Title : Multiplexed serology assays for detection of IgG antibodies against Mpox and vaccinia viruses
Abstract:
Monkey pox (Mpox) virus (MPXV) spreads through skin-to-skin contact, causing painful lesions. The 2022 outbreak resulted in the Congo’s worst surge on record, with the subsequent world-wide spread causing nearly 20,000 suspected cases and 820 suspected deaths. Effective tools for understanding MPXV immune responses are needed for developing timely and effective MPXV-specific vaccines, as well as for understanding the immune correlates of protection from natural infection and/or vaccination. Despite a rapid increase in the number and availability of serology assays that can detect antibodies against MPXV, there is limited information available on their performance and validation status.
In addition, most of these assays are low throughput and measure responses to a single antigen, which cannot capture the breadth of antibody responses to MPXV. Here we present a validated, quantitative, multiplexed serology assay to measure antibody responses towards 5 MPXV and 5 vaccinia virus (VACV) variant recombinant proteins. Vaccinia is included in the panel due to its common ancestry to MPXV and the prevalence of smallpox vaccination, which is expected to prevent or reduce the severity of MPXV infection.
Viral antigens that elicit strong T cell and B cell immune responses were chosen for the panel and include the receptor binding site for MPXV (A29L) and VACV (A27L), outer envelope proteins (MPXV: B6R, A35R and VACV: B5R, A33R) and inner membrane proteins (MPXV: M1R, E8L and VACV: L1R, D8L). The assay uses a 10-spot 96-well plate coated with the 5 MPXV and 5 VACV antigens, along with an electrochemiluminescent (ECL) detection system. The assay simultaneously detects IgG antibodies to all 10 proteins. Specificity was assessed using purchased serum sample sets that were either collected pre-epidemic from aged smallpox-vaccinated individuals, or during the outbreak from convalescent individuals who recently recovered from MPXV infection. The multiplex MPXV ECL serology assay allows for sensitive, high throughput, and simultaneous measurement of IgG levels to multiple antigens in human sera, supporting its use in research, epidemiology, and vaccine testing.
Audience Take Away Notes:
- Explain how the audience will be able to use what they learn? A multiplex method for testing at-risk populations to distinguish between vaccinated and/or mpox-infected individuals versus negative individuals
- How will this help the audience in their job? They can use the V-PLEX Orthopoxvirus Serology Kit for screening a population at risk for MPOX, for surveillance, in high throughput, and simultaneously measure IgG levels to multiple MPOX and Vaccinia Orthopoxvirus antigens supporting exploratory R&D to design treatments, assess mechanism of action, for correlate of protection work.
- Is this research that other faculty could use to expand their research or teaching? Yes, MSD multiplex sample testing platforms cover a wide range of biomarkers.
- Does this provide a practical solution to a problem that could simplify or make a designer’s job more efficient? Yes, rather than perform singleplex assays, this allows measurement of 10 Orthopoxvirus antigens in 1 well, saving on sample volume, giving more consistent measurement, saving time, money and volume for method development
- Will it improve the accuracy of a design, or provide new information to assist in a design problem? Yes, it will ensure there is no variability in the measurement due to differences due to variables relating to using 10 different singleplex assays- which requires higher sample volume, a variety of pipetting days, freeze/thaw cycles and methods. Ten Orthopoxvirus antigens are assessed for functional IgG concentration simultaneously.
- List all other benefits. The V-PLEX Orthopoxvirus Serology Kit is a validated, quantitative, multiplexed RUO serology kit that accurately and precisely quantifies IgG antibodies against the Mpox and VACV proteins (VACV A27L, VACV A33R, VACV B5R, VACV D8L, VACV L1R, MPXV M1R, MPXV E8L, MPXV B6R, MPXV A35R and MPXV A29L).
