantifies neutralizing antibodies (NtAbs). This tool reveals low CVB3 immunity in children, highlighting a need for vaccine development.
Area of Science:
- Virology
- Immunology
- Epidemiology
Background:
- Coxsackievirus B3 (CVB3) is an increasing cause of hand, foot, and mouth disease (HFMD), particularly in preschool children.
- CVB3 poses a significant health risk to young children due to their potential lack of immunity.
Purpose of the Study:
- To establish a novel single-round infection system for CVB3 using pseudoviruses.
- To develop a rapid and quantitative assay for measuring neutralizing antibody (NtAb) levels against CVB3.
- To assess the seroprevalence of CVB3 NtAbs in preschool children and adults.
Main Methods:
- Reverse genetics approaches were used to create a CVB3 pseudovirus system.
- Pseudoviruses were generated by transfecting CVB3 capsid expresser plasmids and CVB3 replicon RNA with a firefly luciferase reporter.
- The pseudovirus system was employed to quantify NtAbs in 720 human serum samples.
Main Results:
- The CVB3 pseudovirus system demonstrated superior specificity and sensitivity compared to traditional cytopathic effect (CPE) assays.
- Seroprevalence studies revealed only 11.94% NtAb positivity in preschool children, suggesting widespread susceptibility.
- A significantly higher NtAb positive rate (60%) was observed in adults, indicating prior CVB3 exposure.
Conclusions:
- The developed CVB3 pseudovirus assay is a rapid and quantitative tool for evaluating population-level NtAb responses.
- Findings suggest most preschool children are immunologically naive to CVB3, underscoring the need for effective interventions.
- This assay is expected to accelerate the development of CVB3 vaccines.
Abstract:
Coxsackievirus B3 (CVB3) infection has been found to account for an increasing proportion cases of hand, foot and mouth disease (HFMD) in recent epidemiology studies. CVB3 is a single stranded, non-enveloped RNA virus and the infection can cause prominent health threat to pre-school children. Here, by taking approaches of reverse genetics, we established a single-round infection system for CVB3. The pseudovirus was produced by sequential transfection of CVB3 capsid expresser plasmid and CVB3 replicon RNA bearing firefly luciferase as a reporter. The CVB3 pseudovirus system was used for quantifying neutralizing antibody (NtAb) levels of 720 human serum samples and showed superior specificity and sensitivity comparing traditional cytopathic effect (CPE) assay. Furthermore, we compared the seroprevalence of CVB3 NtAbs in pre-school children and healthy adults, and found that only 11.94% of pre-school children were NtAbs positive which suggested that most children were naive to CVB3 infection; while there is much higher positive rate in adults (60%) indicating that most adults have experienced CVB3 infection during childhood. This rapid and quantitative assay greatly facilitates evaluating the level of NtAbs against CVB3 in populations and will help to advance CVB3 vaccine development.
