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J Virol Methods
. 2024 Apr 20:114945.
doi: 10.1016/j.jviromet.2024.114945. Online ahead of print. Validation of a severe acute respiratory syndrome coronavirus 2 microneutralization assay for evaluation of vaccine immunogenicity
Stephanie Hamilton 1 , Mingzhu Zhu 2 , Shane Cloney Clark 3 , Penny Mayes 4 , Jen Fenner 5 , Leah Cui 6 , Rongman Cai 7 , Raj Kalkeri 8 , Louis F Fries 9 , Melinda Pryor 10 , Joyce Plested 11
Affiliations
As variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to emerge, assessment of vaccine immunogenicity remains a critical factor to support continued vaccination. To this end, an in vitro microneutralization (MN50) assay was validated to quantitate SARS-CoV-2 neutralizing antibodies against prototype and variant strains (Beta, Delta, Omicron BA.1, Omicron BA.5, and XBB.1.5) in human serum. For the prototype strain, the MN50 assay met acceptance criteria for inter-/intra-assay precision, specificity, linearity, and selectivity. The assay was robust against changes to virus/serum incubation time, cell seeding density, virus content per well, cell passage number, and serum interference. Analyte in serum samples was stable up to five freeze/thaw cycles and for up to 12 months of storage at -80 ± 10 °C. Similar results were observed for the variant-adapted MN50 assays. The conversion factor to convert assay result units to WHO international standard units (IU/mL) was determined to be 0.62 for the prototype strain. This MN50 assay will be useful for vaccine immunogenicity analyses in clinical trial samples, enabling assessment of vaccine immunogenicity for ancestral and variant strains as variant-adapted vaccines are developed.
Keywords: BSL-3; COVID-19; Live virus; MN50; Omicron variant; SARS CoV-2; Wildtype; XBB.1.5; microneutralization; variants of concern.
. 2024 Apr 20:114945.
doi: 10.1016/j.jviromet.2024.114945. Online ahead of print. Validation of a severe acute respiratory syndrome coronavirus 2 microneutralization assay for evaluation of vaccine immunogenicity
Stephanie Hamilton 1 , Mingzhu Zhu 2 , Shane Cloney Clark 3 , Penny Mayes 4 , Jen Fenner 5 , Leah Cui 6 , Rongman Cai 7 , Raj Kalkeri 8 , Louis F Fries 9 , Melinda Pryor 10 , Joyce Plested 11
Affiliations
- PMID: 38649070
- DOI: 10.1016/j.jviromet.2024.114945
As variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to emerge, assessment of vaccine immunogenicity remains a critical factor to support continued vaccination. To this end, an in vitro microneutralization (MN50) assay was validated to quantitate SARS-CoV-2 neutralizing antibodies against prototype and variant strains (Beta, Delta, Omicron BA.1, Omicron BA.5, and XBB.1.5) in human serum. For the prototype strain, the MN50 assay met acceptance criteria for inter-/intra-assay precision, specificity, linearity, and selectivity. The assay was robust against changes to virus/serum incubation time, cell seeding density, virus content per well, cell passage number, and serum interference. Analyte in serum samples was stable up to five freeze/thaw cycles and for up to 12 months of storage at -80 ± 10 °C. Similar results were observed for the variant-adapted MN50 assays. The conversion factor to convert assay result units to WHO international standard units (IU/mL) was determined to be 0.62 for the prototype strain. This MN50 assay will be useful for vaccine immunogenicity analyses in clinical trial samples, enabling assessment of vaccine immunogenicity for ancestral and variant strains as variant-adapted vaccines are developed.
Keywords: BSL-3; COVID-19; Live virus; MN50; Omicron variant; SARS CoV-2; Wildtype; XBB.1.5; microneutralization; variants of concern.